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55? HIGH DEFINITION TV THE LATEST NEWS $2.25 AUGUST 1987 IN CANADA SZ.75 LOGY - VIDEO - STEREO - COMPUTERS - SERVICE g) GERNSBACK Listen to hidden signals on the FM band & of CE What it means to be a Certified Electronics Technician nn»m j ... i *< ^ For automated control of your line -powered devices ^ »-t J :♦ 4 i ii I M" SCA/FM STEREO RECEIVER STEREO POWER ro<S) A design primer ROBOT Software that makes your robot go! ComputbrDicest IBM's new PS 2 TUNE ^ fmJL SCA" ON TUNING D O POWER VOLUME PHONES 71896 48783 t Video News New Products Satellite TV Audio Update NOW GET SCOPE, COUNTER AND DMM INPUT ALL AT ONCE THROUGH ONE PROBE! 3^1388 l&d88.8-[> J r C TU Gated frequency measurement. B sweep triggering during the intensified portion of the A sweep. Intensified portion frequency is measured with the counter/timer/ DMM. Delay time measurement. Delay time from the start of A sweep to the start of the B sweep is mea- sured with crystal accuracy. Channel 1 dc volts measure- ment. The average dc compo- nent of a waveform is measured directly through channel 1 with direct digital fluorescent readout. The Tek 2236 combines 100 MHz, dual timebase scope capability with counter/timer/DMM functions integrated into its vertical, horizontal and trigger systems. For the same effort it takes to display a waveform you can obtain digital readout of frequency, period, width, totalized events, delay time and A-time to accuracies of 0.001%. The same probe is used to provide input for the CRT display and the digital measurement system, resulting in easy set-up. greater measurement confi- dence and reduced circuit loading. Probe tip volts can also be measured through theCh 1 input. Precision measurements at the touch of a button. Auto-ranging frequency, period, width and gated measurements are push- button-simple. And the 2236 offers an independent float- ing 5000 count, auto-rang- ing multimeter with side inputs for DC voltage mea- B and width 100 MHz No of Channels 2 + Trig. View Max. Sweep Speed 5 ns/div Digital Readout Features Direct Ch 1 Voltage Meas. 0.5% DC; 2.0% AC RMS Resistance: .Otn to 200 Megfi Continuity/Temp: Audible/C or F° Totalizing Counter: — 1 counts to 8,000,000 Direct Freq. Meas: 100 MHz to 0.001% ace. Period, Width Meas: 10 ns with 10 ps max. resolution Timing Meas. Accuracy .001% (delay and A-timewith readout) Trigger Modes P-P Auto, Norm. TV Field, TV Line, Single Sweep Weight 7,3 kg (16.2 lb) Price $2650 Wananty 3-year including CRT (plus optional service plans to 5 years) surementsto0.1%. A built-in, auto-ranging a ohmmeter provides I resistance measurements from 0.01 H to 2Gfi— as well as audible continuity. Automatic diode/junction I detection and operator 1 prompts serve to simplify 1 set-up and enhance 1 confidence in your 1 measurements. J The 2236: scope, counter, timer, DMM plus a 3-year warranty —all for just $2,650. Contact your nearest dis- tributor or call Tek toll-free. Technical personnel on our direct-line will answer your questions and expedite delivery. Orders include probes, 30-day free trial and service worldwide. Call Tek direct: 1-80O433-2323for video tape or literature, 1-800-426-2200 for application assistance or ordering information. In Oregon, call collect: 1-627-2200 Tektronix COMMITTED TO EXCEULENCE Copyright e 1986, Tektronix, Inc. All righls reserved. TTA.797 CIRCLE 92 ON FREE INFORMATION CARD Aug USt 1 98 7 Electronics Vol. 58 No. 8 39 SCA RECEIVER Hear the hidden signals on the FM band. Rudolf Graf and William Sheets 45 VERSATILE DIGITAL TIMER Precisely controls any AC-powered device in your home. Ross Ortman ____ 57 RE ROBOT Part 9. Programming the robot. Steven E. Sarns 75 PC SERVICE Direct-etch foil patterns for the digital timer. 48 HIGH DEFINITION TV The first major change in television since the addition of color is on its way! Josef Bernard 52 CERTIFICATION FOR ELECTRONICS TECHNICIANS The more you learn, the more you can earn. W. Clem Small, GET Hi;M l |^-fl,'i.M iT!TT' 55 TRANSISTOR AMPLIFIER DESIGN A basic design that solves many problems. Jack Cunkleman DHJ^y.'H.'Mih- 6 VIDEO NEWS What's new in this fast- changing field. David Lachenbruch 16 EQUIPMENT REPORTS Regency Informant Scanning Receiver 26 COMMUNICATIONS CORNER Diversity reception and the wireless microphone. Herb Friedman 28 SATELLITE TV HDTV standards. Bob Cooper, Jr, 30 DESIGNER'S NOTEBOOK Logic family translation. Robert Grossblatt 32 AUDIO UPDATE Expert answers. Larry Klein ComputerDicest IBM's NEW PS 2 Brtol graphta, tvper speed DESIGN PC BOHRDS ON VOUft PC N«« ptOftoflH nwhfl it easy PAGE 61 PAGE 48 EKE 100 Advertising and Sales Offices 100 Advertising Index 8 Ask RE 101 Free Information Card 12 Letters 82 Market Center 21 New Lit 24 New Products 4 What's News 1 nrmrn tic unarms QULDTMSSC4/FM STEREO RECEIVER mUCl (rfClTT KU A TBAMWTOW robot* COMTJKM. 1 11 "s SaleUlt* TV Aiifci updal* The FM band abounds with hidden signals. Called SCA broadcasts or transmissions, some carry back- ground music for stores, offices, and restaurants; some carry data for per- sonal and commercial computer users; and some offer special inter- est programming for the handicap- ped and other groups. This month, we tell where those hidden signals are, and what makes them possible. Then we'll show you a receiver that will let you tune into the hidden world of FM radio. The story begins on page 39. ■■iri.mj'.t.i.'yn THE SEPTEMBER ISSUE IS ON SALE AUGUST 4 BUILD THE VIDEO PALETTE Add special color effects to a video signal. BUILD AN UNINTERRUPTIBLE POWER SUPPLY This 40-watt back-up supply kicks in at the first sign of trouble. CELLULAR TELEPHONE TECHNOLOGY Learn about the technology that's revolutionized mobile telephones. RE ROBOT Part 10 deals with robot applications. SCR/TRIAC COOKBOOK Practical SCR/Triac circuits for your next project. As a service to readers. RADIO- ELECTRONICS publishes available plans or information relating to newsworthy products. techniques and scientific and technological developments- Because of possible variances in the quality and condition of materials and workmanship used by readers. RADIO-ELECTRONICS disclaims any responsibility for trie safe and proper functioning of reader-built projects based upon or from plans or information published in this magazine. Since some of the equipment and circuitry described in RADIO-ELECTRONICS may relate to or be covered by U.S. patents, RADIO-ELECTRONICS disclaims any liability for the infringement of such patents by the making, using, or selling of any such equipment or circuitry, end suggests that anyone interested in such projects consult a patent attorney. RADIO ELECTRONICS, (ISSN 0033-7862) August 1987. Published monthly by Gemsback Publications. Inc., 500-B Bi. County Boulevard. Farmingdale, NV 11735 Second-Class Postage paid at Farmingdaie. NYand additional mailing offices, Second-Class mail registration No. g242 authorized at Toronto. Canada. One-year subscription rale U.S.A. and possessions $16.97. Canada $22-97. ell other countries S25.B7, All subscription orders payable in U.S-A, funds only, via international postal money order or check drawn on a U.S.A. bank. Single copies$2-25. r tge7 by Garnsback Publications, Inc. All rights reserved. Printed in USA POSTMASTER: Please send address changes to RADIO-ELECTRONICS. Subscription Dept Box 55115, Boulder. CO 80321-5115. A stamped self- addressed envelope must accompany all submitted manuscripts and/or artwork or photographs if their return is desired should they be rejected. We disclaim any responsibility lor the loss or damage of manuscripts and/or artwork or photographs while in our possession or otherwise. Electronics Hugo Garnsback CI 884-1967) founder M, Harvey Gemsback. editor- in-chief, emeritus Larry Sleekier, EHF, GET. editor-in-chief and publisher EDITORIAL DEPARTMENT Art Kiel ma n, editorial director Brian C. Fenton, managing editor Cari Laron, WB2SLR, associate editor Jeffrey K. Holtzman, assistant technical editor Robert A. Young, assistant editor Julian S. Martin, editorial associate Byron G. Wets, editorial associate M. Harvey Gemsback, contributing editor Jack Darr, CET. service editor Robert F. Scott. se mi co nd u ctc-r ed Itor Herb Friedman, com m u n icati on s ed itor Bob Cooper, Jr. satellite-TV editor Robert Grossblatt, circuits editor Larry Klein, audio editor David Lachenbruch, contributing editor Richard D, Fitch, contributing editor Teri Senduto. editorial assistant PRODUCTION DEPARTMENT Ruby M. Yee, production director Robert A. W. Lowndes, editorial production Andre Duzant, technical illustrator Karen Tucker, advertising production Marcella Amoroso, production traffic CIRCULATION DEPARTMENT Jacqueline P. Cheese boro. circulation director Wendy Alanko, circulation analyst Theresa Lombardo, circulation assistant Typography by Mates Graphics Cover Foto by Bill Peterson, Design Color Labs Radio-Electronics is indexed in Applied Science & Technology Index and Headers Guide to Periodical Liter- attire. Microfilm & Microfiche editions are available- Contact circulation depart- ment for details. Advertising Sales Offices listed on page 100. m More Functions. Smaller Budget. Beckman Industrial Circuitmate" DMMs put hFE, Logic, Capacitance, Frequency and True RMS In Your Hand. For Less. Get more, for less. It's a simple defi- nition of value. For DMMs, value means finding the combination of capabilities that meets your needs at the right price Without losing sight of accuracy and reliability If you want more functions at a low price, Beckman Industrial's Circuitmate" 1 Digital Multimeters are the best value around. From the pocket-sized DM20L to the DM850, with true RMS capability and accu- racy to 0.05% ± 1 digit, Circuitmate DMMs give you the functions you need. For instance, the DM20L puts both a Logic Probe, a transistor gain function (hFE), arid a Hill range of DMM functions in die palm of your hand. For only 569-95. Then diere's the DM25L. Where else does SS995 buy you a Logic Probe, capaci- tance measurement, transistor gain function (hFE), and 24 DMM ranges including resist- ance to 2000 megohms? Nowhere else. When high accuracy counts, there's the DM800 with a 4 Vi digit display The DM800 Is l:MI!nSDN irm DM20L Pocket-Size w/LogieS69.95* TTL Logic Probe: 20MHz Hi/lo/off indications Detects 25nS pulse widths iiFE(NPNorPNP): 1 range (1000) DMM: Input Impedance— 10 Megohms DCA/ACA-5 ranges (SfflVAtoMl Otlnts-8 ranges (200 ohms to 2000 Megohms) Continuity beeper also gives you frequency counting. A full- function DMM, and more, doesn't have to cost over £169.95, If it's a Circuitmate DM800. Or, for a few dollars more, get true RMS (AC coupled) to let you accurately measure non-sinusoidal AC waveforms, and all the capability of die DM800, in the DM850. Of course, there's a whole range of Circuitmate DMMs and service test instru- ments, including the DM78 autoranger that DM2 5L Capacitance, Logic, hFE S89.95* DM850 True RMS i*h digits. DCV accuracy is .05% +3 digits TURN'S Frequency counter to gQOKHz Data Hold display capability Continuity beeper Built-in bail Anti-skid pads %*.j!M:. =3 Price: DM850 (True RMS). . . S219.95" DMB00 (Averagel SI 69,95- fits in a shirt pocket, yet gives you a full size 3 Vi digit, % " readout Not to mention a complete line of accessories like test leads, current clamps, even probes that can extend your DMMs range and sensitivity; All designed to work flawlessly with your Beckman Industrial Circuitmate DMM. See your Beckman Industrial distribu- tor and discover more DMM performance. For less. 'Sug^sred lisl price (JUS) Willi batlery, test leads and manual. In-Service Instruments, WeteThe Ok Ikfkmaii InduMriil torpurauon ln*irumtiilaiHMi I'mduri* Uiujmhi A SubtUtirf of Enu-fson Electric Cumfianv \9&\ Ruflin Rd . San [)il^>, Oljfnrnw*J2l2l IH l W (6W| *MM\* • fAK: (6l9)2fi&Ol72 • Ttf MflOJI CIRCLE 98 ON FREE INFORMATION CARD WHAT'S N EWS New instrument measures tape surface magnetism A new device that could lead to improved operation of many de- vices using magnetic tape has been developed by scientists at the Argon ne National Laboratory. The instrument, called a polar- ized-neutron reflectometer, uses neutrons to measure magnetic fields over microscopic depths at the surface of materials. "The instrument has already been used to measure the re- sponse of new recording materials to magnetic fields," says Cian Fletcher of Argonne. "Better infor- mation in this area could lead to improved magnetic recording technologies." "The trick," Fletcher said, "was to make the probe as sensitive as possible to magnetic fields at the surface. This was accomplished by sending the neutrons nearly paral- lel to the surface, so they graze it." The instrument can measure mag- netic fields within .0002-inch of the surface of the material. It can de- tect a magnetic field change over a distance as small as a billionth of an inch. GIAN P. FLETCHER, ARGONNE NATIONAL LABORATORY scientist, with the polarized-neutron reflectometer that could lead to improvements in magnetic recording. New infrared systems test gallium-arsenide wafers The National Bureau of Stan- dards reports two testing systems using polarized infrared light. They are expected to be especially useful in production control of gallium-arsenide (gAaS) wafers. GaAs applications are growing rapidly, but production of the near-perfect crystals needed for best performance is not as ad- vanced as with the older silicon technology. Detecting flaws in GaAs crystals should be easier with the new systems. One can scan an entire wafer; the other uses a 75- to 600- x microscope to view smaller portions. Both permit digital image storing and the use of false-color graphics to represent variations in characteristics that could point to potential problems. FCC abandons Consumer Radio Service The FCC reports that it "has de- clined to amend its rule to establish a Consumer Radio Ser- vice within the 462- and 467-MHz frequency segments now assigned to the General Mobile fiadio Service (CMRS)." That marks the end of an FCC-sponsored plan to replace the GMRS with a service that many felt would be of far-less value. Replies to a request for com- ments "failed to find any specific needs" for such a service, accord- ing to the FCC. Moreover, concern was expressed about the fate of present uses of the GMRS, includ- ing safety services provided by vol- unteer public service teams such as REACT (/fadio Emergency Associated Communications Teams). Consequently, the Commission concluded "that there was no rea- son to dislocate current GMRS users" and dropped the Consumer Radio Service concept. R-E Where's Your ELECTRONICS Career Headed? The Move You Make Today Can Shape Your Future Yes it's your move. Whether on a chess board or in your career, you should plan each move carefully. In electronics, you can move ahead faster and further with a B. S. DEGREE Put professional knowledge and a COLLEGE DEGREE in your electronics career. Earn your degree through independent study at home, with Grantham College of Engineering. No commuting to class. Study at your own pace, while continuing your present job. The accredited Grantham non-traditional degree program is intended for mature, fully employed workers who want to upgrade their careers . . . and who can successfully study electronics and supporting subjects through INDEPENDENT STUDY, AT HOME Free Details Available from; Grantham College of Engineering 10570 Humbolt Street Los Alamitos, California 90720 Independent Home Study Can Prepare You Study materials, carefully written by the Gran- tham staff for independent study at home, are supplied by the College, and your technical questions related to those materials and the lesson tests are promptly answered by the Gran- tham teaching staff. Recognition and Quality Assurance Grantham College of Engineering is accredited by the Accrediting Commission of the National Home Study Council. • All lessons and other study materials, as well as com- munications between the college and students, are in the English language. However, we have students in many foreign countries; about 80% of our students live in the United States of America. i 1 Grantham College of Engineering 10570 Humbolt Street, Los Alamitos, CA 90720 Pleose mail me your free catalog which explains your B.S. Degree independent-study program. Name. -Age_ Address. L^~ .State_ -Zip. > c £71 C o z o £T \~ O UJ _i ni 6 Q Video News DAVID LACHEETBRUCH, CONTRIBUTING EDITOR • TV Sets Large and. Small. TV sets with giant cathode- ray tubes are now included in many manufactures' lines; at the other end of the spectrum are the first active-matrix LCD color sets. Active-matrix LCDs produce a picture that is vastly superior in terms of resolution and color to the passive-matrix type used in the LCD sets introduced to date. Panasonic originally showed a sample of its 3- inch "Pocket Watch" LCD TV set almost a year ago, then shelved it because of manufacturing problems. Now it has been introduced in a somewhat different form— including stereo -FM/ AM radio (with headphones). Because of the inherent expense of producing the active-matrix LCD's, as well as the high value of the Japanese Yen m relation to the Dollar, Panasonic has put a list price of $550 on that little TV set. In addition, Toshiba plans to offer a 4-inch active-matrix LCD TV this 6ul, and has said it is "aiming" at a price of around $400. On the large screen front, several manufac- turers are introducing sets with screens larger than 26 or 27 Inches, but smaller than the 35- inch size produced initially by Mitsubishi, and later adopted by Sanyo, Sharp, Fisher, and Sears. Panasonic, in its new line, is featuring a 31- inch set, as is North American Philips, which manufactures sets under the Magnavox, Philco, and Sylvania brands, Now Toshiba, the originator of the FST (Flat, Square Tube), has introduced its FST Magnum, a tube that measures 30 inches, diagonally, and whose face is virtually flat. The rest of the industry is choosing up sides among the various sizes. Whichever they choose, the new types are luxuries indeed, with prices ranging from $2,000 and up. • Super Camcorder. The first combination camera-recorder capable of making home movies with higher resolution than broadcast TV or videodisc has been announced by Hitachi. Hitachi says it has developed an MOS camera pickup that can produce 450 lines of horizontal resolution, which it plans to mass-produce starting this summer. Until Hitachi's development became known, it was believed that camera pickups matching the resolution capability of the new Super-VHS system (Radio-Electronics, May, 1987 ) would be unavailable at a consumer price. Hitachi now says it will deliver a high-resolution Super-VHS camcorder this fall. RCA, whose VCR's and cameras are made by Hitachi, is expected to come out with a similar version. • Menu-Driven TV Sets.Television manufac- turers are borrowing from computers in providing what they see as the very latest in tuning convenience—the on-screen menu. That feature is carried to the furthest extreme in the new RCA and Magnavox lines, in which virtually every TV function may be tuned with on-screen indicators and legends. In RGA's Dimensia audio- video line even the FM- and AM -radio tuning is done on the TV screen, A typical TV tuning system gives on-screen indication of such functions as mono, stereo, SAP (for Second Audio Program), bass, treble, balance, input, brightness, picture, color, tint, sharpness, cable or broadcast tuning, on-off time setting, channel blockout (for parental control), and so forth. The Magnavox Total Remote Control system even has a novel "channel captioning" system. The user can identify each channel by its call letters or broadcast- or cable-network (HBO, CNN, etc.) affiliation, and airy tune that channel is displayed, the identification also is flashed on the screen. Double-Tuner TV sets. Another innovation in the new models is the two-tuner TV set. The first digital TV models, you'll recall, had the picture-in- picture feature that superimposes a second picture in a corner of the screen, but required a second picture source, such as a VCR, to use the feature. New color-TV sets from Sony and Hitachi get around that by incorporating two tuners. That allows the viewer to watch any two channels simultaneously, switch them around, halt one to a still picture, and so forth. Interestingly, the new double-tuner picture-in-picture storage system is digital, but other processing circuits are analog. And therein lies another trend in the new models: Use digital technology where necessary to provide a special feature; otherwise stay with tried-and-true analog circuitry. R-E TEST EQUIPMENT THAT MEASURES UP TO YOUR mr SPECIFICATIONS DMM-300 $79.95 3,5 DIGIT DMM / MULTITESTER Our besl model, A highly accurate, hi tion DMM loaded with many exrr .7 features Audible continuity, capacitance, transistor lorn pom lure at id conductance oil in one Hand - hold malar. Temperature probe, tost leads and battery included » Basic DC accuracy, plus or minus 0.26% « DC voitaqe 20Omv - 1000v. B ranges ■ AC voltage 200mv - 760v. 5 ranges • Resistance; 200 ohms — 2QM ohms. S ranges » AC/DC currant: 200uA — 10A„ G ranges - Capacitance: 200Qpf — 20ul 3 ranges * Transistor taster: hFE tost, NPN, PNP • Temperature taster 0° — ZDOO 4 F ■ Conductance 200ns * Fully over-load 1 protected ■ Input impedance. 10M ohm DMM-200 $40.95 3.5 DIGIT PULL FUNCTION DMM H*Qfo accuracy. 20 amp currant capability and many range sotting* make this model ideal for serious bench or fiftid wort Tilt stand lor tinnds-fTW upetaftun 2000 how u. with standard 9v Mil Probes and battery included - Buic DC accuracy: plus or minus • DC voltage 200mv - lOOOv, & rangas - AC voltage. 200rctv - 750v. b ranges • Resonance 200 ohms - 20M ohms. G ranges ■ AC DC current; 200uA - 20A. 6 ranges • Fully ovDf-loail protected • Input impedance: TOM ohm • 160 x 86 m 37mm. we+ghs 320 grams :jJ!Jt>H WJSTUUMENrs dmmtoo DMM-700 $49.95 DMM- 100 $29.95 3 5 DIGIT AUTORANGING DMM 3.5 DIGIT POCKET SIZE DMM Autornnge convenience or hilly manual oper- ation ScJoclBbUi LO OHM modo permits accurate >n cJffiuil resistance measurements involving tami conductor |uru;imns MEM mode for measurements relative to a specific reading Probe* and battery included. • Basic DC accuracy plus *>' minus 5% » DC voltage 20Qmv - lOOOv. autoranging or B manual ranges • AC voltage 2v — 7SOv outoran^wHi or 4 manual ranges • Resistance: 200 ohms - 20M ohm* autoranging - AC DC ciirrmii 20mA — 10 A. 2 ranges - Fully over-load ptotiDctud • Audible continuity taster • Inpcrf impedance: 10M ohm • 150 x 7& x 34mm. vvntghi 230 grams Shtnpocket portability with no compromise in features or accuracy- Large, easy to read 6" LCD display. 2000 hour battery Ida with standard Shy cofi provides over two yoars or" average use Probes and battery included. • Basic DC accuracy' plus or minus 0-6^ • DC voltage: 2v — lOOOv, 4 ranges • AC vottage: 200v — 75 0v. 2 ranges • Resistance: 2k ohm a - 2M ohms. 4 ranges • DC cunont 2mA — 2A. 4 ranges > iTvar-lood pr otectod • Input impedance- 1QM ohm • 1 30 k 75 x 2flmm. weighs 135 grams MODEL 2000 $349.95 20 MHz DUAL TRACE OSCILLOSCOPE Model 2000 combine* useful features and quality. Frequency calculation and phase measure mont are quick find easy in the X-Y Mode S^rvico technicians will appreciate the TV Sync circuitry to* viewing TV -V and TV-H as writ as accurate synchro™ uiton'of the Video Signal. Blanking Pedestals. VlTS and VerticEe' Horizontal sync pulses ■ Lab quality compensated 10X probes included * Built-in component tester * 110/220 Volt operation - X-Y operation * Bright 5" CRT * TV Sync filter MODEL 3500 $499.95 35 MHz DUAL TRACE OSCILLOSCOPE Wide bandwidth and exceptional 1 mvYDIV sensitivity make the Model 3500 a paworful diagnostic tool for engineers or technicians. Delayud triggering allows any portion of a waveform to be isolated and expanded for closer inspection Variable Holdcff makes possible the stable viewing of complex waveforms. ■ Lab quality compensated 10X probes included ■ Delayed and single sweep modes • Z Axis intensify modulation • X-Y operation » Bright &" CRT » TV Sync |,| m 0PM- 1000 $54.95 3.5 DIGIT PROBE TYPE DMM Autoranging, pert style design for the ultimate in portability and ease of use. Custom BO pin LSI chip increases reliability. Audible continurty tester and data hold feature for added convenience. Case, test leads and batteries included * Basic DC accuracy: plus or minus 1% * DC voltage; 2v — 500v, autoranging ■ AG voltagei Zv — &0Ov. autoranging * Resistance: 2k ohms — 2M ohms, autoranging * Fully over- load protected * Input Impedance: HMohm » 1 62 x 28 st 1 7mm. weighs 76 grams 2 YEAR WARRANTY ON ALL MODELS ' .^B. -^». [MasterCard - "^^^ *^^^" tfejDR INSTRUMENTS Si 110 Knowles Drive, Los Gatos, CA 95030 ORDER TOLL FREE 800-538-5000 (408) 866-6200 • FAX (408) 378-8927 • Telex 171-110 COPYRIGHT IMS JDR M1CRODEVICES THE JDR IMSTflUMENTS LOGO IS A REGISTERED TRADEMARK OF JDR MICHaOEVICES. JDR INSTRUMENTS IS * TRADEMARK OF JDR MICHODEVICES. OR VISIT OUR RETAIL STORE 1256 SOUTH BASCOM AVE. SAN JOSE, CA. (408) 947-8881 CIRCLE 59 ON FREE INFORMATION CARD Ask R-E WRITE TO: ASK R-E Radio-Electronics 500-B Bi-County Blvd. Farmingdale, NY 11735 w o z O UJ 6 Q < SUNRISE TO SUNSET SIMULATOR I need a sunrise/sunset simulator, which is a device that will turn on a lamp slowly to simulate the sun ris- ing and then, after a preset time, slowly dim the light to simulate sun- set. Do you have anything in your files?— D.E.R., Notre Dame, IN. Figure 1 shows a circuit that will fill the bill. The circuit was pre- sented by Jamieson Rowe and Kieth Woodward in the article "An Automatic Lamp Dimmer, Using the Triac AC Switch" in the maga- zine Electronics Australia, De- cember, 1966, pages 65-75. Be- cause the circuit was designed for 240-volt operation, some circuit values — those marked with an as- terisk — will have to be adjusted for operation on 117-volt powerlines. Current through a lamp or a heater load connected to socket SOI is controlled by varying the conduction period (angle) through each half-cycle of line voltage applied to the Triac (TR1), which is connected in series with the load across the AC powerline. The conduction period is varied and controlled by the unijunction Crystek Crystals FOR OPTIMUM STABILITY AND RELIABILITY IN FREQUENCY MANAGEMENT QUARTZ CRYSTALS FOR Industrial Equipment/Instrumentation Micro- process or control ' Computers/ Modems ' Test/Measurement " Medical General Communications Channel element Service (VHF/UHF) Land Mobile 2-way Marine Aircraft Telemetry ' Monitors/Scanners/Pagers ' Amateurs/2 -Meter/ Gen era I Coverage CB/Hobbiest/Experlmenter The Pulse of Dependable Communications Crystek Crystals Offers their new 16 page FREE catalog of crystals an oscillators. Ottering state of the art crystal components manufactuered by the latest automated technology. Custom designed or "off the shelf, 1 ' Crystek meets the need, worldwide. Write or C$11 today! CRYSTEK CORPORATION DIVISION OF WHITEHALL CORPORATION 2351/2371 Crystal Drive »Ft. Myers. FL 33907 P.O. Box 06135 «Ft. Myers, FL 33906-6135 TOLL FREE 1-800-237-3061 PH 81 3-936-21 09/TWX 510-951 -7448/ FAX 813-939-4226 TOLL FREE IN THE U.S.A. EXCEPT FLORIDA, ALASKA, HAWAII CIRCLE 193 ON FREE INFORMATION CARD transistor (Q3) circuit: a relaxation oscillator that is coupled to Triac TRVs gate through pulse trans- former T1. The oscillator's basic frequency depends on R7/C4. The bridge rectifier develops ap- proximately 165 volts peak, which is regulated to approximately 13.5 volts by silicon rectifiers D5 and D6 which are in series with 12-volt Zener diode D8. Also connected across the 13.5- volt source is Q3's RC timing net- work, R3/C2. For proper circuit op- eration, R3 must be adjusted so the voltage across C2 just rises to the conduction point of Q3 at the end of each half-cycle of the line voltage. Under that condition, Q3 delivers a current pulse through T1 to TRTs gate as the instantaneous line voltage drops close to zero. Since the line voltage is near zero, no appreciable current flows through the load (connected to SOI) when the Triac conducts. The adjustable dimming control R2, is a 10Kwi rewound potentiom- eter. The voltage tapped off R2 feeds an RC timing network con- sisting of R3 and rate control R4 in series with C3, a 100-|iF, 16-volt electrolytic capacitor. The voltage across C3 is applied to the base of a Darlington amplifier (Q1 and Q2) that uses 2N3565 or similar NPN silicon transistors. The Darling- ton's emitter output is connected to timing capacitor C4 and to the emitter of Q3. As C3 charges, its voltage is ap- plied as a "bootstrap" voltage to C4. Since the Triac is normally off, or nearly so, we simply cause it to turn on earlier and earlier in each half-cycle of the supply voltage when we want to increase current through the load that is connected to socket SOL On the other hand, the fourth law of robotics A robot shall make learning fun tor man and thereby improve the quality of life for mankind. '" y, * ii if IU. A robot is a robot is a robot... was a robot. Until HERO 2000. HERO 2000 is much more than a robot. It's a walking, talking 16- bit Computer. With 64K ROM and 24K RAM expandable to more than half megabyte. And a fully articulated arm with five 'axes of motion. Yours to program. Command. Modify and expand. Total system access and solderless experimenter boards provide almost limitless pos- sibilities. Its remote RF console with ASCII keyboard gives total control. Available with three self-study courses. Backed by Heath Company, world leader in electronic kits. Build your own HERO 2000. Or buy it assembled. Have fun learning skills that translate directly to the world of work. &L > a , 'i 1 AY tne 1-inouulecJpe builder M Heathkit * uibildiir) ol Zemin Elti'ranm CnpsrUMi "9 Name. Mail coupon today to receive a FREE Heathkit Catalog featuring HERO 2000. , Mall to: Heath Company Dept. 020-568 Benton Harbor, Michigan 49022 Address . City Zip- RO-141 CIRCLE 17B ON FREE INFORMATION CARD D2 APJ inv- OFF -VvW^ LI TRl&6£R TRANSFORMER FIG, 1 to reduce current through the load we dim control R2 to reduce the voltage across C3. That lowers the "bootstrap" voltage available for C4 so Q3 and TR1 begin con- ducting later and later in each half- cycle of the line voltage. When rate control R4 is 500K, the maximum fade-up and fade- down time is about 1 minute. Changing R4 to S megohms in- creases the control range to about 15 minutes. Pulse transformer T1 is wound on a 1-inch length of 3 /s-inch diam- eter ferrite rod. Each winding con- sists of 100 closewound turns of No. 36-40 enameled wire. Inductor L1 is a hash suppresser made of 50 closewound turns of No. 18 enameled wire on a 2-V-- inch piece of the same type of rod as used for the core of T1, Insulate the coil with plastic tape. Resistor R7 may have to be ad- justed slightly for correct circuit operation. R-E o o en H O UJ _i Lil 6 Q < EC 10 TEST INSTRUMENTS High Quality Lowest Prices Off-The-Shelf '&Jj( MINI-METERS w/MAXISPECS SCOPE 3V2 Digit LCD with 8 Full Functions $4495 $2995 Model DVM-632 Deluxe test leads included • 0.5% accuracy • Transistor gain test « Audible continuity checking & diode lest • 10 Amp measurement SCOPE 3V 2 Digit LCD Multimeter Model DVM-630 Test leads included • 0.5% accuracy • 6 functions, 19 ranges • Automatic zero adjust * Low battery indication • Measures 5" x 2%" x%" " B&K20 MHz Dual Trace s-bf $ 399 95 Probes included • 20 and 26 MHz band widths • TVV and TVH • X-Y operation • Trace rotation: adjustable front panel • Channel 1 output SCOPE 3 1 /2 Digit Capacitance Model $CC00 DCM-602 W^ Test leads included • 8 ranges with full scale values to 2000 uF • LSI circuit • Crystal time base • Frequency range 800 Hz to 8 Hz SCOPE 3Vz Digital Multimeters Model $7095 . DVM-638 T I*^ V Test leads included • 1 1 function, 38 f\ ranges • Logic level detector • Audibie "visual continuity • capacitance and conductance measurement. $5275 Model $C075 Wat DVM-636 30 Model DVM-634 * 7 'unction. 32 ranges ■ Transistor measurement Model DVM-636' * 8 function, 37 ranges • Capacitance measurement | SCOPE Pocket Sized Audio ■Kgnal Generator Model S4Q95 RC-555 ~* Test leads & 9V battery included • Low distortion sine-wave signal • 46 step selected frequency » xt range 20 Hz to 1 .5 KHz; x1 00 range 2KHz to 1 50 KHz HITACHI 35 MHz Dual Trace Oscillosco scilloscope $59995 Model V-355 (Reg. *899.95) Probes included » Thin, lightweight, compact • Large 6" rectangular, internal graticule CRT • Autofocus FORDHAM Sweep Function Generator Model FG-801 $04095 (Reg. =289.95) «■ l*J Test leads included • 7 frequency ranges, 0.2 Hz to 2 MHz • Accuracy to ±5% FORDHAM 550 MHz Frequency Counter $16995 ,#•'■" — •Qzgm Model FM-8 (Reg, *249.95) Completely assembled, p re-tested. preealibrated « High intensity 8-digit LED display | SCOPE 4V. Digit LCD Bench Digital Multimeter $19995 Model DVM-6005 Test lead sets 6 "D"size batteries included • 0,4" high characters • Conversion period: 500 milliseconds • Automatic, negative polarity »3C fTl Phcneorders accepted. ^ ^ CUA jT&g& tS&g Fordham ^ 800-645-9518 260 Motor Parkway, Hauppauge, NY 11788 In New York State 800-832-1446 Service & Shipping Charge Schedule Continental U.S.A. FOR ORDERS S25-100 . SI 01 250 sisisoo $501-750 ADD . $4.50 S6 00 $6.00 SI0 50 FOB ORDERS 5751-1.000.. S1.001-1500 SI ,501 -2,000 12.001 and up ADO $12.50 SIS SO (20.00 S250O NRI gives you two unbeatable opportunities for top pay, security, even a business of your own. Everybody wants to get ahead, but most people want assurance they're making the right job choice. According to the U.S. Department of Labor, jobs for electricians and air conditioning, heating and refrigera- tion technicians offer high earnings and good job prospects. Now NRI can show you how to go after the high earnings, the steady pay increases, even how to be your own boss in a business of your own. You'll get all the skills to get there. No night school, no need to quityour job until you're ready to make your move. NRI trains you right at home in your spare time. No Experience Needed. NRI starts you with the basics, then builds your knowledge and skill a step at a time, all the while adding practical know-how through hands-on training. You even get tools you need on the job or in a business of your own. Over a million and a half stu- dents have trained the NRI way since 1914. Be an Electrician. Each year, the demand for skilled construction, maintenance, commercial and utility electricians continues to grow. The LIS. Department of Labor estimates that close to 100,000 newjobs will open up in the next ten years -a conservative estimate compared to industry and union predictions. And few jobs can match the money-making potential of the qualified electrician. You can earn a salary in excess of $25,000 or be your own boss with your own electrical contracting business. Only NRI gives you this kind of practi- cal, job-oriented, hands-on training. You master practical skills like this with the equipment, test instruments, and training materials included in your course.. .you duplicate on-the-job wiring with your NRI Residential Wiring Practical Lab*.. .you leam professional troubleshooting using your Volt-Ohmmeier and Clamp-On Ammeter to test the circuits you build up on yourNRI Circuit Demonstrator... and, by installing and testing an electronic- programmable thermostat and a micropro- cessor- controlled remote power control, you come to understand today's electronics as it applies to the latest devices electri- cians are called on to install and repair. Training in the latest need-to-know electronics required of today's electrician. NRI created this new course so you can move from the simplest fundamentals of electricity, through professional wiring and trouble-shooting techniques, all the way up to mastering the practical field skills you need to become today's electronic-smart electrician. Be an electrician. It could be the best and last job choice you'll ever have to make. Be an Air Conditioning, Refrigeration, Heating Technician. When it comes to targeting the good paying jobs, regular pay increases, and the steady demand for your skills in this field, the U.S. Department of Labor scores a solid hit... high earnings and good job prospects attract many individuals. „ because people in business depend on their air conditioning, heating, and refrig- eration systems, the need for skilled tech- nicians to do maintenance work has to be met regardless of swings in the economy. Add millions of window units in older homes requiring maintenance and repair; heat pumps so popular they're now as common as furnaces; commercial refrigeration alone calling for skilled tech- nicians to install and service walk-in cool- ers, freezers, ice makers, and food cases. Wherever you look, there's tremendous opportunities for the trained air conditioning, refrigeration, and heating technician. NRI braining so complete, professional tools even included. NRI trains you for this lucrative field, gets you ready to land a good paying job, pick up extra income in your spare time, even start a business of your own. You're ready to jump right in because NRI includes the tools you need: system analyzer, leak detector, tubbing and joint tools, a top- quality vacuum pump for purging systems, plus demonstration panel units for hands- on systems training. Graduates of our Master Course also get optional free residential training at the world-famous York Institute in York, PA. Go after high earnings, pay increases, a business of your own. Send for NRI's free catalog. Find out what hands-on projects you do, the profes- sional tools you train with, and the future that can be yours. Act today. SEND COUPON TODAY FOR FREE NRI CATALOG.' 1 "■** — **%* Mf*9M ■ :■■ SCHOOLS McGraw-Hill Continuing Education Center 3S39 Wisconsin Avenue, NW, Washington. DC 20016 We'll ghr* you tomorrow, Ef CHECK ONE FREE CATALOG ONLY C Electrician D Air Conditioning Heating & Refrigeration □ Small Engine Repair □ Appliance Servicmg Q Locksmilhing & Eteclionic Security □ Building Construction For Career courses ipprnveti unta Gl bill |"l check tor details. D Automotive Servicing □ Bookkeeping & Accounting Q Photography □ Computer Electronics D Tv/AudioA/edeo Servicing P SaieHrte Electronics D Robotics & Industrial Conltols D Data Communications □ Industrial Electronics D Communication Electronics D ESearomc Design Technology D Telephone Servicing □ Digital Electronics Servicing D Basic Etecironics Rtraot Aije r.ity/RI3to/7ip L Accredited by til* National Home Study Council 4219-087 J > c o c en CO 00 -J 11 Letters LETTERS XAO/O - el ecTAo/v/cs, soo-a £/■ couNry souls, vard FARMINGDALE, A!Y //7-3S LEADER DMM/STORAGE OSCILLOSCOPE I was pleased to see Leader's model LCD-100 DMM/Storage Os- cilloscope (see Fig. 1) featured in a Radio-Electronics "Equipment Re- port" (June, 1987). While the re- view was informative, the pricing information was incorrect. The ac- tual price is $850.00, and the unit is currently available. MARC REINER Leader instruments Corp. 380 Oser Ave. Hauppauge, NY 11788 ON SOLDERING I enjoyed the article, "Solder- ing: Old Techniques and New DOES YOUR DIGITAL CAPACITANCE METER DO THIS? FULL 4 DIGIT 0,5 INCH LCD DISPLAY COMPLETELY AND THIS RANGE OF 0.0 pF to 1 FARAD (999.9 mF) 0.5% BASIC ACCURACY UP TO 100 uF AND THIS HEADS DIELECTRIC ABSORPTION AND THIS EXTENDED PSEUDO 5 DIGIT RESOLUTION ON SOME RANGES ONLY AND THIS ABILITY TO ZERO LARGE CAPACITANCE values up to m.n uF AND THIS CALCULATES TRUE CAPACITANCE IF CAPACITOR IS LEAKY AND THIS DIODE CLAMP AND FUSED FROTECTED INPUT. DISCHARGE RESISTOR IN OFF POSITION AT TERMINAL INPUTS. POWERED BY 9V BATTERY ONE YEAR PARTS S LABOUR WARRANTY FOR ONLY THIS JG WITH 10 HANGE MANUAL CAPABILITY AND THIS IDENTIFIES TRANSISTORS (NPN. FNP) AND THEIR LEADS (E, B. C, ETC.) AND THIS TESTS ZENEF DIODES AND RECTIFIERS. UP TO 20V 7.ENER WITH AC ADAPTOR, ZENEP, VOLTAGE WITH 9V BATTERY DEPENDS ON ITS CONDITION AND THIS AUTOMATICALLY CALCULATES LENGTHS OF CABLES IN FEET, METRES, MILES, KILOMETHES (THEORETICAL RANGE OF 9,999 MILESJ AND THIS ABILITY TO SORT CAPACITORS IN MANY DIFFERENT MODES AND THIS ABILITY TO READ LEAKY CAPACITANCE (INSULATION RESISTANCE OR CURRENT) AND THIS CALCULATES TIME CONSTANTS WITH USER DEFINED RESISTANCE VALUES AND THIS HOLD FUNCTION FREEZES DISPLAY SHIPPING INSTRUCTIONS: All unite shipped out F.O.B. Buffalo NY vis United Parcel Service (excepl Hawaii & Alaska) unless otherwise Indicated (In which case shipments will be F.O.B. Canada) CO o z o DC I- o LLI 6 Q < MC300 ^»- &DAETRON b division ol Bergeron Technologies Inc. 7666 KIMBEL STREET, UNIT 5 MISSISSAUGA. ONT.. CANADA LSS 1E9 (416)676-1600 PLEASE SEND ME U.S. FUNDS [QUANTITY) MC300(S) & S168.6S $ CARRYING CASE S 16.95 S ACAOAPTOR S 9.95 $ SHIPPING AN D HAN DUNG & S5. DO PE R INSTRU MEN T $ | JCHECK [ J MONEY ORDER S | ]VISA [ ] MASTERCARD TOTAL s [ ] CARD NO EXPIRY DATE SIGNATURE NAME AnnHFKS r.TTY STOTF 7IP CODF DEALER ENQUIRIES INVITED CIRCLE 200 ON FHEE INFORMATION CARD Technology," by Vaughan D. Mar- tin, in the May 1987 issue of Radio- Electronics. There should be more articles such as that, which give good data to the inexperienced. How else will they be able to learn? 1 would like to add two points: One is that we never use any sol- dering iron that isn't temperature- controlled for electronics solder- ing. The old "wood-burning" tools are history, but I didn't see any mention of temperature-con- trolled irons; they really aren't that expensive and are essential to good soldering. The second point is on tech- nique: The iron must always have an excess of solder in order for the heat to transfer quickly. Get on and get off the joint; otherwise, the heat will travel away from the joint and heat other areas. Under- standing heat flow, of course, is what soldering, brazing, and weld- ing are all about. A good rule of thumb would be to apply solder to the tip and joint simultaneously — making contact between the tip and the solder is very important. Keep up the good work. GERALD F. DULIN Torrance, CA ON PATENT APPLICATIONS I would like to thank David Pressman for his remarks con- cerning my article on patents, which appeared in the January, 1987 issue of Radio-Electronics. His corrections to details contained within the text illustrate the need for continuous monitoring of pat- ent requirements, and the wisdom of paying an attorney or an agent to at least review the application. 1 agree that the task of applying for a patent is not simple, and that 12 MODEL 9401 4 V? -digit, full function, hand -held DMM with .05% accuracy and data hold MODEL 9702 digi-clamp™ compact AC clamp-on volt-ohm- ammeter with data hold ELECTRONICS Division of Simpson Electric Company 859 Dundee Avenue, Elgin, IL 60120-3090 (312) 697-2265 • Telex 72-2416 Mercer Electronics products reflect the design and quality standards established by Simpson Electric Company, an industry leader for over 50 years and known worldwide for its integrity and product excellence. In Stock. . .Available Now! Stop in at your nearest distributor and see this new, complete line of Mercer test instruments. For the name of the MERCER distributor in your area, call (312) 697-2265, or send for our new line catalog. > c o c «5 CO ^1 CIRCLE 205 ON FREE INFORMATION CARD 13 CO o z o DC r- O LU < ir 14 the expression "relatively simple task" (the editor's words, inciden- tally) could mislead the reader. However, I think that the intent was to introduce the concept that applying for a patent is a finite task comprised of established pro- cedures, standard form, and a structured method of describing the invention. As to Mr. Arnold's letter con- cerning the water alarm: Back in 1975, I invented a wetness alarm that used the SCR circuit, and packaged the alarm in a plastic sandwich box. The alarm worked quite well, even after sitting under a hot-water heater for more than a year. In consideration of patenting the idea, I searched the archives of the Patent and Trademark Office and found numerous patents hav- ing to do with sensing water and actuating switches. In addition, I collected advertis- ing for a number of commercial enterprises marketing both water alarms and wetness-detection sys- ELENCO PRODUCTS AT DISCOUNT PRICES! iv-i-yf TWO 100MHz SWITCHABLE PROBES INCLUDED 20MHz DUAL TRACE OSCILLOSCOPE $359 M 0-1 251 35MHz DUAL TRACE OSCILLOSCOPE $498 MO- 1252 Top quality scopes at a very reasonable price. Contains all (he desired features. Elenco's 2 year guarantee assures you of continuous service. Two 1 x . 10 x probes, diagrams and manual Included. Write tor specs. MULTIMETER with CAPACITANCE AND TRANSISTOR TESTER Model CM-15O0A Reads Volts, Ohms, Current, Capacitors, Transistors £ Diodes Wilh case. $65 TRUE RMS *Vi DIGIT MULTIMETER Model M-7000 $135 .05% DC Accuracy .1 % Resistance with Freq. Counter S Deluxe Case GF-8016 FUNCTION GENERATOR .with Fret}. Counter $239 * Sine, Square, Triangle Pulse, Ramp. ,2to2MHi Frequency .1 thru 10MHz GF8015 without Freq. Meter $179 DIGITAL TRIPLE POWER SUPPLY Model XP-765 $195 ' 0-20V @ 1A 0-20V & 1A 5v @ 5A Fully Regulated, Short Circuit Protected with 2 Limit Conl. 3 Separate Supplies xp-650 with Analog Maters S159.50 DIGITAL 3 AMP POWER SUPPLY •^■^■mk Model XP-750 $165 0-40V 1.5A 0-20V @ 3A Fully regulated, short circuit protected current limit control XP-650 with Analog Meters $129.50 Auto Ranging plus Manual Ranging 3' .• Digit Meter 28 Functions Fully protected M-1180 .7% Acy S36.95 M-1182.25% Acy $39.95 M-1181 .1% Acv $42,95 10MHz OSCILLOSCOPE ,9 $199 Modal S-3000 ■ 10MHz DC or AC ■ Triggered Sweep ■ Calibrated Vert 4 Hor ■ Reads Volts A Freq DIGITAL LCR METER rwn $148 Model LC-1800 Measures: Inductors, Capacitors. Resistors BREADBOARD Model 9436 Shown 9430 1,100 pins S15 S434 2,170 pins $25 9436 2,860 pins $35 50MHI LOGIC PROBE 20 nsec with memory LP-7TJ0 MULTIFUNCTION COUNTERS 1 r mr! nfin"" '3E $245 Fioo CiCQ 1MMHI * IDS Frequency, Period, Totalize, Self Check with High- Stabilized Crystal Oven Oscillator, 8 Digit LED Display CSS SALES INC., 8744 W. North Ter., Nlles, IL 60648 ^ST [ fig 800-292- 7711 (312) 459-3040 ASK FOR CATALOG "™^ '^ 15 DAY MONEY BACK GUARANTEE 2 Year Limited Guarantee! Add 5% for Postage ($10 max), IL Res., 7% Tax CIRCLE 109 ON FREE INFORMATION CARD terns for industrial use. Although I did not come across a water alarm that used the SCR circuit, 1 con- cluded that a patent for a water alarm would not be profitable. I used the circuit as an example in the patenting article because it sat- isfied the need for a simple, easy- to-describe circuit, and yet one that exhibited a unique quality. DAVE SWEENEY TESTING SEMICONDUCTORS I was just reading "Testing Semi- conductors" in the April 1987 issue of Radio-Electronics. I enjoy read- ing your articles, because they re- fresh my memory on how various components work. In the article, you printed an er- ror that is very common in the field. In Fig. 1, you are measuring the reverse current of a diode using a microammeter (the text says milliameter). The reverse cur- rent through the diode should be extremely small as compared to the current used by the voltmeter (M2). With some voltmeters, that current is much higher than with others. It is a good practice, when measuring the properties of any device, to eliminate any external interference that you can. In the present case, simply placing the voltmeter before the current meter would quickly eliminate the problem. I find that many measurements in the field are inaccurate, due to the technicians involved not knowing how the test equipment affects the circuit that it's being connected to. I once witnessed a technician connecting a meter with a 600-ohm impedance to the input of a transmitter. That was done to measure the audio signal going into the transmitter. However, the meter was con- nected in parallel to the input, producing a 300-ohm impedance; therefore, the signal level was off by enough to indicate a problem with the transmitter, when, in fact, there was no problem — just an in- accurate measurement. RICHARD P. MORLEY APO, NY PC CLONE Thanks, Radio-Electronics: You finally printed an article, "IBM- continued on page 22 DESCRAMBLER ARTICLE PARTS February 1984 Issue We stock the parts, PC Board and AC Adaptor for an article on building a cable TV descrambler appearing in Radio-Electronics. #701 Parts Package* $29.00 Includes all the original resistors, capacitors, diodes, transistors, integrated circuits, coils, IF transformers (Toko BKAN-K5552AXX). #702 PC Board* $8.95 Original etched and drilled silk-screened PC Board used in the article. #704 AC Adaptor $7.95 Original (14 volts DC @ 285 ma) AC Adaptor used in the article. FREE reprint with Purchase Above #708 Toko Coil Set $6.95 Includes (2) BKAN-K5552AXX, (1) E520HN- 300023, (1) 144LY-120K and BFQ-85 Replacement 2SC2369. February 1987 Issue We stock the parts, PC Board and AC Adaptor for an article on a tri-mode cable TV desc ram bier appearing in Radio-Electronics. #301 Parts Package* $39.00 Includes ail the original resistors, capacitors, diodes, potentiometers, transistors, integrated circuits, LED's, Toko coil (E520HN-3000023) and Plessey Saw Filter (SY-323). #302 PC Board* $8.95 Original 5 x 8.8 etched and drilled silk- screened PC Board used in the article. #304 AC Adaptor $7.95 Original (14 to 18 volt DC @ 200 ma} AC Adaptor used in article. Free Reprint with Purchase Above #308 Plessey Si Toko Set $6.95 Includes (1 ) Plessey SY323 Saw Filter plus (1) Toko E520HN-300023 Coil. Add $2.50 Shipping & Handling; $4.50 Canadian Orders 72-CHANNEL MC-702 CONVERTER CABLE CONVERTER WITH INFRA-RED REMOTE CONTROL ib / y.yo Add $3.50 Shipping and Handling $4.50 on Canadian Orders • 72-channe! capability • Wireless. Infra-Red remote control • Channel output 2 or 3 switchable • Microprocessor controlled PLL operation • Skip channel memory eliminates unused channels • Parental control for all channels • Last channel recall • Fine tune memory • UL listed/FCC approved • Simple installation with any TV • Includes battery and 3 foot coax cable ORDER TOLL FREE 1-800-227-8529 Inside MA: 617-695-8699 VISA, MASTERCARD OR C.O.D. mama <£^> ■in - -. Mifalffl E HlflCllMW ■ *Not available to Massachusetts residents due to state law, €L€CTROfllCS,lflC. P.O. BOX 800 • MANSFIELD, MA 02048 «copyrighl 1987 by J&W Eleclronics. Inc. > C o c 15 CIRCLE 65 ON FREE INFORMATION CARD SPECIAL BUY ON VIDEO REWINDERS Saves Time And VCR Motor Wear! ASOLIDEX VCR AID! Free-Up Viewing Time that used to be spent rewinding tapes. And, take the work 1 oad' ' off yo ur V C R's moto r with th is f a etc ry new VHS Video Cassette Rewinder by Solidex®. Our special arrangement with the manufacturer makes it a great buy at a remarkably LOW liquidation price! 3 Big Benefits! This "must" device quickly rewinds video cassette tapes. Extends the life of your VCR's motor. And, helps you avoid costly VCR repairs. Buy NOW! And put this unit to work for you! • Reduces Costly Wear on VCR Motor. • Cuts Delays. Lets You Spend More Time Viewing Tapes, and Less Time Waiting on Rewinds. • Fast, Efficient Operation. Auto Shut-Off. Auto Soft Eject • Compact. Space-Saving Size: 2WH x 5"W x 11 WD. LED "On" Light. 1-Year Limited Factory Warranty Parts/Labor. Mfr. List $ 29.99 $ 19 Liquidation Priced At . Item H-2648-71 52-291 Ship, handling: $4.00 ea. Credil card customers can order by phone. 24 hours a day. 7 days a week- Toil-Free: 1-800-328-0609 L Sales oulside the 48 contiguous states are subject Id special conditions. Please call or write lo inquire. I SEND TO: Item H-2648 IHHfBn Direct Marketing Corp. 1105 Xenium Lane N/ Minneapolis, MN 5 S44 1-4494 I Send __ VHS Video Rewlnderjs) item H-264S-7152-291 at _ $19 each, plus $4 each lor ship, handling. (Minnesota | residents add 6% sales tax. Sony, no C.O.D. orders.) I n My check or money order is enclosed. (No delays in processing orders paid by check.) I PLEASE _ CHECK: i [B£| n EH D lsffi D in i l.U [ Q < -Exp- | PLEASE PRINT CLEARLY Name Address IOt« Apt It. Sign Here Equipment Reports Regency Informant Scanning Receiver An innovation in scanner technology SCANNERS HAVE NEVER BEEN POPULAR with John Q. Public. Potential scanner buffs are often intimi- dated by the task of programming a scanner's memory with frequen- cies of interest, or by the need to buy crystals for each frequency to be monitored. But the scanner in- dustry could be in forabig change and huge expansion if it follows the example set by the Informant INF-1, a new scanner from Regency Electronics (707 Records Street, In- dianapolis, IN 46226). The Informant promises to make just about everyone a scan- ner enthusiast because it's so easy to use — even first-time listeners will be hooked. The Informant is so different from other scanners because it's pre-programmed with all frequencies used by state and local police in each of the fifty states. Simply turn the scanner on, switch it to your state, and you're sure to hear lots of action. The Informant is so easy to use that it's almost possible to over- look its second impressive fea- ture: high-speed scanning. Thanks to what Regency calls TurboScan technology, the Informant offers a scanning rate of 40 channels per second. That's fast — most scanners on the market to- day offer a top scanning speed about one quarter of that. CIRCLE 37 ON FREE INFORMATION CARD Using the Informant How easy is it to use the Informant? With only two knobs and three toggle switches on the front panel, you know it can't be too difficult. One of the knobs, of course, is the volume control, which also serves as the power switch. The other is the squelch control. The hold switch is used to lock the scanner on a single frequency of interest. Pressing it once puts the scanner in the hold mode; pressing it a second time causes scanning to resume. The hiway/ city switch is used to select either state- police frequencies (hiway) or local city- and county-police fre- quencies (city). The third switch is the wx scan/state selector. When wx scan is selected, the Informant will scan the frequencies used by the National Weather Service to broadcast weather bulletins. The other position is used to select the state whose frequencies you want the Informant to scan. Rounding out thefrontpanelisa two-digit, vacuum-fluorescent dis- play that indicates the state and the type of signal (state, local, or weather) being monitored, and the scanner's mode. The Informant covers state, city, and county police frequencies from 36-47 MHz (VHF Low), 16 Satellite Electronics Training From NRI! Now you can move into borne satellite TV and commercial satellite communications with NRI's latest breakthrough in electronics training With NRI training, you'll explore every aspect of satellite transmission and reception as you assemble, install, troubleshoot, and train with the complete TVRO system included in your course. With today's satellite technology, a call to Paris is as dear and as easy to make as a call next door . . , executives use video conferencing to "meet" without leaving their offices . . . simultaneously, a billion people witness a single event (a soccer game, an inauguration, a benefit rock concert) . . . and scientists explore the mysteries of outer space without leaving their labs. These amazing applications of satellite technology have opened up exciting, new opportunities for the technician trained to install, maintain, troubleshoot, and repair satellite communications equipment. Explosive opportunities in home satellite TV In suburban backyards, alongside country farmhouses, and atop commercial buildings, satellite TV systems are continuing to expand all across the country. Already there are over a million TVRO (Television Receive-Only) systems in place in the U.S. alone, and experts predict that the future of home satellite TV looks even brighter. New jobs, new careers for the trained technician As an NRI-trained technician, you can concentrate on consumer-oriented TVRO equipment, or use your training to build a career servicing the satellite equipment that has become so vital in commercial and military communications to transmit and receive voice, data, and video signals. NRI brings satellite technology down to earth NRI trains you thoroughly in basic electronics, communications, and television principles. Using the remarkable NRI Discovery Lab® and your digital multimeter, you perform critical experiments, tests, and measurements. Then, using your NRI Antenna Applications and Design Lab, you assemble and test various types of antennas and matching sections. You then concentrate on both commercial and consumer satellite earth station equipment, putting theory to practice as you assemble, install, and test the complete satellite antenna system included in your course. Building your own home satellite TV system brings theory to life! Your Drake TVRO system comes complete with 6 ' parabolic dish antenna system, low-noise amplifier (LNA), down converter, receiver, low-loss coaxial cable, and even a permanent polar mount. By training with an actual TVRO system, you '11 come to understand, first-hand, the function and operation of a satellite earth station. And once completed, your TVRO system will provide the best television entertainment available — direct from the satellite to your home. Train the uniquely successful NRI way It's hands-on training, at home . . . designed around the latest state-of-the-art equipment. You discover by doing . . . and you do it at your own comfortable pace. Built into your NRI training is the enormous experience of our development specialists and instructors, whose training skills and personal guidance are available to you on a one-to-one basis. Make your move into the future today! Send tor your FREE NRI catalog Only NRI can train you at home for an exciting and rewarding career as a satellite electronics technician. And now is the time to act. Send today for your free, 100-page catalog. It details our training methods and materials, and our more than 72 years of successful innovation in hands-on career training. If the coupon is missing, write to: NRI Schools, 3939 Wisconsin Avenue, Washington, D.C. 20016. SCHOOLS McGraw-Hill Continuing Education Center 3939 Wisconsin Avenue, Washington, DC 20016 We'll give you tomorrow. V'CHECK ONE FREE CATALOG ONLY C Satellite Beetroniw □ Computer Electronics with Microcomputers n Robotics & Industrial Controls □ Video Electronics Servicing □ Electronic Design Tectinoktgy □ Digital Electronics m For Career courses approved under Gl bill. D check tor details. DOata Communications D Communications Electronics O industrial Electronics G Basic Electronics □ Telephone Servicing C Small Engine Servicing D Appliance Servicing C Automotive Servicing Q Air Conditioning, Heating. Refrigeration. & Solar Technology D Building Construction □ Locksmithing & Electronic Security □ Photography □ Bookkeeping Nome (Ptease Print) Ape I I TVRO SfStem and electronic tett equipment City/StaleiZIp Accredited By the Nalioml Home Study Council 10-087 I included with your training. I— — — — — — — ^— — — — — — — — — — ^^_— _^ > C o c CO CO 19 In our catalog you'll find over 450 interesting and useful items - from computer hardware and software to robots and test instruments, and from home security systems to color tv's and amateur radio equipment. But what makes Heath Company unique is that we offer you the confi- dence and pride that you can only get by building a state-of-the-art product yourself. And you're backed by our promise, "We won't let you fail." The Heathkit Catalog is a simple - and FREE - first step toward this ex- cellent opportunity. WO W for your FREE Heathkit Catalog CIRCLE 86 ON FREE INFORMATION CARD (65. / want to see what kitbuilding can do for me. Please send me the latest Heathkit Catalog Free, Send to: Heath Company, Dept. 020-562 Benton Harbor, Michigan 49022 Name 1 Address . A subsidiary ol Zenhh Electronics Corporation .Slale. Zlp — CL-7B7R2 150-163 MHz (VHF High), and 450-462 MHz (UHF). it's packaged in a case that will beat home in just about any car (about 1 1 /2x5x6y2 inches) and it comes equipped with a mobile mounting bracket. Also included are a DC power cord for permanent installation in a ve- hicle, and a cigarette-lighter plug for temporary installation. The Informant's simplicity is sure to be a great attraction to peo- ple who are unfamiliar with scan- ners, and to those who want an easy-to-use scanner for mobile use. But simplicity has its disad- vantages, too. Regency chose not to include a delay switch on the INF-1, probably to keep it looking as clean and simple as possible. Without a delay switch, the user has no control over how long the scanner will wait on a single fre- quency for the response to a trans- mission. The Informant waits less than a second, and in many cases that's just not long enough. The only other thing missing is a frequency display. In a sense, it's really not needed, but it would be nice to have some way to identify a given channel. Even though a lockout switch is not included, it is possible (by using two of the toggle switches in combination) to force the scanner to skip an unwanted channel. The Informant INF-1 sells for $369.95. We can't compare that price to any other scanner on the market because the Informant is unique. When its main features — TurboScan technology and simple operation — are incorporated in products built for the scanner hobbyist, things will never be the same. Regency is working on doing that now; by the time you read this, they will have intro- duced new scanners with features you've never even dreamed of. R-E New Lit ELECTRONICS PRODUCTS CATA- LOG, includes such items as a color light controller, color LED VU meter, electronic echo and re- verberation amplifier, stereo sim- ulator, multi-purpose melody gen- erator, digital clock with two timers, battery fluorescent light, infrared remote-control unit, speaker protection, superior elec- tronic roulette, power supply for microcomputer, and many others. 24 pages. Available on request from Mark V Electronics, Inc., 248 E. Main St., Suite 100, Alhambra, CA 91801. CIRCLE 38 ON FREE INFORMATION CARD CONSUMERS'S GUIDE TO PRI- MARY BATTERIES, is pocket-size {3Vi X 7 inch), six-page guide to the most-commonly used con- sumer batteries; also some un- usual types that are also available in the average supermarket — such as cylindrical, rectangular, and button/coin sizes. The booklet dis- cusses each type and how each should be used to assure the most efficiency and safety. It is available upon request from National Elec- trical Manufacturers Association, 2101 L Street N.W., Washington, DC 20037. CIRCLE 39 ON FREE INFORMATION CARD INTRODUCTION TO PACKET RA- DIO, is an 18-page, letter-sized booklet that explains packet's pro- cedures, operations, and applica- tions in easily-understood terms. It is written in a conversational style, and the contents are organized by the common ques- tions that most potential users ask about packet radio, such as: What is packet radio? Where is it used? What equipment do I need? How do I operate it? — and more. The booklet also includes FCC licens- ing information. It is available upon request from Kantronics, 1202 E. 23rd St., Lawrence, KS 66046. R-E CIRCLE 40 ON FREE INFORMATION CARD Now test and restore every CRT on the market . . . without ever buying another adaptor socket or coming up embarrassingly short in front of your customer ... or your money back with the new improved CR70 "BEAM BUILDER"™ Universal CRT Tester and Restorer Patented $995 Have you ever? Thrown away a good TV CRT, data display CRT, or scope CRT that could have been used for another two or three years because you had no way to test or restore it? Lost valuable customers because you advised them that they needed a new CRT when another technician came along and restored the CRT for them? Lost the profitable extra $35 or more that you could have gotten for restoring a CRT while on the job and locked in the profitable CRT sale later? Avoided handling profitable trade-ins or rentals because you were afraid you'd have to replace the picture tube when you could have restored it? Had a real need to test a CRT on the job, but didn't have the right adaptor socket or setup information in your setup book? If any of these things have happened to you, CALL TODAY, WATS FREE, 1-800-843-3338, for a FREE 15 day Self Demo. "BEAM BUILDER" it a trademark of Sencore, Inc. Call Today Wats Free 1-800-843-3338 3200 Sencore Drive Sioux Falls, SD 57107 innovatiuely designed 605-339-0100 In SD Only with your time in mind. CIRCLE 177 ON FREE INFORMATION CARD > C Q C TO CD ■^1 21 o z o EC h- o LU g < LETTERS continued from page 14 Compatible Clone Computer," (February I987 Computer Digest) that I can use and relate to. That one article, to me, is worth the three years or so that I have been carrying a subscription. I want to have a computer soon, and I think the article was my ticket to getting one. That is not to say that I have found the electronics articles useless. I subscribe to your maga- zine because I want to learn more and understand what's going on. I'm a mechanical-engineering stu- dent. My only connection to elec- tronics was a sorry two years that I spent learning printed-circuit art- work preparation from the ground up. You know — the "make a mis- take and we'll tell you what you did wrong" approach. I made a lot of mistakes. Anyone who's taped a PC art- Hands-on £*e*Y tJ\om ■ IF YOU'RE THE KIND OF READER that doesn't want to wait, you can order your next copy ot Hands-on Electronics now. Hands-on Electronics is crammed futl of electronic proj- ects that you won't be able to wait to build lor yourself. You can expect top-notch digital proj- ects, fun-to-play electronic games, valuable add-on computer projects, BCB and shortwave receivers, photographic dark room gadgets, de- vices to improve your car's performance, test equipment ideas, and more in every issue of Hands-on Electronics. ■ YOU CAN HAVE THE NEXT TWELVE IS- SUES of Hands-on Electronics delivered to your home for only $18.95 — saving $11.05 off the single copy price. ■ EVERY ISSUE OF Hands-on Electronics will continue to contain a variety of construction articles to suit every taste. In addition, feature articles on electronics fundamentals, test equip- ment and tools will round out each issue. Of course. Hands-on Electronics will continue to provide new product and literature listings to keep you up to date on the latest developments in electronic technology. ■ GET IN ON THE ACTION! Order your next issue of Hands-on Electronics today. Use the convenient order coupon below. Be sure to send check or money order — no cashl Hands-on Electronics SUBSCRIPTION I I I want lo be sure I doni miss any issues. Send me ONE FULL YEAR — iwelve issues — of Hands-on Electronics for $18.95 [Canada $23.95 U.S. Funds). D Payment Enclosed D Bill Me Later Please charge my □ Visa □ Mastercard Signature. Acct . # Exp. Date- Allow 6-8 weeks lor the first issue to arrive. Offer valid in U.S. Funds Only. Please print (Name) (Street Address) (City) (State) (Zip) Detach and mail today to: HANDS-ON ELECTRONICS SUBSCRIPTION DEPT. P.O. BOX 338 MOUNT MORRIS, IL 61054 ARE87 work, made the manufacturing drawing for the boardhouse, and drawn the component layout wants to get a more concrete feel- ing for electronics. Well, the next step is to stuff boards, get to know actual components, learn how to solder, etc. And then get into the theory as a final step. Radio-Electronics is giving me a library on those things, the "how to," and the advertisers for the parts and the tools. Again, thanks! And I also think that putting the magazine in a mailing wrapper is great — no more mangled covers. CURTIS E. VAILLETTE Madison, Wl ADDITIONAL INFORMATION In response to the question about operating 117-volt, 60-Hz equipment on 220-volt, SO Hz power lines that appeared in "Ask R-E" in Radio-Electronics, May 1987, here's some additional informa- tion. I was stationed overseas for four years; and as the staff Elec- tronics Officer, I did a lot of modi- fications of that type. Most manufacturers have kits that you can buy that compensate for the slower rotation speed of 60- Hz motors when operated on 50- Hz power. A different-size drive wheel is usually available for most turntables and tape recorders. A different-size pulley is usually available for motors that drive washers and dryers. Clock and timer modifications are available for 50 Hz, but are hardly worth the trouble. Buy a clock in the country where it' to be used. The timers on your washer, dryer, oven, etc. will run a little slower, but they can be set to com- pensate for that. The resistive load of oven, stove, iron, toaster, room-heater, and clothes-dryer heating elements will work well on either 60 or 50 Hz. Of course, the voltage must be correct. In a clothes dryer, you can modify the circuit to include a transformer on the drive motor and timer circuit. That will greatly reduce the size of the transformer that is needed. Forget about operating a TV set built for US video systems and 60 Hz: Rentorbuy one in the country 22 that you're in; modifications are too complicated to get into. Do not buy transformers in the U.S. to take overseas with you. There are always people being transferred back to the States or elsewhere, and who want to get rid of the transformers that they have. You can save a bundle. Even if you buy new ones, buy those wound to operate on 50 Hz; they have more iron in them and will operate cooler for a given load. Some people have one large transformer for the whole house; others have them for individual appliances. Whichever way you go, watch the load. Add up all the possible loads that you will have and get a transformer that's big enough to handle the job. If you buy equipment overseas, be sure that the adapters are avail- able to operate it when you get back to the U.S. Whatever you do for yourself or for somebody else, if you modify the equipment or change the wir- ing, be sure to document what you have done and what it was like be- fore you started. That will be a great help at some later date, for whomever tries to change it back once again. I've read your publications since 1 was age 12, and that was 60 years ago; I've been a subscriber for at least 30 years. ROY A. NORMAN Lcdr. U5N Ret. Brunswick, GA HEADLAMP WARNING On page 67 of the April 1987 is- sue of Radio-Etectranics a circuit is shown that warns of the head- lamps of a car being left on. If the voltage from the fuse panel used to power the piezobuzzer and LED is taken after the dimmer control for the panel lights, it is possible that there may not be enough volt- age to drive those components. When I built my own version of a warning circuit a few years ago, I used power from the parking lamps, which are not dimmed. Though it is unlikely that the car's fuse block will come after the dim- mer control, if that is the case, my solution is bound to work well. KEVIN STEBLETON Royal Oak, Ml R-E Walk "tough dog" troubles out of any TV & VCR in half the time ... or your money back with the exclusive, patented, VA62 Universal Video Analyzer . . .$3,295 Would you like to? Reduce analyzing time: Isolate any problem to one stage in any TV or VCR in minutes, without breaking a circuit connection, using the tried and proven signal substitution method of troubleshooting? Cut costly callbacks and increase customer referrals by completely performance testing TVs & VCRs before they leave your shop? Own the only analyzer that equips you to check all standard and cable channels with digital accuracy? Check complete, RF, IF, video and chroma response of any chassis in minutes without taking the back off the receiver or removing chassis plus set traps dynamically right on CRT too? Simplify alignment with exclusive nraltiburst pattern? Reduce costly inventory from stocking yokes, flybacks, and other coils and transformers, for substitution only, with the patented Ring- ing Test. Run dynamic proof positive test on any yoke, flyback, and inte- grated high voltage transformer ... in- or out-of-circuit? Protect your future by servicing VCRs for your customers before they go to your competition? Walk out "tough dog" troubles in any VCR chromi- nance or luminance circuit — stage-by- stage — to isolate problems in minutes? Have proof positive test of the video record/play heads before you replace the entire mechanism? Increase your business by meeting all TV and VCR manufacturers' requirements for profitable warranty service work with this one universally recommended analyzer? To prove it to yourself, CALL TODAY, WATS FREE, 1-800-843-3338, for a FREE Self Demo ... or learn how the VA62 works first by calling for your free simplified operation and application instruction guide, worth $10.00. Call Today Wats Free 1-800-843-3338 SErsJOOF=tE 3200 Sencore Drive Sioux Falls, SD 57107 605-339-0100 In SD Only innovatively designed with your time in mind. CIRCLE 178 ON FREE INFORMATION CARD > O c w 23 w o z o EC V- o LU _l 111 o D < VIDEO TAPE COPY PROTECTION GOT YOU DOWN? UNE ZAPPER VIDEO OUT 1 » STABILIZE YOUR PICTURE WITH THE NEW, IMPROVED LINE ZAPPER Bothered by brightness changes, vertical lumping and littering, and video noise? Tired of renting or buying tapes and being forced to watch an unstable washed out picture? Solve your problems with the Line Zap per. The Line Zapper accepts direct video from any VCR and monitors the signal, line by video line, When It sees the copy protection signal it Zaps it, giving you a nor- mal, clean signal at the output. Available in both kit form and fully assembled. The kit Is only $69.95 (Not recommended for the beginner) plus S3. 00 shipping. Assembled, tested unLis with a 90 day warranty are only J 1 24 95 plus $3. 00 shipping. Arizona residents must add 6.7% sales tax, Please allow 6 to 8 weeks for delivery- Dealer Inquiries welcome. ELEPHANT ELECTRONICS INC. BOX 41865-F PHOENIX, AZ 85080 (602) 581-1973 CIRCLE 120 ON FREE INFORMATION CARD EARN YOUR D.O.t.C ■ THROUGH HOME STUDY Our New and Highly Effective Advanced-Place- ment Program for experienced Electronic Tech- nicians grants credit for previous Schooling and Professional Experience, and can greatly re- duce the time required to complete Program and reach graduation. No residence schooling re- quired for qualified Eleelrontc Technicians. Through this Special Program you can pull all of the loose ends of your electronics background together and earn your B.S.E.E. Degree. Up- grade your status and pay to the Engineering Level. Advance Rapidly! Many finish in 12 months or less. Students and graduates in all 50 States and throughout the World. Established Over 40 Years! Write for free Descriptive Lit- erature. COOK'S INSTITUTE OF ELECTRONICS ENGINEERING ,_,__ 347 RAYMOND ROAD fejll P.O. BOX 20345 JACKSON, MISSISSIPPI 39209 New Products STATIC CONTROL, Screen Prep consists of two individual, dis- posable cloth pads sealed in twin foil packets. The first packet con- tains a premoistened pad satu- rated with a combination solvent/ anti-static agent that quickly re- moves dust, dirt, and fingerprint oils. The second packet contains a dry, lint-free pad to wipe the sur- face clear. action to remove the insulation with a slight pull. No sharp cutting edges are used, so there is com- plete freedom from cut or nicked wires. The light-weight handle is heat-insulated with cork. I CIRCLE 30 ON FREE INFORMATION CARD Screen Prep also provides a con- venient method for cleaning smudges and stains that result from equipment handling during service calls. It effectively removes CRT screen contaminants that in- hibit and destroy vision. Packaged in boxes of 24 dual-packs, Screen Prep is priced at $7.50 per box. — Chemtronics, 681 Old Willets Path, Hauppauge, NY 11788. THERMAL WIRE STRIPPER, the model C, features a continuously variable heat control that allows the unitto strip virtually any size or type of plastic-insulated wire. De- signed for production-line opera- tion, the device can be used either as a bench-operated tool or it can be held in the hand for use in inac- cessible locations. The stripper uses two parallel- heating elements to sever plastic insulation, and provides a pincers J i v • S CIRCLE 31 ON FREE INFORMATION CARD The model C strips any size down to the finest stranded #36 AWG wire without adjustment. It is also suited for coaxial cable and will strip Teflon as well materials with a lower melting point, such as vinyl, nylon, dacron, rayon, poly- ethylene, etc. It is priced at $139.50.— Western Electronic Prod- ucts Co., 107 Los Molinos, San Ctemente, CA 92672. POCKET MEGOHM METER, the Micro-Megger is a hand-held, bat- tery-powered megohm meter for CIRCLE 32 ON FREE INFORMATION CARD testing static dissipative and con- ductive materials. Featuring a se- 24 CIRCLE 194 ON FREE INFORMATION CARD ries of LED's that indicate surface resistivity, the unit performs over 1000 surface measurements on a single charge. The Micro-Megger measures surface electrical resistance in ac- cordance with ASTM D-257; it uses a rechargeable NiCad battery and presents no electrical shock haz- ard. It is priced at $249.00.— Charleswater Products, Inc., 93 Border St., West Newton, MA 02165. ODOMETER DATA COMPUTER, records and stores mileage, date, and time information for up to 60 trips before printing is required; it also keeps a year-to-year mileage total for the current and previous year, and calculates the percen- tage of auto use for business. It includes a detachable printer. CIRCLE 33 ON FREE INFORMATION CARD A simple hookup and command to the printer produces a printed record that can be submitted to the Internal Revenue Service. Each trip's printout includes a purpose section where business activities can be personalized. The compact computer, which is illuminated for use at night, can be placed anywhere in the vehicle, al- though the manufacturer recom- mends that such units be kept off dash due to temperature ex- tremes. The printer, which is powered off the computer, can be stored in the glove box, trunk, briefcase, oi the office when not in use. In addition, several people can share a printer. The Odometer Data Computer is priced at $399.00.— Mileage Val- idator, Inc., P.O. Box 830650, Richardson, TX 75083. R-E Exclusive, triple patented dynamic cap and coil analyzing . . . guaranteed to pinpoint your problem every time or your money back with the all new LC75 "Z METER 2" Capacitor Inductor Analyzer Patented $995 The "Z METER" is the only LC tester that enables you to test all capacitors and coils dynamically — plus, it's now faster, more accurate, and checks Equivalent Series Resistance {ESR) plus small wire high resistance coils. Eliminate expensive part substitution and time-consuming shotgun- ning with patented tests that give you results you can trust every time. Test capacitor value, leakage, dielectric absorption, and ESR dynamically; with up to 600 volts applied for guaranteed 100% reliable results — it's exclusive — it's triple patented. Save time and money with the only 100% reliable, in- or out-of-circuit inductor tester available. Dynamically test inductors for value, shorts, and opens, automatically under "dynamic" circuit conditions. Reduce costly parts inventory with patented tests you can trust. No more need to stock a large inventory of caps, coils, flybacks, and IHVTs. The "Z METER' 1 eliminates time-consuming and expensive parts substitut- ing with 100% reliable LC analyzing. Turn chaos into cash by quickly locating transmission line distance to opens and shorts to within feet, in any transmission line. Test troublesome SCRs & TRIACs easily and automatically without investing in an expensive second tester. The patented "Z METER 2" even tests SCRs, TRIACs, and High-Voltage Diodes dynamically with up to 600 volts applied by adding the new SCR250 SCR and TRIAC Test Accessory for only $148 or FREE OF CHARGE on Kick Off promotion. To try the world's only Dynamic LC Tester for yourself, CALL TODAY, WATS FREE, 1-800-843-3338, for a FREE 15 day Self Demo. Call Today Wats Free 1-800-843-3338 SENCORE 3200 Sencore Drive Sioux Falls, SD 57107 innovatively designed 605-339-0100 In SD Only with your time in mind. CIRCLE 179 ON FREE INFORMATION CARD > C Q C -i CO CD •vl 25 Communications Corner Diversity microphone transmission WE HAVE DEVOTED SEVERAL COLUMNS in the past to the subject of diver- sity reception as il pertains to high-frequency shortwave signals (to 30 MHz); those signals are par- ticularly sensitive to variations in polarization. Although we call the effects of polarization "selective fading," in fact the signal might not vary in strength at all; only its polarity varies. However, the typ- ical receiver sees a change in po- larization as being a change in signal strength. In the usual form of diversity re- ception, a special receiver switch- es between horizontal and vertical antennas, always selecting the an- tenna input that provides the max- imum signal strength. Naturally, a broad range of signal level is ac- cepted as "satisfactory" to prevent the antennas from switching back and forth continuously. But signal polarization isn't the only reception problem that re- quires diversity reception, nor does diversity reception neces- sarily require vertical and horizon- tal receiving antennas. In par- ticular, FM wireless microphones can be seriously affected by signal- phasing problems caused by mul- tipath reception. Although the problem can usually be resolved through diversity reception, the two antennas involved are both vertically polarized. For those of you unfamiliar with the wireless microphone, it is ac- tually a system consisting of a transmitter and a receiver. The CO o z o DC h- O ID _l LU o Q < DC 26 Fay Less For The Best Ufelter WTCPR Controlled Output Soldering Station $76.00 Universal Soldering Kit List S28.22 SALE $22.48 Includes dual heat soldering gun with 3 sobering ups, wrench, flux "brush, soldering aid tool & solder in plastic carrying case. 82CDPK Professional Soldering Kit List $33.29 SALE $30.50 Includes soldering gun with pre-tinned heavy copper tip. 2 sprue tips, wrench, llux brush, soldering aid tool S solder in plastic cartymg case. D550PK Y/>i>ifto Service Master ALeillK Roll Kit List S95.71 SALE $76.99 Includes 23 tools in plastic-coated canvas case: 6" long nose plior, 5" diagonal plier, 6" ad; ii stable wrench, regular and stubby handles, 9 regular nutovwers. 3 stubby nutdiivers, nos. t S 2 Phillips screwdnvers, ^16' & V4 T slotted screwdrivers, reamers and r extension. 99SM Weller Send now for your FREE catalog of electronic tools & test equipment ws JENKS & Son 1933 Montana Ave. NE Washington DC 20002 TOLL-FREE 1-800-638-6405 Floppy Drive Repair & Service Now the company that manufactures floppy drives has set up a repair division. Complete Floppy Drive service for the following: IBM TEAC Fujitsu Shugart Qume Apple Mitac Panasonic All repairs are warrantee*!! We also service on IBM and compatible computers. Call (408) 988-7510 for more information or bring your service needs to: First Street Computer Corp. 3385 Viso CL . Santa Clara, CA 95054 CIRCLE 188 ON FREE INFORMATION CARD CIRCLE 66 ON FREE INFORMATION CARD transmitter might be combined with the microphone into a micro- phone-shaped device, or the transmitter might be independent of the mike so it can be worn on a belt or concealed under the user's HV WIRELESS MICROPKPGNE WIRELESS RECEIVER FIG. 1 V. g REMOTE ANTENNA 180° DELAY RECEIVER ELECTRONIC SWITCH I I FIG. 2 clothes. Wireless mikes are used by those who prefer to roam unen- cumbered by the umbilical cord of a conventional microphone. Also, wireless sensors, which are usu- ally wireless-microphone based, are now built into electric instru- ments such as guitars so that per- formers can also dispense with the umbilical cord between instru- ment and amplifier. In principle, the wireless mikes are much like the inexpensive FM microphone kits you can buy from electronics hobby stores for a few dollars; those, of course, broad- cast a signal that can be received by a conventional FM radio. Pro- fessional wireless microphones, however, usually pack much more power, have a wider frequency re- sponse for high fidelity, and oper- ate on VHF frequencies specifical- ly assigned for stage, radio, and TV communications. Because they operate on VHF frequencies, they are prone to multipath reflections from by steel continued on page 31 Analyze defective waveforms faster, more accurately, and more confidently — every time or your money back with the SC61 Waveform Analyzer Patented $2,995 If you value your precious time, you will really want to check out what the exclusively patented SC61 Waveform Analyzer can do for you. 10 times faster, 10 times more accurate, with zero chance of error. End frustrating fiddling with confusing controls. Exclusive ultra solid ECL balanced noise cancelling sync amplifiers, simplified controls, and bright blue dual trace CRT help you measure signals to 100 MHz easier than ever. Accurately and confidently measure waveforms from a tiny 5 mV all the way to a whopping 3,000 V without hesitation with patented 3,000 VPP input protection — eliminates expensive "front end" repairs and costly equipment downtime. Make only one circuit connection and push one button for each circuit parameter test: You can instantly read out DC volts, peak-to-peak volts and frequency 100% automatically with digital speed and accuracy. It's a real troubleshooting confidence builder. Confidently analyze complex waveforms fast and easily. Exclusive Delta measurements let you intensify any waveform portion. Analyze glitches, interference signals, rise or fall times or voltage equivalents be- tween levels; direct in frequency or microseconds. Speed your digital logic circuit testing. Analyzing troublesome divide and multiply stages is quicker and error free — no time-consuming graticule counting or calculations. Simply connect one test lead to any test point, push a button, for test of your choice, for ERROR FREE results. To see what the SC61 can do for your troubleshooting personal productivity and analyzing confidence, CALL TODAY, WATS FREE, 1-800-843-3338, for a FREE 15 day Self Demo. Call Today Wats Free 1-800-843-3338 SENCORE 3200 Sencore Drive Sioux Falls, SD 57107 innovatively designed 605-339-0100 In SD Only with your time in mind. CIRCLE 180 ON FREE INFORMATION CARD > c c 3 27 Satellite TV Is HDTV the key to an international standard? BOB COOPER, JR., SATELLLITE TV EDITOR O z O □c H O LU Q < DC IN OUR LAST COLUMN WE DISCUSSED A plan to gradually phase out the 525-line NTSC national television standard. Its replacement would be a new wideband, High Definition TV (HDTV) system hav- ing more than 1,000 scanning lines. What makes the wideband plan feasible is the concept of sat- ellite distribution of television programming, which, perhaps, will ultimately replace terrestrial VHF and UHF transmitters. The most logical way to produce high-definition video is to double the picture bandwidth. If a 6-MHz bandwidth is required for 525-line NTSC video, a 12-MHz bandwidth will certainly accommodate 1,125- line video. But it's impossible to allow all existing television sta- tions to increase their bandwidth within the existing VHF and UHF television spectrum because the spectrum is essentially filled to ca- pacity already. Also, the FCC has E3L3ECTE0WICS JTJBI1EE fl MEMPHIS, T3EHK1SSEE 1987 National Professional Electronics Convention NESDA [Inc. NATESA). I5C6T £ TESDA ON THE MISSISSIPPI RIVER The Peabody • Memphis, TN August 1Q-' 1_ 1-15, 1987 W BPJH .1 • 5-oclrf E Will • SpoftKwwi H • TflChnbtiJ $*min«-i • Buil n wi Hm mw iH Tralnlfif • T#o-D»r W(+lofiri Prcftftlonal EWtronin Trad* Show • Mtrd lirtnd * EWala Itrwl * Th* Mlnlnlpvpi Bhif TENTA TlVE SCHEDULE MONDAY, AUGUST 10 • Go: i & icnnii Quiinps * Beg.*i 40-hrxjp < iis-i u = ton Contefenct and btfic VCR «r. vicmg COvrw « G«E-«Cqualm£tl fM'iy *nd UiiiLuippi River Chmi fid* {free loafly r*Qinrimi: axtra-cQir option lo olrwrih TUESDAY d AUGU5Tll • \r.iuucia'i!VCH KhCtf *Bux»rtftt mjridgerrwm wrniriar • Technical Hrninart * LSC'ET Ofi*»f •l*ClnW* » Otrintr pjj(v WEDNESDAY, AUGUST 1 2 • Instructor^ VCR KrhOol • INES-DAm- nu*l Hauii o1 R(pjeMniiiivei ind jmmbir- thip mailing/Stale ol the AUOCiaiioPi * Ttchn-cal irm.nan ■DiAAlf jMriy. THURSDAY, AUGUST 13 * Inwueipri/VCR tChBQl * T i Jde Shavu » NESD A ffilicsr tltclhonf * Technical iem' ■nan ■ C d u m r ¥■■' Wr a l c m dirinaj party. FRIDAY, AUGUST M * IminJCtoru'VCn tChoOl *De«i»rJ l MM (Tien! 1 1 n m ■ Nanorval Sarvice Corvlarencc ■ CET £x*mt "Com- ISCET iniu*! rtiwiifig * PtQiirttiQTtwi MmtrorS ■ Dmn«r parly. SATURDAY. AUGUST 1 S * ISC FJT ur rati j.-i: • IrnT.ructorir'VCR Khpol • Advancpii VCR kjv«;c itrnSQl # Scru.Cing Dipta! VCRi • NESDA7I5CET annual award* Lwrtqu** vidollicirs ■miail^ilDn cam moiiy . For more information and a registration form, contact NPEC '87, 2708 W. Berry St., Ft. Worth TX 76109; Ph. (817) 921 9061 Try the I EleclroniGS bulletin board system (RE-BBS) 516-293-2283 The more you use tl !be mare useful il becomes, We support 300 and 1200 baud operation, Paramelers 0N1 (8 data tails, no partly. 1 stop bit) or 7E1 (7 data bits, even partly, 1 Slop Lull Add yourself to our user hies to Increase your access Communicate with other R.-E readers Leave your comments on R-E With the 5YSQP RE-BBS 516-293-2283 FIG. 1 been chipping away at both the top end (channels 70-82) and the bottom end (channels 14-20) of the UHF band for more than a decade, siphoning off UHF channels for two-way radio and other uses. Out of spectrum Spectrum space is, in fact, al- most non-existent until the micro- wave region near 12 GHz. There, perhaps with careful planning, is the means whereby we can fit in the wide bandwidths required for HDTV. CBS would like to see ter- 28 INTERESTED IN SCRAMBLING? Bob Cooper's CSD Magazine maintains a 24 hour per day Scramble- Fax-Hotline telephone service (305/771- 0575) which you may cat! to obtain a 3- minute recorded update on the latest hap- penings in the satellite scrambling world, Scramble- Fax Newsletter is also pub- lished to keep you abreast of the latest events in descrambltng, including sources for descrambling chips and equipment. For information, write Scramble Fax, P.O. Box 100858. Ft. Lauderdale, FL. 33310 or telephone 305-771-0505. If you have a dish of your own, tune in the Caribbean Super Station (Western 5, transponder 23) Tuesdays at 7 PM east- ern for a special weekly Bob Cooper re- port. Also tune-in Boresight at 9 PM Thursday nights (Spacenet 1, transpon- der 9) for a weekly one- hour report on the activities in the home TVRO field. restrial delivery of HDTV signals, meaning that the signals originate from a microwave transmitting an- tenna mounted on a tall tower or a tall building. Virtually nobody else likes that concept because trans- mission ranges would be short (typically, only direct line of sight — under 25 miles). Most favor a satellite-to-home approach, using the DBS-assigned 500-MHz bandwidth between 12.2 and 12.7 GHz. A few engineers are looking at the next higher satellite band, Ka, in the 20-CHz region, because precise beam shaping would allow footprint-patterned satellite trans- mitting antennas to cover irregular shapes (such as the state of New Jersey) with great accuracy. It's assumed that the U.S. will make the decision to implement HDTV before 1990 because that's the year that the Japanese expect to launch a fully operational three- channel HDTV satellite (in the 12 GHz-band). Already, new satellite receivers, television monitors, and videotape decks have been designed to support their HDTV program. When the Japanese inau- gurate the HDTV service they plan to have all of the consumer receiv- ing equipment on store shelves ready for delivery. The revolution at the receiving end, while spectacular, is hardly the full effort. To produce HDTV broadcasts, entirely new studio and transmission equipment and programming had to be created, because in addition to the en- hanced resolution, the aspect ratio (width to height) was changed as well : from 4 x 3 to 5 x 3. (Sony began delivering 5x3 HDTV cameras and professional tape decks late in 1986, and new production studios using that equipment are already operating in several US cities.) Back-door standards Although HDTV addresses itself to a better-quality picture, in actu- al fact it is interlocked with the concept of a global TV standard, and for many communications people the idea of a global TV stan- dard is more important than whether the TV screen can show greater picture detail. But the idea of a high-resolution picture has more sizzle and snap than tech- nical standards — about which the average user couldn't care two hoots — so we will most probably continued on page 74 CIRCLE 1QS ON FREE INFORMATION CARD SINCE 1962 THE MOST POPULAR WIRE-WOUND CB ANTENNAS IN THE WORLD Because. . . they perform FACT "When C8 was legalized in England. 'FirBstik' antennas were barred from sale becajse the emitted signal was too strong. Fortunately, no other country, including the U.S., limits antenna efficiency." YOU CAN HAVE SECOND BEST OR, Tirestik'! Call or Write for FREE Catalog 'Firestik' Antenna Company 2614 East Adams Phoenix, Arizona 85034 (602) 273-7151 MILLIONS OF SATISFIED OWNERS CIRCLE 100 ON FREE INFORMATION CARD Be an FCC LICENSED ELECTRONIC TECHNICIAN! Earn up to S30 an hour and more! Learn at home in spare time. No previous experience needed. ui. mi No costly school. No commuting to class. The Original Home-Study course pre- pares you for the "FCC Commercial Radio- telephone License". This valuable license is your "ticket" Lo thousands of exciting jobs in Communications. Radio-TV, Micro- wave. Computers, Radar, Avonics and more! You don't need a college degree to qualify, but you do need an FCC License. No Need to Quit Your Job or Go To School This proven course is easy, fast and low cost! GUARANTEED PASS - You get your FCC License or money refunded. Send tor FREE facts now. MAIL COUPON TODAY! r VdmrriiiiiDVRc¥uCTionV""I > FCC LICENSE TRAINING, Dept 90 I £ P.O. Box 2223, San Francisco, CA 94126 [ Jjf Please rush FREE details immediately I I ^ ADDRESS 1 1 to OITV RT4TF 71 P >J 29 designer's Notebook Logic-farnily translation ROBERT GROSSBLATT, CIRCUITS EDITOR in O •z. o 5 6 □ < cc EVERYBODY HAS HIS FAVORITE LOGIC family. Some like the familiarity of TTL and have never given CMOS a chance since the bad days of the CMOS "A" series devices. On the other hand, some like CMOS and think that anyone hung up on TTL is from the stone age. DTL and RTL users are primarily history. The truth of the matter is that both TTL and CMOS are going to be around for a while because each has advantages and disadvan- tages. If you look at enough sche- matics, you'll see that many circuit designers routinely mix both logic families in the same electronics package. There are several considerations to keep in mind if you want to do the same thing in your own de- signs. Mixing logic families re- quires that you pay attention to the voltage at which they change state. TTL parts have much stricter re- quirements than CMOS. A TTL low state has a maximum voltage of about 0.8, and a TTL high state has a minimum voltage of 2.4. CMOS, on the other hand, is much more flexible. A low is usually defined as less than half the supply voltage, and a high is more than half the supply voltage. If you're working with a five- volt-only circuit, mixing TTL and CMOS is simple. As you can see in Fig. 1-a, driving a single TTL input with a CMOS output requires nothing more than connecting the two parts together. Going from TTL to CMOS, however, requires a bit more thought. Assuming a five- volt supply, the TTL high output can be as low as 2.4 volts. That's slightly below the point at which +5V INPUT < ) OUTPUT FIG.I INPUT O CMOS -•-+10V the CMOS input will change state, so there's no guarantee that the circuit will work correctly. The so- lution is to add a pull-up resistor of about 4.7K, as shown in Fig. 1-6. The exact value of the resistor de- pends on the type of TTL you're using (74, 74S, 74LS, etc.), but a value of 4. 7K at least will get you in the ballpark. Different supply voltages Things get even more tricky if the CMOS and TTL halves of your circuit are powered by different voltages. Two readily available CMOS buffers (the 4049 and the 4050) can translate the higher-volt- age CMOS output into something the TTL input can use. A sample circuit is shown in Fig. 2-a. To make the translation without in- verting the signal, use a 4050. Going from TTL at 5 volts to CMOS at, say, 10 volts, requires some voltage translation. We can't always do it the way we did in Fig. 1-6 because the TTL output must be isolated from the higher CMOS voltage. There are many schemes to get the job done, but an easy one is shown in Fig. 2-6. A small-signal NPN transistor is used as a buffer- ing switch between the TTL and the CMOS parts, but keep in mind that the transistor will invert the signal from the TTL output. You can re-invert the signal by using another transistor or a spare CMOS gate. Fanout Before we leave the subject of logic-family translation, we must talk about fanout. If you're a reg- ular CMOS user, you're probably used to ignoring fanout limits al- together. The reason is that the in- put impedance of a typical CMOS part is so high that you can drive as many inputs as you want with a single output. The same is true when driving CMOS with TTL: A typical TTL output has more than enough current-capacity to drive any number of CMOS inputs. 30 Going the other way, however, is a bit of a problem. The reason is that most CMOS outputs simply can't deliver much current into a low-impedance TTL input. The number of TTL inputs you can drive with a CMOS output depends on the specific TTL part you're using. As a general rule you can drive more LS inputs than reg- ular or S inputs, but it's usually better to be safe than sorry. So don't drive more than two inputs, regardless of type. As a matter of fact, it's better not to drive more than one, and make it a 7404 or 74S04. You'll have no trouble what- soever driving the single input and then following the standard rules for TTL-to-TTL fanout. If you anticipate designing many mixed-family logic circuits, work out each problem on a breadboard and standardize the design. By doing so, any time you're faced with the same problem, you'll have a debugged module you can drop in your circuit and solve the problem. And that will let you go on to more important things. R-E COMMUNICATIONS CORNER continued from page 27 beams, stage hardware, and any- thing else that can reflect radio sig- nals. As shown in Fig. 1, any re- flected signals arrive at a wireless- microphone system's receiving an- tenna after a directly received one; hence, they are usually out of phase with the directly received signal. That phase difference can plunge the received signal level right into the noise level. As a re- sult, at one moment the audience may hear the performer, but at the next only the lips are seen moving. That's because, when the signal strength is too low, the micro- phone's receiver squelches to pre- vent the listener's ears from possibly being assaulted by the sound of random noise. Curing multiphase distortion Multipath distortion plagued wireless-microphone communica- tions until the introduction of a diversity antenna/receiver system that Shure {222 Hartrey Ave., Evan- ston, IL 60202), a manufacturer of high-performance microphone equipment, calls Diversiphase. The wonder of Diversiphase is that it wasn't invented earlier. Fig- ure 2 shows how it works. The sig- nal is received by vertical antennas a and b, which feed the receiver in parallel. To ensure that both an- tennas aren't affected by the same multipath signals, at least one an- tenna must be remotely located. Usually, 25-foot spacing between theantennas is best; the minimum spacing is 6 feet. However, note that antenna a feeds the receiver directly, where- as antenna b feeds the receiver through a 180° delay line that is by- passed by an electronic switch. The delay line is a half-wavelength (at the operating frequency) coax- ial section. The signals from the two anten- nas always add together, so that when they are in-phase, the total signal delivered to the receiver is 3 continued on page 78 B^S op" Q\ MODEL STARCOM-460 T-»-- ^ m &&> $QQ95 JERROLD CORDLESS CABLE TV CONVERTERS I I I I I I I n Volume control 63 channels Mute control Auto malic fins Inning ANY QUANTITY instant channel recall Programmable lo go on at a particular channel and off automatically Compaiible with descram biers JERROLD CORDLESS CABLE TV CONVERTER MODEL DRX3-105/400 $ 69 95 SB channels Remote channel changing Remote on/off swilch Remote fine tuning JERROLD CORDLESS CABLE TV CONVERTER _:* MODEL DRZ/450 • 66 channels • Automatic fine tunln ■ A/B swilch option I ■ \ I II $69.95/ S79.95 ea JERROLD CORDED CABLE TV CONVERTER MODEL JRX3-105 CjJOH'oi/O/ 10 up S39 .95/6-9 $49.95/1-5 , THE RABBIT VIDEO MULTIPLYING SYSTEM TR-7000 S59.95/6-11 $69.96/1-5 IT'S LIKE HAVING A VCR III EVERY ROOM MASTER CARD I VISA OM NITRON ELECTRONICS 770 Amsterdam Ave., New York, NY 10025 SHIPPING CHARGES For Ordeis Add t $25-100 $6.50 E $100-500 S8.50 . $500-750 $1050 $750 and up $2000 CIRCLE 1 1 ON FREE INFORMATION CARD > C Q C CD to CO --I 31 Audio Update The audio answerman LARRY KLEIN, AUDIO EDITOR IT OCCURRED TO ME RECENTLY THAT I've been answering consumers' hi-fi questions in various publica- tions for about 30 years! Of course, as times have changed and electronics has advanced, the nature of those questions has also evolved. In 1964, for example, I cautioned a reader that a metal 6L6 tube was not an adequate replace- ment for a 6L6GC because the glass CC tube was designed to withstand the higher voltages to be encountered in the new audio amplifiers. Over the years I've handled problems of stereo and then quad- raphonic conversion, advised on the pros and cons of switching to transistor equipment, and so forth. Today those questions and their answers are no longer perti- nent, but new queries have arisen to take their place, so I've as- sembled a group of today's recur- rent Q's and A's in hope that they will be of some aid and comfort both to the novice and to the tech- nically beleaguered audiophile. On-off switching Q Should audio equipment • be left on permanently? borne audiophiles and manufac- turers claim that there is less wear on the equipment if it is left on, and that it also sounds better. A Several manufacturers of . preamps and accessories z advise that their equipment be § switched on permanently. In fact, o some equipment is designed so £j that its circuits are powered at re- ^ duced voltage even when switch- 5 ed off, as long as the AC line cord is !r plugged in. The purpose in both 32 cases is simply to prevent audio thumps and other noises as the circuits charge at the moment of turn-on. When dealing with vac- uum tubes there's an additional reason not to have the equipment fully off. Tube filaments (like elec- tric light bulbs) tend to suffer stress from turn-on surges. If a tube is always on (with reduced filament voltage), thermal shock is reduced, and the tube's filament life is extended. Aside from noise and longevity, some manufacturers claim that there is a sonic advantage in hav- ing their equipment constantly on. That may be, but my feeling is that any design that needs to be permanently powered to avoid a long warm-up drift needs to be gotten back to the drawing board as quickly as possible! In any case, most manufacturers would advise you to turn off your audio equip- ment when you don't plan to use it again for several hours. Separate speakers Ql have been told that you . should use one type of speaker for classical records and another for rock. Do you agree with that idea? A Absolutely not! Every speak- • er system should deliver an accurate acoustic analog of the electrical signal provided to it by the amplifier. Those pushing the concept of different speakers for different music are saying, in effect, that certain types of music sound best with speakers whose frequency-response curves, dis- persion, distortion levels, etc. de- viate from the ideal. It seems to me that if each musi- cal instrument in a band or or- chestra has been recorded with a specific loudness level relative to the other instruments in that band or orchestra, you want your speak- ers to reproduce those levels accu- rately, no matter what kind of music is involved. For example, if the recording has been engi- neered so that the brass has an extra "nasal" quality, the bass extra "sock," and the string extra "bite," a speaker with a flat response will deliver those qualities — neither more nor less. In other words, you want a speaker system that is neu- tral, rather than having a specific built-in tonal quality. When a speaker system injects its own to- nal qualities — such as an upper- mid range boost — into the music, some program material may sound "better" — but on most program material the contribution will be inappropriate and will only be heard as coloration. I can see a situation in which a speaker that does a fine job of re- producing string quartets is not suitable for rock, but only because it lacks the acoustic-output ca- pability to achieve the desired sound-pressure levels. Achieving an adequate loudness level for rock or contemporary electronic music can drive your amplifier, your speakers, or both into distor- tion. The distortion may be due to (1) inadequate amplifier power, low speaker efficiency, or both, or (2) inadequate power-handling ca- pacity on the part of the speakers. In such a case, other speakers with greater efficiency and power-han- dling capacity would, of course, do a better job. However, all other performance criteria in respect to frequency range and smoothness, distortion, dispersion, etc., con- tinue to be valid. For that reason, a speaker that can deliver the high volume levels desirable for rock reproduction, if it is in truth a high-fidelity re- producer, should do just as good a job reproducing the more moder- ate levels of a string quartet. Tape-dub overload QWhen I dub some of my • records onto cassette, sec- tions of the tape (usually at the beginning) suffer from a sort of breakup in the sound every sec- ond or so. When I listen to the disks themselves during dubbing or later, they sound fine. What's wrong? A The records you are trying to ■ dub are probably warped sufficiently to cause severe vertical deflection of your phono stylus during play. That produces a very strong, very low frequency signal that overloads your tape (or cas- sette) deck's electronics. The rec- ords themselves sound fine when heard through your system proba- bly because the subsonic warp sig- nal is either handled without overload or it is filtered out by components following the tape- output jack in your equipment. You can test my hypothesis by playing the problem disks again and noting whether warps dis- place the phono stylus toward the cartridge body and whether the warps coincide with the taped overload distortion. Dubbing Dolby QWhen copying a Dolby-en- • coded tape from one deck to another, is it better to decode the tape playing on deck A and re- encode it when recording on deck B, or to record the tape from deck A to deck B without decoding and re-encoding? A You'll achieve the best re- • suits in duplicating Dolby- processed tapes if you decode the signal during playback and re-en- code it while copying. In other words, the Dolby circuits should be switched on in both machines. If you were to copy Dolby-pro- cessed audio material with the de- coding and encoding circuits switched off, the signal is likely to be recorded by the second ma- chine at a different level than on the original tape. That can confuse the Dolby-decoding circuits dur- ing playback of the copied tape because the Dolby reference level has been shifted. The result will be less noise reduction and some high-frequency boost (or loss) in playback of low-level signals. Power and volume loss Q Although I have a CD play- ■ er, I need a record player tor my 10-year collection of LP's. I recently replaced my old phono cartridge with a new high-quality unit, but now the power fed to my speakers is much lower on phono than on tape or tuner. Exactly what is the problem? A Variations on that question . have appeared in my mail at least twice a' month for many years. The problem — and it really isn't a problem — is a loss (or a gain) in volume resulting from a change in equipment: phono car- tridge, tape deck, CD player, tuner, preamplifier, power ampli- fier — in fact, any component. The "problem" arises partially because many audiophiles mis- takenly believe that volume con- trol setting correlates directly with amplifier output power. It does nor.' Think of an amplifier's volume control as a handle on a water faucet. If the water pressure (sig- nal voltage) is very high, then a slight twist will deliver a high vol- ume of water (sound); if the pres- sure is lower, then the faucet has to be opened further to get the same volume of water flowing from it. In the case in point, the new phono cartridge obviously delivers less signal to the preamplifier for a given record-groove velocity than the previous model. To determine whether the out- put level of a phono cartridge is adequate, play a record at the loudest volume at which you would ever normally listen to it, and then, without touching the volume control, lift the tone arm with its cue control. Listen for noise from the phono-preamp stages. If you don't hear hum, hiss, or RF buzz, phono gain is within the proper range. R-E "Made in U.S.A." JHN I Since I 1965 I We've been supplying quality crystals since 1965 — long before the flood of cheap imports. We're still supplying quality crystals with • Quick Turnaround • Low Price • High Quality TO SOLVE CRYSTAL PROBLEMS, GET THIS CATALOG JAN CRYSTALS P.O. Box 06017 Ft. Myers, FL 33906 ■ {813)936-2397 ' CALL 1-800-237-3063 FREE (Except Florida) CIRCLE 104 ON FREE INFORMATION CARD CHEMICAL SOLUTIONS FREE CHEMTRONICS CATALOG! Comprehensive new source for over 200 products used in electronic man- ufacturing and field service. 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CIE is the largest independent home study school in the world that specializes exclusively in electronics. Meet the Electronics Specialists. When you pick an electronics school, you're getting ready to invest some lime and money. And your whole Future depends on the education you get in return. Thai's why it makes so much sense to go with number one , . . with the specialists . . . with CIE! There's no such thing as bargain education. If you talk with some of our graduates, chances are you'd find a lot of ihem shopped around for their training. Not for the lowest priced but for the best. They pretty much knew what was available when they picked C1E as number one. We don't promise you the moon. We do promise you a proven way to build valuable career skills. The C1E faculty and staff are dedicated to that. When you graduate, your diploma shows employers you know what you're about. Today, it's pretty hard to put a price on that. Because we're specialists we have to stay ahead. At CIE, we've got a position of leadership to maintain. Here are some of the ways we hang onto it . . . Programmed Learning That's exactly what happens with CIE's Auto-Programmed Lessons. Each lesson uses famous "programmed learn- ing" methods to teach you important principles. You explore them, master ihem completely, before you start to apply them. You thoroughly understand each step before you go on to the next. You learn at your own pace. And, beyond theory, some courses come fully equipped with electronics gear (the things you see in technical magazines) to actually let you perform hundreds oT "hands-on" experiments. Experienced specialists work closely with you. Even though you study at home, you are noi alone! Each time you return a completed lesson, you can be sure it will be reviewed, graded, and returned with appropriate instructional help. When you need additional individual help, you get it fast and in writing from the faculty technical specialist best qualified to answer your question in terms you can understand. Pick the pace that's right for you. CIE understands people need to learn at their own pace. There's no pressure to keep up ... no slow learners hold you back. If you're a beginner, you start with the basics. If you already know some electronics, you move ahead to your own level. Enjoy the promptness of CIE's "same day" grading cycle. When we receive your lesson before noon Monday through Saturday, we grade it and mail it back the same day. You find out quickly how well you're doing! Microprocessor Trainer State-of-the-art Laboratory Equipment Some courses feature the CIE Microprocessor Training Laboratory. An integral part of computers, microprocessor technology is used in many phases of business, including ser- vice and manufacturing industries. The MTL gives you the opportunity to program it and interface it with LED displays, memory devices, and switches. You'll gain all the practical experience needed to work with state-of-the-art equipment of today and tomorrow. CEE offers you an Associate Degree. One of the best credentials you can have in electronics — or any other career field — is a college degree. That's why CIE gives you the oppor- tunity to earn an Associate in Applied Science in Electronics Engineering Technology. Any CIE career course can offer you credit toward the degree — more than half of the number needed in some cases. "Cleveland Institute of Electronics is the only accredited institution of higher learning offering an Associate Degree program with tuition based on actual study time used. The faster you com- plete your degree assignments, the less your overall tuition. " steve Simcic Vice-President Academic Affairs Which CIE Training fits you? Beginner? Intermediate? Advanced? CIE home study courses are designed for ambitious people at all entry levels. People who may have: 1. No previous electronics knowledge, but do have an interest in it; 2, Some basic knowledge or experience in electronics; 3. In-depth working experience or prior training in electronics. You can start where you fit and fit where you start, then go on from there to your Diploma, Associate Degree, and career. Today is the day. Send now. Fill in and return the postage-free card attached. If some ambitious person has removed it, cut out and mail the coupon. You'll get a FREE school catalog plus complete information on independent home study. For your convenience, we'll try to have a CIE representative contact you to answer any questions you may have. Mail in the coupon below or, if you prefer, call toil- free 1-800-321-2155 (in Ohio, 1-800-523-9109). I CIE Cleveland Institute of Electronics, Inc. 1776 Ease 17th Street. 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Save $1501 38 CIRCLE 103 ON FREE INFORMATION CARD o. MUM in 1311) YOU KNOW THAT WITH A .STANDARD FM-broadca$l receiver you can only hear part of the signals available on that band? The rest, called SCA {Subsidiary Com- munications Authorization) transmis- sions, are hidden away on subca triers and are intended to be received only by certain segments of the public. SCA originated with the founding of the S8-108-MHz band in the 1940's. It was intended as an income producer to help FM stations financially until the band became economically viable. It has been used for various purposes, such as back- ground music without commercials for restaurants and offices, for medical news, for second-language programming, and for radio reading and news services for the visually handicapped. In this article we are going to explore the world of SCA. We'll discuss, what it is, what makes it possible, and what types of programs and services make use of it. We'll also show you how to build an FM stereo/SCA receiver that will let you tune in to all of the signals on the FM band. But before we get too far along, it would be helpful to have an understanding of FM-radio basics. Let's take care of that step first. FM-radio basics An FM {Frequency Modulation) signal is simply any RF (fladio Frequency) sig- nal whose instantaneous frequency is de- termined by the modulation. The deviation of an FM signal is the compo- nent of change in carrier frequency that is determined by the amplitude (primarily) and frequency of the modulating signal. In the U.S., FM broadcast stations are permitted ± 75-kHz deviation, which is defined as 100% modulation. Both a 20- Hz audio signal and a 15-kHz audio signal can produce 75-kHz deviation because it's the combination of the frequency and the amplitude of the modulating signal (pro- gram audio) that determines the devia- tion. If one volt of fixed-frequency audio produced ± 75-kHz deviation, then one tenth of a volt would produce ±7.5-kHz deviation. Although deviation and modu- lation frequency are independent varia- bles, the ratio of deviation to modulation frequency is called the modulation index, or p, where P = deviation/modulation frequency in a typical FM-broadcast situation, with a I -kHz audio signal at 50% modula- tion (37.5-kHz deviation), p = 37,5 (37.5 kHz/ 1 kHz). It's noisy Because the ear is most sensitive to high-frequency noise, and because the SCA/FM STEREO RECEIVER SCA/FM STEREO RECEIVER • STEREO Z POWEB TUNE FM SCA ON TUNING DOC POWER VOLUME PHONES Tune into the "hidden" signals on your FM dial with this SCA receiver. RUDOLF GRAF and WILLIAM SHEETS FCC wanted FM to have the best possible signal-to-noise ratio, FM broadcasting in- corporates a system of prcemphasis/ deemphasis equalization, whose param- eters are based on the fact that the high- frequency energy of the sounds that are commonly part of programming de- creases at an almost fixed rate per octave above 1000 Hz. (That was before the era of electronic instruments.) That allows the high frequencies to be preemphasized be- fore transmission, and mirror-image deemphasized at the receiver. The end product is a "flat audio response"; however, noise generated anywhere be- tween the preemphasis and the deem- phasis (such as atmospheric noise) is attenuated. Because the equalization re- flects nature's own frequency charac- teristics, it is therefore possible to preemphasize say. a concert orchestra that is reading 100% modulation on a VU WARNING! SCA is not a broadcast service, and SCA transmissions are not intended tor reception by the general public. As a result, SCA transmissions may be governed by Section 605 of the FCC Rules, which forbid unauthorized indi- viduals from receiving such communi- cations and using them for their own or other's profit, or divuiging their con- tents, intent, or meaning to any other unauthorized individual. Many for-profit services make use of SCA, and reception of those in most cases is permitted by paying subscrib- ers, and under certain circumstances, only. Some not-for-profit services do make use of SCA also, however, such as those providing assistance to the blind. It may be possible to receive those without obtaining prior permis- sion or paying a subscription fee, as long as the terms of Section 605 are observed. We advise you to contact the approriate programmers in your area for more information and to ob- tain any necessary authorizations. > o c; w CD 39 meter (which indicates average rather than peak power) without worrying that the preemphasi/.ed highs will cause over- modulation of the transmitter. Electronic instruments and "'signal processors" that came along many years after the founding of the modem FM band were to interfere with the established pre- emphasis/deemphasis concept; however. the equalization is still required to ensure optimum signal-to-noise ratio, lalthough it can be modified to accommodate FM- Dolby transmissions). By the way. if FM preemphasis/deemphasis noi.se reduction sounds similar to Dolby-B tape noise re- duction it's because they are similar in overall concept. Dolby simply "floats'' the high-frequency reference level. Pre-emphasis/de-emphasis of some kind is used in all forms of FM communi- cations, including SCA. That is, the FM si una I has it. and so docs the SCA signal. Because the earliest FM detector was also an AM detector it was sensitive to AM atmospheric noise t static), and so re- ceivers used IF I i miter ampliliers to clip the amplitude level of the IF signal so that most AM variations — including those caused by mullipath reception— we re eliminated before the signal was detected. Even though modern FM detectors barely respond — if at all — to AM signal varia- tions, receivers still use IF limiting to ensure minimum AM noise, and in par- ticular, to eliminate many troublesome effects caused by multipath reception. FM bandwidth The occupied bandwidth of an FM sig- nal, at first glance, appears to be simply the peak-to-peak deviation. However, that is not always true. A 75-kHz deviation FM broadcast signal, for instance, re- quires somewhat more bandwidth than simply the peak-to-peak deviation. Ob- viously, it is important to know the re- quired bandwidth for various reasons, among them channel spacing, necessary receiver bandwidth, and signal-to-noise ratio considerations. For signals with a very high modulation index, the necessary bandwidth is very close to the peak-lo-peak deviation. As an example, that would be true for a I009r- modulated FM signal (75-kHz deviation in commercial broadcasting) with low au- dio-frequency modulation (on the order of 20 Hz, for example). However, the situa- tion changes for signals with a low modu- lation index. At a modulation index of 10 the bandwidth required would be about 2.b' times the peak-to-peak deviation (75 kHz), or 210 kHz, At a modulation index of 5 (as would result from a 75-kHz signal with 15-kHz audio modulation) about 3.3 times the peak-to-peak deviation, or 247 kHz. would be required. That increased bandwidth is due to the sidebands generated in FM. The side- bands, as in the AM case, arc separated by the modulation frequency from the car- rier. However, depending on the modula- tion index, the sidebands vary in amplitude. They appear, reach a max- imum, then, at higher modulation in- dices, some sidebands disappear. In fact. the carrier disappears at a modulation in- dex of 2.4. That means, if we apply a tone of about 31 kHz to an FM transmitter and adjust the level of the tone to produce a deviation of 75 kHz, the carrier will actu- ally null out. Of course, the FM signal has not disappeared — all of its energy is now contained in sidebands spaced 31 kHz from the carrier — at ± 31 kHz, ± 62 kHz. ±93 kHz. etc. While the mathematics required to de- scribe sideband amplitude and hence re- quired bandwidth arc very complex . a rule of thumb that works out relatively well in practice for low distortion is that the re- quired receiver bandwidth is approx- imately twice the deviation plus the highest modulating frequency. That fig- ures out to about 240 kHz for an FM- stereo/SCA receiver. Note that FCC chan- nel band widths are 150 kHz, with 50 kHz guardbands between assigned channels. As another example, commercial 2- way FM radio used for police, fire, taxi- cab, etc. as well as 2 meter FM radio use ±5-kHz deviation with audio restricted to 3 kHz (3000 Hz). Receivers for those ser- vices use 13-kHz bandwidth IF filters. That, of course, is twice the deviation plus the highest modulation frequency. The FM signal The various components of a stereo FM broadcast signal are as follows: • Audio baseband (0-15 kHz). That is a monophonic signal comprised of the sum of the left and the right (L+R) audio channels; it is the program audio received by a a monophonic FM radio. • Stereo baseband (19 kHz and 23-53 kHz). That consists of the pilot carrier at 19 kHz. and a DSB (Double Sidcfland) suppressed carrier AM signal centered at 38 kHz. The 38-kHz carrier is sup- pressed, and the low-level pilot carrier at 19 kHz is used by the receiver to regene- rate the 38 kHz suppressed carrier. In that way the 38 kHz DSB signal is recovered and detected. That signal is comprised of the difference between the left and right y z O EC (— O □ < tr POIfNTIOMHER ■*■ HIGH PASS FILTER SCA DETECTOR MPX DECODER -r^T FIG. 1— OUR SCA RECEIVER is shown here in block diagram form. 40 PARTS LIST Resistors Vt watt, 10% unless otherwise noted R1, R3. R7, R8, R10, R46, R6Q— 100.000 ohms R2— 47,000 ohms R4, R25, R28. R68, R7Q— 100 ohms R5, R31, R32, R35— 470 Ohms R6. R21, R39— 150 ohms R9.R1 1—220 ohms R12, R14, R18— 2200 ohms R 13— 3500 ohms R15, R30. R56, R57, R62. R66, R76— 1000 ohms R16, R23. R27, R36-R38. R40, R43, R45. R49. R54, R58, R59, R61 — 10,000 Ohms R17— 1 megohm R19, R67, R69— 10 ohms R20, R24, R29. R33— 330 Ohms R22, R26— 33,000 Ohms R34, R42. R44— 22,000 ohms R41, R47, R51-R53. R64, R65— 4700 ohms R48, R50— 18,000 ohms R55, R63— 15,000 ohms R71-R75-1 0.000 ohms, potentiometer Capacitors C1. C7, C17— 2-18 pF trimmer C2, C5. C6. C8, C9, Gil, C13-C15, C18, C20-C26. C28, C30-C34— 0.01 jiF, ceramic disc C3. C4, C56 — 470 pF, ceramic disc C10, C16, C37—1O0 pF, silver mica C12, C29, C35, C36, C39, C47, C49, C59, C62— 10 (J.F, 16 volts, electrolytic C19— 8 pF, silver mica C27-not used C38— 3-40 pF, trimmer C40-C43— 220 pF, silver mica C44--0.001 jiF, Mylar C45, C60, C63— 0.1 |j.F T Mylar C46, C51— 0.047 |i.F. Mylar C48, C52— 0.0022 ^F, Mylar C50, C53-— 0,22 (xF, Mylar or tantalum C54— 0.47 (iF, Mylar or tantalum C55, C65 — 470 pF, silver mica C56, C57— 0.022 jxR Mylar C58. C61, C64 — 470 tiF. 16 volts, elec- trolytic Semiconductors IC1— LM3189N FM receiver IF system (National) audio channels (L-R). [n a stereo re- ceiver, the L — R and L + R signals are combined in such a way as to recreate the left and right audio channels. • ARI (Automobile /fadio /reformation) subcarrier(57 kHz). That is a narrow-band channel used for traffic bulletins. Ori- ginated in Europe, that service has been recently implemented here and may be- come popular in the future. It is currently used on a trail basis in some major metro- politan areas. • SCA subcarrier (most often 67 kHz and/or 92 kHz). The SCA subcarrier is used for "hidden" radio programs, back- ground music, and digital data transmis- sion. The signals are FM with ±7.5-kHz deviation maximum. SCA is not a high fidelity service; its audio-response band- 1C2— LM565 phase-locked loop (Nation- al) IC3— LM1310N FM stereo demodulator (National) 1C4, IC5— LM386 audio amplifier (Nation- al) Q1 , Q2^t0673 dual gate MOSFET transistor Q3-Q5— 2N3563 NPN transistor Q6, Q7— 2N3565 NPN transistor DJ. D2, D4— MV2107 varactor diode D3— 1N757 diode D5— 1N4001 diode LED1— jumbo red LED LED2— jumbo green LED Other components Li. L3, L5— see text 12, L4— 1.8 n-H L6, L7— 18 m-H CF1-CF3— 10.7 MHz ceramic filter J1— stereo headphone jack J2-J8 — phono jacks, RCA type S1— SPST toggle switch S2— 3P4T rotary switch Miscellaneous— PC board, No. 20 solid uninsulated wine for winding L1 . L3, and L5 (18 inches total required), wire, sol- der, hardware, knobs, cabinet, etc. The following are available from North Country Radio, P.O. Sox 53, Wykagyl Station, NY 11804: Kit consisting of PC board and all PC-board mounted parts (jacks, switches, 05, LED's, power-supply components, etc. not included), $75.00 plus $2.50 postage and handling; Etched and drilled PC board, $12.50 plus $2.50 postage and handling. NY residents please add appropriate sales tax. PARTS LIST— POWER SUPPLY C67— 2200 m-F, 25 volts, electrolytic C68— 0.01 u.F, ceramic disc C69 — 0.1 u.F, ceramic disc C70 — 470 m-F. 16 volts, electrolytic T1 — 117-voit primary, 16-18 volt 500-mA secondary IC6— LM7812 Ihree-terminai regulator D6-D9— 1N4001 diode width is limited to about 5000 Hz. Our immediate interest, of course, is in the SCA signal. It is normally used as an auxiliary, income- producing service by the operators of an FM broadcast station. However, we do not get something for nothing. Modulating any of an FM chan- nel's sub-carriers reduces the maximum modulation available for the main audio channel. In the case of SCA, modulating one subcarrier of a stereo signal uses up about 10% maximum of the total 75 kHz deviation (100% modulation). In practice, that reduces the main channel's signal strength by about 1 dB. Normally, such a drop in signal level would not be notice- able. However in areas with crowded FM bands, every dB counts in the race for ratings, and revenue. Stations in those locations are likely to think twice about using both available SCA subcarriers. which would cost about 2 dB in signal level, let alone ARI, etc. On the other hand, leasing those subcarriers can be a significant source of income for the li- cense owner, SCA is noisy At best, the SCA of a stereo-FM signal can represent only 10% of the total FM transmission; hence, the received SCA signal is unusually weak, and therefore prone to be noisy. Also, depending on the design of the receiver and the care taken with the SCA signal at the transmitter, the received SCA can suffer from "splatter" or "spillover sputter" from an FM sta- tion's main audio channel. The splatter and sputter is usually 30-40 dB below the SCA audio, but that's a level that can be heard as intermittent "noise." With prop- er filtering in the receiver, however, main- channel interference to the SCA caused by the receiver's circuits — not by the transmitter — can be attenuated low enough so it can't be heard. In fact, the SCA channel — particularly when received on an SCA-dedicated re- ceiver — is good enough so that in addition to background music it has been used for digitized stock-market quotes, digital- data transmission, telemetry, radio pag- ing, and slow-scan color TV. And at pres- ent, out in California (where else?) the SCA is being used to distribute informa- tion and advertising to computer users in the Los Angeles area. Receiving SCA A block diagram of our SCA/FM-ster- eo receiver is shown in Fig. I. The com- plete schematic is shown in Fig. 2. The circuit uses a MOSFET RF amplifier whose input and output (mixer) circuits are tuned by varactor diodes. Those varac- tors can be thought of as voltage-variable tuning capacitors. The DC tuning voltage is variable from about 1.5- to 8- volts DC. The local oscillator operates at the tuned signal frequency plus 10.7 MHz. The os- cillator is also tuned by means of a varac- tor diode. The three varactors are biased by a common DC bias line, so as to simul- taneously tune the RF amp, mixer, and oscillator circuits. The mixer output circuit is tuned to 10.7 MHz and feeds an IP preamplifier that has a gain of about 30 dB. This pre- amplifier uses two transistors and three fixed-tuned ceramic IF filters centered at 10,7 MHz. Since the filters are fixed- tuned, no alignment is necessary. That eliminates the need for complex sweep alignment and allows a novice builder to > automatically get the good IF-bandpass ^ response necessary for SCA/FM-stereo c: reception. -i A National LM3189N FM receiver IF 3j system (an RCA CA3I89E can be sub- 5 41 FIG. 2— THREE OF THE INDUCTORS shown in this schematic diagram must be wound by hand. Even so. they are simple to make; complete details will be given in the next installment of the article. CO O z O rr t- o LU o Q < rr stiluted) iC. ICI. performs limiting and quadrature detection of ihe FM signal, and recovers the original audio baseband. Thai IC offers high gain, good limiting, and low-distortion detection. It also provides an AFC voltage to correct drift in the local oscillator and to aid in tuning a selected station. Due to the very high gain, layout is very critical and we strong- ly recommend using the PC layout that will be presented next lime. Otherwise you may leave yourself open to RF-in- slability problems. The audio output of the LM3I89N is fed to an 2N3565 audio amplifier, which delivers an output level of about 3-volts p- p. That baseband audio is used to feed the phase-loeked-loop SCA detector (an LM565) and the FM -stereo detector (an LM1310NJ. A high pass and twin-T R-C filter de- signed to reject frequencies below 50 kHz passes the SCA carrier to the LM565. The output of the IC is the VCO control volt- age, which follows instantaneous fre- quency variations of the 67- or 92-kHz subcarrier. That output (about 50 to 100 millivolts p-p) is the SCA audio. It is passed through a low-pass de-emphasis R- C network to remove high-frequency noise. An SCA audio amp (a 2N3565) amplifies the signal to about 500-rnV p-p, which is sufficient to fully drive the audio power amplifiers. The LM 13 ION is designed to accept the baseband audio and reproduce the origi- nal L and R audio channels. Baseband audio of about 2-3-volts p-p is fed to the LMI310N and L and R audio signals ap- 42 pear at the outputs. Shunt connected ca- pacitors provide de-emphasis. An LED can be connected to the decoder to indi- cate stereo reception. A 3P4T (three pole. 4 throw) switch selects among FM (stereo in the case of stereo broadcasts), SCA, tune, and auxili- ary positions for input to the dual power amps. In the tune position, FM main channel audio is input to one of the amps while SCA audio is input to the other. That makes tuning in an SCA subcarrier easier; more details will be provided when we talk about using the receiver. In the auxiliary position the unit becomes a power amp and will accept an external input via its link in jacks. The dual power amps are identical and are built around a pair of LM386N's. Power output is 'A watt (500 mW) per channel. That is sufficient to drive a pair of small speakers, but we recommend using stereo headphones for best results. If desired, the LM3S6N amps can be omitted and the outputs fed to the line inputs or tuner inputs of an audio system. About 500 mV into a 10k load is available at the l ink out jacks. More detail Looking at the circuit in more detail. FM signals from the antenna are applied between the tap on LI, which is the anten- na coil, and ground. The antenna coil is tuned by CI and varactor Dl to the signal frequency. The varactor has a variable back bias of 1.5 to 8 volts across it. That will sweep its capacitance from 15 to 30 pF When that capacitance is added to the > Q C CO CO 43 stray capacitance on the board and the input capacitance of Ql . it yields a tuning range of 87—109 MHz; that is mure than sufficient to cover the complete FM broadcast band. Capacitor C2 provides an RF ground and allows DC bias from the tuning-volt- age line to be supplied through Rl.lt also cleans up any noise present on the tuning voltage line. No DC current Hows in Rl. and therefore there is no voltage drop across that component. The tap on LI is placed so that QI sees a high input impedance. Transistor Ql is a 40673 MOSFET device with a noise fig- ure of 4 dB or less ( typically 2-3 dB at FM frequencies): that ensures high' sensitivity and there is no base-emitter junction to cause unwanted rectification of strong sig- nals. Resistor R4 and capacitor C3 provide biasing and RF grounding for Ql"s source terminal. The 02 terminal, is biased at about +4 volts by R2 and R3. and C4 bypasses that terminal to ground. The gain of the stage may be controlled by reducing that bias to — 2 volts (cut-off) for AGC purposes. However. AGC was not necessary in the receiver, and was not used. Tire drain is biased through R6 and L2 to about + 1 1- volts DC. Drain current (which is exactly equal to the source cur- rent) is about six to eight milliamperes. Resistor R5 limits the stage gain to about 6 times. That is the optimum amount of gain to ensure circuit stability: it is quite adequate to override mixer noise, yet not so high as to unnecessarily overload the mixer on strong signals. Fur- ther, it allows about a 3-dB margin for mistracking and errors in alignment of the tuned circuits. Capacitor C6 couples the RF signal to L3. which serves to tune the mixer input. Capacitor C5 is an RF bypass and resistor R6 decouples the RF stage from the + 12- volt line. The mixer-input tuned circuit is tuned by C7 and D2, with stray circuit capaci- tances once again playing a role. Ideally, total capacitance in the circuit is exactly equal to that in the antenna circuit. However, the operating Q is a little higher (about 30). The overall RF" bandwidth is about 2 to 3 MHz. which provides quite adequate image rejection — about -30 dB or better. The mixer is driven by a signal of about 3-4 volts p-p on G2 of Q2. Since the transeonductancc of the 40673 is a func- tion of the G2 voltage with respect to the source, the local oscillator (more on that <fi in a moment) signal in effect modulates y the transconductance of Q2. That results O in the 40673 acting as a inker. Resistor jE RH returns G2 to DC ground. Resjstor R9 Jr] and capacitor C9 provide about a 0.6-volt jjj bias, which places both gates at about O -0.6 volt, with respect to the source ter- g minal. The power gain of the mixer (the rr ratio of the IF signal at 10.7 MFlz to the 16-lBv/50QmA k^Dfi 117 VAC 09_V 141 1N40Q1 1 1 IC6 LM7812 o fai 4- 3> C67 220%F 25V ™ C70 « 471V F 16V -C6B C C69- I FIG. 3— THE CIRCUIT REQUIRES a regulated 12-volt power supply. The one shown here fills the bill nicely. RF input signal) is about 12 to 15 dB, depending on local oscillator drive level. The local oscillator uses a2N3563 tran- sistor. Q3. whose operating point is 4 volts al 1.5 milliamperes. That operating point is established by the network com- prised of RI2. R13, RI4. and R15. Note that the local oscillator is actually a volt- age controlled oscillator set up to be in the common-base mode at RF frequencies. At such frequencies. C!4 grounds the base of Q3 . Inductor L4 is an RF choke that is used to teed DC voltage to the collector of Q3. Capacitor CIS couples the tank circuit made up of L5, C17, and D4 to (he collec- tor of Q3. That tank circuit is used to determine the oscillator frequency, which should be 10.7 MHz above or below the signal frequency. In this receiver, the local oscillator operates 10.7 MHz above the incoming signal. Therefore, it must tune from about 98 to 120 MHz. "The spacing should be 10.7 MHz over the entire tuning range of 87-109 MHz, Resistors R16 and RI7 are used to couple the AFC correction voltage to the tuning line, eliminating the need for a separate AFC tuning diode. The value of R16 can be anything from IK to 100K, depending on how much AFC is desired. We used a 10K unit. As previously mentioned, L5 and CI9 match the mixer to ceramic filter FLI. Those components also help prevent un- wanted VHF components from leaking into the IF stages, which could cause spu- rious responses. A ceramic filter is a piezoelectric device that is the equivalent of an IF transformer. It acts as a double- tuned transformer with a 1-dB bandwidth of 250 kHz, centered at 10.7 MHz. The device's insertion loss is about 6 dB. and its termination impedance is specified as 330 ohms. The first IF amplifier is built around Q4. That transistor is biased by R22, R23. and R25 to about 2 milliamperes when the collector voltage is 4. Ceramic filter FL2 couples Q4 loQ5, which is biased identi- cally to Q4. using R26. R27, and R28. Capacitors C21 and C22 bypass the emit- ters of Q4 and Q/5 respectively. The IF stages are decoupled from the power-sup- ply line by R32. R3I. C24, and C23, Resistor R30 is used to determine the op- erating points of Q4 andQ5. It results in a + 4.5-volt supply to those stages, form- ing a voltage divider with R31 and R32. The IF signal is coupled to the I i miter/ detector stage ( IC1 and peripheral compo- nents) by FL3. The three ceramic filters shape the IF bandpass of the receiver. They are fixed tuned and no alignment is required. The gai n of Q4 and Q5 is about 26 to 30 dB. That gives a total gain so far. from the antenna, of about 55 to 60 dB, ensuring that the front -end noise will cause limiting in 1CI. The maximum output of Q5 is about 0.25 volt, which is the saturation point, no matter how strong a signal is received: ICI can easily handle that with- out distortion. No AGC was found neces- sary in this receiver. Most the functions of an FM IF system are provided by ICI . That device includes a three-stage limiter, signal-level detec- tors, a quadrature detector, and an audio amplifier with optional muting circuit (squelch). It has its own internal reg- ulators for DC voltages, and can drive an external tuning meter. While we specified using a National LM3819N, an RCA CA3189E is pin-for-pin compatible with that device and can be used in its place. Use whichever IC is easiest for you to find. Input signal from FL3 is applied to pin I of IC I . R33 is a bias resistor and also terminates FLI. Capacitors C25 and C26 are RF bypass capacitors. The 12-volt sup- ply line is connected to pin II of ICI by R19, C31. R39. and C32: those compo- nents provide RF decoupling as well. While they are not used in the receiver, the IC's squelch (mute) circuits must be ter- minated; R34. C28. C29. R35. and R36 serve that function. An optional tuning meter can be in- stalled in the receiver. We chose not to do so, but if you do, install it at the junction of C30 and R37 as indicated in Fig. 1. Otherwise, the junction makes a good test point for aligning of the front -end's tuned circuits. continued on page 81 44 o MWq} ROSS ORTMAN Versatile Digital Timer You don't need a fancy microprocessor-based timer to turn a device off and on several times a day. This easy-to-build and inexpensive timer will do it with no hassle! 1IM1RS CONTROL EVERYTHING FROM SB- curity systems to computer systems to cof- fee makers — the list goes on and on. Timers vary in sophistication from simple mechanical devices to microprocessor- based controllers. But there is a middle ground. A low- cost module allows you to build a high-performance unit that oper- ates like a VCR timer, is inexpensive, and is very easy to build. The timer allows three on/off set points per day, and it can control any device that draws as much as 6 amps of current. If the timer's output ca- pacity is insufficient, you can easily add an output switching device with greater capacity. The timer can be built for about $60 using all new parts. How it works The timer's schematic is shown in Fig. 1 . The heart of the timer is the PCIM 2303 LCD timer/clock module, made by PCI (Printed Circuits International, 1145 Sonora Court, Sunnyvale, CA 94086). The 2303 module contains the timer IC, clock crystal, an LCD display, and all support components. It requires only 1.5 volts and draws a maximum of 10 pA. Tli at low power requirement allows the module to be powered by a single A A battery, which makes it great for use in portable equipment. The module has a single output that is high during the on period and low during the off period. Because the output is powered by the module, it cannot deliver any appreciable current. Therefore the control voltage is fed to a transistor switch composed of Ql, Q2, R3, and R4. The switch circuit in turn controls IC1, an MOC3010 optocoupler, which isolates the power-control section from the rest of the circuit. The power-control section is composed of Triac TR1 , current-limiting resistor R5, and an MOV (Metal Oxide Varistor). The latter protects the triac and the op- tocoupler from power-line spikes and transients caused by highly inductive loads. The power supply is composed of Tl , Dl, and Ci; it provides nine- volts DC that powers the switch circuitry. It can also be used to trickle-charge a Ni-Cd battery. Although a regular lead-acid or alkaline battery will last for quite sometime, a 1.5- volt rechargeable battery will give best results. The 1-mA trickle charge supplied by optional components D2 and Rl should increase battery life indefinitely. If those components are not installed, never apply power to the unit without a battery in place, or damage to the PCIM 2303 module may result. The specified Triac is rated at 6 amps. If that is inadequate for your application, a larger one can be used. Regardless of which Triac is used, it will generate heat, so provide an adequate heatsink and ade- quate ventilation to avoid overheating. Fuse Fl protects not only the transformer and circuitry, but also the Triac. If a de- vice tries to draw more current than the Triac can handle, the fuse will blow, thus saving the Triac from damage. If you use a Triac with a larger current rating, be sure to install a fuse of the proper size. Other types of power-control circuits are possible; several examples are shown in Fig. 2. An SCR-based circuit is shown in Fig, 2-a, and a relay-based circuit in Fig. 2-b. If you use a different circuit, be sure to isolate the timer module from the voltage being switched. And whether you use a relay, a Triac, an SCR, or some other device, be sure it can handle the max- imum current the device you want to con- trol will draw. Construction The timer circuit is simple enough to be wired using point-to-point techniques; but for a cleaner layout, PC boards can be used. You can purchase pre-etched and drilled boards from the source mentioned in the Parts List; alternatively, foil patterns for etching your own board are shown in PC Service. As shown in Fig. 3, the dis- play board contains the timer module and S1-S4. The main board, shown in Fig. 4, contains the power supply, the battery, the switching circuit and the output circuit. If you use a different output-switching cir- cuit you can alter the design of that board to fit your application. > c o c 45 FIG. 1— SCHEMATIC DIAGRAM OF THE TIMER. The PCIM 2303 timer module contains all timing circuits and an LCD display. to O o £ o Lil _J HI O □ < DC FIG. 2— AN SCR (a) OR RELAY OUTPUT (6) driv- er can be substituted for the triac output circuit in Fig. 1. Stuff the boards in the usual manner, starting with the low-profile components, and working up to the larger ones. The timer module contains CMOS circuitry, so handle it with care. Be sure to observe the polarities of capacitor CI and the sem- iconductors. Install the transformer last, making sure that it is installed correctly. An excellent case for the timer is men- tioned in the Parts List. If you use the specified case, note the limited clearance between the bottom of the PC board and the case. Be sure to insert a piece of fish- paper (or some other insulator), between the board and the bottom of the case to avoid shorts — and possible shocks. Note, in Fig. 4 and Fig. 5, the small strip of PC board material glued to the top of the main board behind the display board. That strip reduces stress on the module and prevents the display board from bending when the pushbuttons are pressed. The remainder of construction is straightfoward. In our prototype the mod- <S4 PSET S3 HRS OHRS TO FIG. 4 GIID- — L_S2 -O OMIN T si -O nMAM MODULE OUTPUT L TIMER/ CLOCK MODULE FIG. 3— THE TIMING MODULE and four switch- es mount on the display board, which connects to the main board via three wires. ule (and the attached PC board with switches) is glued from behind to an opening in the front panel . Testing After mounting all components, in- spect your work carefully for open solder joints, solder bridges, etc. Correct any mistakes. Then insert a battery into the holder, being sure to observe polarity. Now press the set and man buttons simultaneously to reset the module. If the module doesn't display anything, re-check your wiring. After you get the module to reset, plug the line cord into an AC oudet, and plug a table lamp (or other electrical device) into SOI and press the man button. The light should turn on. If it doesn't, check the module's output pin. It should have about 1 . 1 volts on it. If it does, make sure that Ql and Q2 are turning on and enabling the LED inlCl. If the LED is turning on, you should measure about 1.4 volts across it. If the LED does turn on, the problem lies with the AC portion of the circuit. Be very careful when troubleshooting the AC section, because it has 117-volts AC across it. Check for wiring errors; other- wise, the triac may be bad. After you get the circuit working, as- semble the case. The timer is now ready to go to work for you in whatever application you see fit. Operation Programming the timer is very similar to programming a VCR timer. At initial power-up, the device must be reset. That's 46 13/32 +^ +- 9/32 SEE TEXT -+V »GND I R3 I I R1 MODLILC OUTPUT TO "F1G3 111 ^a< *f ' R , 4 O02 I — R2- ricii R5 SOI + FIG. 4 — STUFF THE MAIN BOARD as shown here. Three wires connect to corresponding points on the display hoard, as shown in Fig. 3. current time, which is indicated by a flashing colon. The programmed timer will now turn the device you connected on and off at the preset times. The man button allows you to override the present state of the timer manually. If the output is off when the man button is pressed, the output will tum on. Con- versely, if the output is on, pressing the man button will turn the output off. After pressing the man button, the state of the output remains constant until the man button is pressed again, or until a preset time forces the output of the timer into a different state. The man button controls another im- portant function. It can be used to override the pre- set times. For example, to over- ride the first on time, advance the set mode until the first on time is reached and press the man button. An A' will appear in the display; it indicates thai the first on time has been overridden. The timer will then ignore the locked-out set point until it is "unlocked" by repeating the lock-out sequence. Applications The timer is versatile, so its applica- tions are virtually limitless. As a stereo limer, the unit outperforms most commer- cially available systems. The timer could be programmed to turn your stereo on in the morning, turn it off just after you leave for work or school, tum it on just as you are getting home, and turn it off after you have gone to bed. The unit could also be used to control house lighting for convenience or se- curity. When used as a security device, a oispij* ai sura STOP FIG. 5— THE COMPLETE TIMER CIRCUIT ap- pears as shown here. Trim the PC board so that it fits into the case properly, and Insert a sheet of Insulating paper between the board and the bot- tom of the case. accomplished by pressing the stir and man buttons simultaneously. Then the correct time must be entered, Press set once to enter the set mode; a flashing T will be displayed. Now set hours and min- utes by pressing the hrs and min buttons as appropriate. The displayed hours (or minutes) will advance once for each press of the button; if you keep the button pressed, the display will advance continu- ously at a rate of about two digits per second. By pressing the set button again, the first on time can be set in the same way that time is set. Then press the slt button again to set the first off time. By con- tinuing to press the set button, the second and third on and off times can be pro- grammed into the uoJt, After the third off time is set, pressing the set button once more returns the unit to displaying the ! PARTS LIST All resistors are Vi-watt, 5% unless oth- erwise noted. H1— 4700 ohms R2— 470 ohms R3— 47,000 ohms R4 — 100.000 ohms R5— 180 ohms Capacitors Ct— 220 nR 16 volts, electrolytic Semiconductors IC1— MOC3010 Optocoupler (Radio Shack 276-134 or equivalent) D1. D2— 1N4001 rectifier diode Q1— 2N3904 NPN Transistor Q2— 2N3906 PNP Transistor TR1— 6-amp 400-voit Triac (Radio Shack 276-1000 or equivalent) Other components B1 — 1.5 volts, rechargeable A A batlery F1— 6-amp, 250-volt fuse MOV1— 117-volt metal oxide varistor (Ra- dio Shack 276-568 or equivalent) S1-S4 — SPST, momentary, normally open SOI— chassis-mount AC receptacle T1— 6.3-volt 300mA transformer (Radio- Shack 273-1384, or equivalent) Miscellaneous: PCIM 2303 timer/clock module, chassis-mount fuse holder, bat- tery holder, line cord, case (Radio Shack 270-286). Note: the following are available from Dakota Digital, R. R. 1, Box 83, Can- istota, SD 57012: display PC board, S3. 50; main PC Board, 59,95; PCIM-2303 module, $23.95; module and four pushbutton switches. S26.50. All orders add $1.50 for shipping and handling. South Dakota residents add appropriate sales tax house can be made to look "lived in" by turning the lights on in the morning for a preset time and turning them on and off several times during the evening. If sever- al timers were used to control different lights throughout a house, the effect would be even greater. Other items can be controlled. For ex- ample, you could turn your coffee pot on in the morning 10 minutes before you get up. Then you could always have your morning coffee first thing. You could also control your heating system with the timer, heating your house only while you're home and awake, and turning it off during the day while you're gone and at night while you're asleep. The money saved doing that will add up quickly. During the winter, in cold climates, the timer could be used to turn your car's engine-block heater on in time to warm the block up enough for safe usage. Of course, the PCIM 2303 can be used in many other applications. It's a versatile device and it can be used in countless > applications. Whether you' re replacing an § existing timer or designing a timer system g for a custom application, the PCIM 2303 clockytimer module is the ideal starting point for many designs. R-E to CO 47 ~l ^mtfmsxg&z HIGH DEFINITION TV The most important change in TV technology since it was invented is just over the horizon. g o DC H O o Q < CL CREATED IJY NEON LAMPS AND VIEWED through a spinning spiral of holes in a Nipkow disc, the very first TV images were so crude that they barely allowed the viewer to distinguish light from shadow. Today we are much more fortunate — on- screen resolution of several hundred lines, both horizontally and vertically, permits us to read street signs, subtitles, and movie credits on color CRT's or LCD's. Even so, we're always aware that we're looking at a television picture, that is, a picture displayed on a screen. And when we can not discern the finer details in an image, no matter how hard we strain, the shortcomings of the current system be- comes evident. That is true whether the system in question is the NTSC system used in this country, or the slightly higher- resolution PAL and SECAM systems that have been adopted by most of the rest of the world. But help is on the way. Dramatic im- provements are on the horizon in the form JOSEF BERNARD of tfigh-Definition TV (HDTV) systems that will add realism and detail to the images we view for entertainment and in- formation. HDTV technology exists today; it is used, for example, in Hollywood for spe- cial-effects work in TV. By as early as 1990, Japanese broadcaster NHK plans to have an HDTV system in place and opera- tional. And work here, in Europe, and elsewhere is progressing so fast that sys- tems may be in place worldwide shortly thereafter. In this article we'll examine the Japanese HDTV system and others, see how they evolved, and learn about what obstacles remain before they can become adopted for widespread use. HDTV criteria One of the goals of HDTV is to create a sense of realism for the viewer that's at least as good as that provided by motion- picture film. How 1 ? Tests have shown that, to overcome the " picture- in-a-box" effect of TV viewing, the image must subtend a viewing angle of at least 30°. To obtain such an angle, one could simply sit closer to the screen. However, at a distance of less than 7 times the image height, scan lines become noticeable and give the im- age a grainy appearance. Figure I compares the geometries provided by viewing both conventional TV and HDTV screens from the distance at which scan lines arc rendered invisible. In a conventional system, the viewing an- gle is only about 10°. but an HDTV sys- tem provides the desired 30° viewing angle. As shown in the figure, if the number of scan lines is increased to 1000 or more, the minimum viewing distance is reduced to about 3 times the image height. At that distance a 30° viewing angle can be achieved. Further, due to the limited reso- lution of the human eye, the lines will blend together and give the impression of a smooth image. 48 FIG. 1— THE GEOMETRY OF TV VIEWING. With an HDTV image, a viewer can sit closer to the screen to attain a greater viewing angle, thereby improving the sense of realism. Because the signal has approximately twice as many scan lines as a conventional system, those lines are not visible at distances as close as three times the image height. Another factor adding to the impres- sion of realism offered by HDTV is a change in aspect ratio, the ratio of an image's width to its height. Conventional TV has a 4:3 aspect ratio, which means thiil the picture is four units wide and three units high. That aspect ratio was adopted originally lo conform to what was used at the time for motion-picture photography. These days, most films are shot using the Panavision process, which uses a f .85: 1 (5.55:3) aspect ratio. It is expected that HDTV will use an aspect ratio between the two, with 1. 77: 1 (16:9) being endorsed by many. See Fig. 2. The NHK system As we mentioned earlier, the HDTV system closest to being a practical reality is the one proposed by Japan's NHK. That system uses a signal with 1125 scan lines and a 2:1 interlaced scan rate of 60 fields (30 frames) per second. NHKs HDTV system has already been demonstrated both in Japan and in the U.S. One problem with all HDTV systems is thai they potentially require enormous amounts of bandwidth. For instance, in ihe system proposed by NHK, a high- definition TV picture contains about live times more luminance (brightness) infor- mation that does a conventional one, thus requiring a bandwidth at least five times greater than that specified for the NTSC system used by U.S. broadcasters today. That translates to a bandwidth require- ment of 30 MHz, compared to the 6 MHz NTSC standard. To squeeze all of the information re- quired for a HDTV picture into a more manageable bandwidth, NHK developed a system called MUSE (Mt/ltiple Sub- Nyquist Sampling Encoding). MUSE converts a wideband analog studio signal to digital form, compressing it to slightly more than 8 MHz for transmission. At the receiver, the signal is re-expanded to its original form for display. The MUSE specifications call for: • Processing of luminance and chromi- nance information by TCI (Time Com- pressed /ntegration). • Time-compressed line -sequential pro- cessing of chrominance information gen- erating R - Y (red minus luminance) and B — Y (blue minus luminance) color-dif- ference signals. • Time compression of the chrominance signal by a factor of four. • Bandwidth reduction of the TCI signal through subsampling. • A PCM digital audio signal to be multi- plexed with the video signal. MUSE is known its a "motion-com- pensated subsampling" system. The terms subsampling and sub-Nyquist refer to the fact that when the video information is processed, fewer samples are extracted from it than would be the case if it were to be processed using conventional meth- ods, where sampling occurs at twice the highest frequency (i. e., the Nyquist fre- quency) involved; the lower sampling rate is the reason why that method is called sub-Nyquist. The principal trick used by the MUSE system is that it sub-samples the video signal over a four-field sequence prior to transmission: the sampling pattern used is shown in Fig. 3. That technique allows for the 4:1 reduction in required bandwidth. Reconstruction of the MUSE signal re- quires an HDTV receiver equipped with a memory capable of storing the four fields. For still (non-moving) parts of an image, the picture can be reconstructed using samples from all four fields since there will be no movement from field to field. But where there is movement, attempt- FIG. 2— ASPECT RATIOS. Here, the aspect ratios of conventional-TV, HDTV, and Panavi- sion motion -picture viewing screens are com- pared. -o 4 I » 1 6 - -a- iiit ■ lit j — o i t i ?-^ i i 1 i I i ! * ' 6 1 i i rj— i- SUBSAMPLING POINTS: O 1st FIELD □ 2nd FIELD I 3rd FIELD 4th FIELD FIG. 3— THE SAMPLING PATTERN used by NHKs MUSE system. Picture information Is transmitted over four fields rather than the two of conventional TV. > C D C CO CD CO -J 49 w o o Q < cr_ ing reconstruction using two or more Melds will yield a picture with unaccepta- ble blurring. That's because the picture content will be changing from lield to Held, Therefore, only the information from one field can be used to form the image and a 1:4 loss of resolution occurs. However, a MUSE receiver also incor- porates a motion detector. That stage en- ables the receiver to integrate the stationary and moving pans of a scene into a single image. (That's where the "motion-compensated" part of the MUSE system comes in.) The result is that stationary parts have maximum reso- lution while moving parts appear slightly blurred. Such blurring is not considered serious, however, since our perception of sharpness is not reduced by blur in a mov- ing image. We simply accept it as an at- tribute of the motion. A special case in the MUSE system occurs when the camera is panned or tilted, causing the entire image to change. When the encoding circuitry detects that type of picture content, a vector represent- ing the motion of a scene is calculated and the information is sent during the vertical- blanking interval. At the receiver, the in- formation is applied to the held memo- ries, causing the position of the sampled picture elements to be shifted as appropri- ate to the motion. The bottom line is that the moving pictures are processed as if they were stationary ones, with conspic- uous blur in uniformly moving regions of the image held to a minimum, subject to the accuracy of the motion vectors. Note however that non- uniform moving regions will unavoidably suffer a loss of resolu- tion. In most instances, however, such loss will be acceptable as a consequence of motion. Other systems Although NHK's MUSE system is the one closest to implementation, work on HDTV is also continuing in Europe and the U.S. In this section we will look at some of the more promising systems. Most of these systems are based on the following standard: 1125 lines. 60 frames per second. 2:1 interlace, 16:9 aspect ratio. The number of lines was chosen as a compromise between the PAL/SECAM and the NTSC camps. It is more than 1000 lines, but not exactly equal to twice either 625 or 525 lines. Also, although 50 frames per second is used in Europe and elsewhere, the NTSC standard of 60 frames per second was accepted because it substantially reduces flicker and allows a higher sampling rate. Interlaced scan- ning, as opposed to a progressive scan- ning scheme, is used because of the reduced bandwidth it requires. Note that those specifications have not been formally accepted as a worldwide standard, however It was hoped that a standard would be adopted at the Interna- tional Radio Consultative Committee's 1986 Plenary Assembly. Instead, a deci- sion was postponed until 1990, at the ear- liest. That postponement has added some confusion to the HDTV world, so there is no guarantee as to what shape, if any, a worldwide specification will take. It is expected, however, that the 1125/60/2:1 standard will become a de-facto standard in most 60-Hz HDTV studios. Several of the systems are of the MAC (Multiplexed Analog Components) type. In a MAC signal, the luminance, color difference, and multiple digital sound sig- nals are compressed in time and multi- plexed onto the same signal. In particular. most European HDTV systems are based on some type of MAC system. For instance. Philips, the Dutch elec- tronics giant, has proposed a European HDTV system called HD-MAC. The sys- tem is based on the 625-line. 50-Hz PAL standard. The input signal is 1250 lines, 50 Hz, with 2:1 interlace. Vertical filtering is used to make a wide-bandwidth 625/50/2:1 signal for transmission. The bandwidth is reduced by transmitting only alternating horizontal samples: four fields are required to receive a complete HD-MAC picture. That, once again of course, means that the receiver must have a frame memory to display the 1250/50/2:1 picture. Other MAC systems are similar, except for the numbers involved. For instance, B-MAC is a MAC system that's compati- ble with the 1 1 25/60/2: 1 proposed world- wide standard. And things have not been quiet in this country, either. Bell Laboratories has pro- posed a two-channel transmission system in which one channel contains an NTSC signal that is derived from an HDTV sig- nal of 1050 lines. The second channel contains the high-frequency luminance and color-difference information. Ac- cording to Bell Labs, a normal NTSC receiver would receive the NTSC channel with only a slight degradation of picture quality. An HDTV receiver would receive both channels and combine them using a frame store. The result is then scan-con- verted to reproduce the original 1050- line picture. CBS has proposed another two-channel system. One channel would contain a MAC-like time-multiplexed component signal in a 525-line/60-Hz format. The second channel would contain another time-multiplexed component signal. When the two signals are combined, an HDTV image results. The system does not require a receiver with frame store and would use Direct-Broadcast Satellite (DBS) delivery. William Glenn of the New York. In- stitute of Technology has proposed a sys- tem that makes use of the properties of human vision to reduce the bandwidth of a transmitted HDTV signal. In his pro- posal, an "improved" NTSC signal is transmitted over a standard NTSC chan- nel. (Those improvements could entail pre-combing to eliminate interference be- tween the luminance and color informa- tion, use of progressive rather than interleaved scan. etc. Some improve- ments may require modified NTSC re- ceiving equipment.) That signal, which already will offer somewhat better resolu- tion than standard NTSC, is accompanied by a 3-MHz wide auxiliary signal that contains high-frequency, low tempore I - rate information, as well as information NTSC PIXEL NTSC PIXEL \ EVEN FIELD f SCAN LINE \ ODD FIELD f SCAN LINE NTSC PIXEL A E C A E C A E C B F D B F D B F D V A E C A E ~^ C A E C II 1/1300 PICTUF V ■ M000 PICTL1R EWiDl EHEIG H -IT SAMP A=6n' B = l6n C = (6n X .ETRA » FIELC + 1)'" f i 21'" NSMISSI0N. D = lELD E = t TELD F = ( 6n t- 31'" FIELD So + 41* FIELD in + 5I» FIELD FIG. 4— IN THE DEL RAY HDTV SYSTEM, each NTSC pixel Is broken up into six samples for transmis- sion. Picture information is relayed in a sequence of six fields. 50 required to produce a wide aspect- ratio picture. The two signals would be com- bined in a frame store to produce an HDTV image. The Del Ray Group of Marina Del Ray, CA, has proposed a system that uses a single NTSC channel to transmit a 525/60/2:1 HDTV signal. They propose a system in which a single NTSC lumi- nance sample (pixel) is broken up into 6 samples. One sample is transmitted each field until after 6 fields the complete NTSC pixel is sent. The sampling pattern is shown in Fig. 4. At the receiver, a frame store is used to recreate the complete pic- ture. According to the Del Ray Group, such a signal could be displayed on a non- HDTV NTSC receiver with little degrada- tion when compared with a normal NTSC signal. A wider aspect ratio is achieved in this system by reducing the number of active video lines transmitted by 69. The Del Ray Group contends that due to overscan losses in a typical receiver, the removed lines would not be missed. Further, those 69 lines could then be used to transmit digital sound. Distribution After an HDTV specification has been established and agreed upon, the problem remains of how to distribute material pro- duced in that medium to the public wait- ing for it. So specifications, distribution, and compatibility are HDTV's toughest remaining problems. Let's look at the dis- tribution problem in more detail first; later on we'll delve deeper into compatibility. As with today's video programming, there are two alternatives: broadcast and pre-recorded material. In the realm of broadcasting, one possibility is, of course, DBS. Satellites could provide a distribution route completely independent of those used for conventional broadcast- ing, and the compatibility issue could, in a sense, be skirted. It has been suggested that the most economical and practical system for distributing HDTV is by DBS in the 22- and 40-GHz bands. (For more on HDTV and DBS, see Satellite TV elsewhere in this issue, as well as in the July issue of Radio- Electronics.) Until recently, most observers had ruled out terrestrial broadcasting as a pos- sible distribution medium. However in a test conducted this past January in the Washington, DC area by the NAB (Na- tional Association of Broadcasters) and the MST (Association of Maximum Ser- vice Telecasters), two adjacent UHF channel slots were used to transmit a MUSE HDTV signal. At the same time, a 13-GHz terres trial- microwave relay signal was used as a backup, and to demonstrate the feasibility of using that band in areas where sufficient UHF spectrum was un- available. On the UHF band the broadcast was made using vestigial sideband AM; FIG. 5— AN HDTV videotape recorder from Sony was used this past spring to present one de- signer's spring line in New York. on 13 GHz, FM was used. In general, the results were satisfactory, although some problems were encountered with the PCM digital audio, which was designed for sat- ellite rather than terrestrial distribution, when the signal was attenuated. That problem will have to be solved to make terrestrial distribution of a MUSE signal practical. The other way in which HDTV pro- gramming could be provided is in pre- recorded form — on videotape and vid- eodiscs. While the wide band widths of HDTV are beyond the capabilities of con- ventional broadcast and consumer equip- ment, Sony and other manufacturers have developed systems capable of storing HDTV images. See Fig. 5. Compatibility High-definition television is certainly practical. Indeed, it already exists. The problem that concerns many, though, is how to get program material produced in that medium to the greatest number of viewers. In the past, virtually all improvements in broadcasting in the U.S. have been achieved within the framework of the sys- tem established in the 1940's by the NTSC; other TV systems have also main- tained compatibility with existing equip- ment as they were improved. Although newer receiving equipment has been re- quired to take full advantage of improve- ments such as color and stereophonic broadcasts, program material incorporat- ing those improvements has generally been able to be received and enjoyed using equipment already in use. The ideal, of course, is to develop a system in which a current receiver could accept an HDTV transmission and display it in HDTV form. In all likelihood, that is an unattainable dream. More likely would be a system in which an NTSC receiver would be able to receive an HDTV signal and display it with the same or slightly worse quality as it displays an NTSC sig- nal. Another possibility would be a sys- tem in which an NTSC receiver could be modified, perhaps through an outboard adapter, to receive HDTV signals. Of course, the cost of such a modification must he relativelylow to be practical. If it is too high, most consumers would opt to forgo modification and simply replace their equipment when they decide to up- grade. A final possibility would be that an NTSC receiver simply could not be used to receive and display HDTV signals in any form. In other words, it would be a completely incompatible system. Of course, compatibility is a desirable goal, but you can not overlook the cost at which it is achieved. At this point in HDTV research, it appears that the higher the compatibility with existing systems, the poorer the high-definition perfor- mance. Images will be strikingly better than those provided by a non-HDTV sys- tem, but they will not provide maximum possible performance. On the other hand . the highest perfor- mance HDTV system will likely be achieved only if the compatibility prob- lem is completely ignored. In that event, a separate programming distribution sys- tem likely will develop that will supply programming to viewers that possess the appropriate equipment. Ignoring compatibility altogether is not without precedent. When FM radio broadcasting was introduced, that mode was incompatible with the existing AM system. That, however, did not stop peo- ple from investing in what then was ex- pensive equipment to take full advantage of the benefits (superior audio quality) offered by that medium. The newer FM system coexisted with the older AM one. and prospered. Today, it is commonplace to find AM and FM tuners in the same piece of equipment — - even small portable receivers. And even now the same program material is some- times broadcast by a station in both AM and FM, so that those with FM equipment can enjoy the all the benefits of the new technology, and those who are still AM- bound will not be left out. Similarly, television broadcasters could provide high-quality HDTV program- ming by satellite or some other means to those equipped to receive it, while per- forming scan- and media-conversion at their own facilities and simultaneously sending NTSC- formal signals containing the same material on their conventional VHF and UHF frequencies for viewers with existing NTSC (or PAL or SECAM) receivers. Whatever final form politics, policies, and technology dictate for HDTV, it ap- pears that there's no holding that tech- nology back. In just a few short years, Japanese viewers will be enjoying its ben- efits; it's very likely that shortly thereafter we'll be getting the "big picture" in this country, too! R-E > c Q C to -i 51 mm. LVI.N INK) l"Hh liAKI.Y Yl-.AKS OJ" SOUl> statc equipment design, the FCC's exam- ination lor a 1st Class General Radio- telephone License which is almost universally known as a "First-Phone." covered most of what there was to know about the electronics of communications. Except for radar, which was an endorse- ment on the license obtained through a separate examination, the knowledge needed to gel a First-Phone was so broad and so thorough that the license was often a prerequisite for general technical em- ployment, even though the license was intended only for technicians whose job involved transmitter adjustments. The reason why employers placed so much faith in the First-Phone was because it certified a minimum level of knowledge and skill. Even if the job open was repair- ing home stereo receivers, an employer could be reasonably certain that someone with a First- Phone had an acceptable un- derstanding of both electronics and elec- tric fundamentals. But suddenly, almost overnight, the general radiotelephone license lost both its value and its need. First, as with all other things, electronics technology be- came so complex and sophisticated that no one could be expected to be expert, or even merely competent, in more than one or two specialized areas of interest. Be- cause the radio broadcasting services no longer represented a major area of elec- tronics, having a license that certified competence with transmitters and anten- nas no longer implied competence with the mainstream of electronics equipment. Second, there was something called "license deregulation." Modem tech- nology had made the stability of radio equipment so reliable that as far as the FCC was concerned, other than for the ship and aircraft services there was really no longer a need for a specially-licensed technician. So the FCC eliminated the requirement that only an FCC-licensed technician could make adjustments and repairs to transmitters: It became the re- sponsibility of the owners and operators of radio-transmitting equipment to ensure proper operation. (Although Congress implied that the FCC could recognize technician "certification" by industry- sponsored private organizations — and that agency has sent out notices about programs available — it officially recog- nizes no "private" certification of any kind.) Since an FCC license no longer re- llected the major interests of electronics, und since very few positions in the com- munications industry required an FCC li- cense, how, then, was an employer to evaluate a potential employee's technical know led tie and skill? CERTIFICATION FOR ELECTRONICS TECHNICIANS If you really have specialized knowledge and skills- 11 you know your stuff— you can become a certified electronics technician. W. CLEM SMALL GET For the seasoned technician, past em- ployment records may be ail the recom- mendation that's needed, but for the less experienced person it is usually a different and more complex situation. While it is possible for an employer to ask for tran- scripts of the applicant's trade-school training, many new technicians who want to work in communications have picked up their knowledge without going to a formal trade school: How are they to es- tablish their knowledge and competence? Certifications Often, employers will test job appli- cants, but if properly done, on-site testing can be a relatively expensive undertaking that often costs more than many small shops can afford to spend. One effective way to ensure the proper testing and eval- uation of potential employees is to use the certification procedures of the various professional organizations that have evolved to serve the communications and electronics industry. In fact, within the broadcast and telecommunications indus- try, most employers who formerly re- quired the FCC First-Phone now require (or accept) certification by a professional or industry-sponsored organization. The exact procedure used for the cer- tification of technicians depends on the particular organization. For example, one early approach was to consider a techni- cian's past FCC license level and perhaps his employment under that license. Both 52 C5B? '///orr/////f,j/£,/ FIRST CLASS • G* -sr.il Rfcrfiat ■ 1 1 p h G ft* C» rli flCR.1 *.• I Motm I m*tn MtM ftATC «' - 1 •- - ■■ ■ IS A UCEH5ED RADIO OPERATOR, iUfHOIHIte, SUBJECT TO ART SPECIAL ENDORSE W(N I PLACED NEREO*. TO 4P[ ■ « TC THE CUSSES OF LICENSED RADIO STATIONS fOR WHHlN THIS. CLASS OF LICENSE IS VALID UNDER THl ORDERS. tULIS J.*0 REGULATIONS OF THE FEDERAL COHHUNICAITONS COMMISSION. ANT STATUTE OF THE UNITED STATES AND AH* TMATT 10 WHICH THE UHJTED STATES 14 A rxWft. THIS LICENSE IS GRANTED UNDER THE AOTKDRI rF DF THE CCHHUFHCATICKS ACT OF ISJi, AS AM1H&ED. »"3 THE lERKS AND EQUDlTIONS THEREOF AND OF ALL LEGISLATIVE ACTS, EXECUTIVE ORDERS, *»Z TREATIES TO WHICH THE UNITED STATES IS SlGflATOKT, AHEr ALL OiDEftS, tULIS AMD B ECU | AT ION E OF THE FEDERAL COMMUNICATIONS COMMISSION, WHICH ARE BINDING UPON NA&IO OPERATORS, ARE HADE A PART hueot *s THoysn sh-cut-cally srr out in full herein, *FITNE» THIf 1FCEHSE NOR THE RIGHTS CE (111 TIES TQ< HEREIN i.H*LL RE ASSIGNED OH OTHERWISE Tr?ANSf EITREQ '0 AHT -OTHER PlRSON. ?«bni*rr 2Z. 197B RLACE *NO DATE Of IHLiAHGEi i«B fTKlClRCq, California DATE AHO TIME OF EH »IH A 1 IDH= f^bniRXy 52, 1933 jh.T T«REE O'CLOCK A.H..,, EASTERN IT SPECIAL EM &ORSEM EH T iatulif OJjrCW EXPIRED NOT VALID UNTIL SIGNED THIS WAS THE LEGENDARY First-Phone FCC license. Ho longer in existence, it attested to the holder's general technical competence. It was often a "ticket to success" in communications. ' V V v V'V V V V w V V ^ u V V u V V W V V V- >■ /fit fat tiff fw aw/ f/hcre/y o/ BEGIST£ftEO RADIOTELEPHONE OpEHATOR LICENSE [GvArf»l HtfO M h u riOni Cv jitacawl Thrr cirtifiti Ltiit the individual Fumtct intf oncjsbrd bt^ow ii i licensed radio operator a--d Is juthofpied eg opeta^e llctnud radiQ LUKDM for VrtliCh> llnS et«i Of llcenie li valid The #Uth«llY qraillc<! .1 lubptct 10 any tndVHTnrn.1 plACtd on trull licnrtK:. Thi auihof iiy g/antld ii i>» subject to Irvf wdors, rul« r md regulations 01 tht interftitionftJ Society of C»r1iFiKf ELKlTOFIJCI Technician! Rftd the EtllUUS ■ iha UoltBd StllM. The lltftiie may not be Ksigntd or iranifrrred to my QtliK oflnoo. It expirn it thfH o'clock AM EHtefn Sundard Tlnn« on Ihit dm* shown tw^aw. SVC HC^I WfliDhT Color Eyas ColChT ha.i Dji* of Birth PIkh dI I«wjom Expifi!!on Dau Lpcchh Numbec ifiify He! W<4 Without tKET 5iK SEVERAL PHIVATE CERTIFICATES are similar in appearance or format to the old FCC First-Phone license. the A/ational Association of /Justness And Educational fladio (NABER) and ihe So- ciety of Broadcast Engineers (SBE) have had certification programs that required prior possession of an FCC license as a basic requirement. Upon satisfaction of their requirements, a certificate that re- sembles the old FCC license is awarded to the applicant. On the other hand, various aspects of existing and emerging radio technologies such as cellular telephone, as well as the telecommunications skills needed since the breakup (deregulation) of AT&T, requires highly specialized knowledge, which is certified through special exams given by the National Asso- ciation of /?adio And Telecommunication Engineers (NARTE), which certifies on two levels: technician and engineer. Al- most without exception, NARTE cer- tification requires a combination of ad- vanced schooling and extensive experi- ence. For example, their lowest class of engineering certification requires either a two- or four-year engineering degree, or previous high-level technical certification plus two years of engineer-level experi- ence. The NARTE s minimum technician certification (Class IV) requires an exam- ination, while the highest (Class t) re- quires previous certification plus six years verifiable radio or telecommunications experience. CET Long before FCC deregulation, elec- tronics professionals recognized the need for certifying electronics technicians in troubleshooting consumer products, in basic logic circuits and industrial con- trols, and the safety and accuracy of cal- ibration for medical electronic instru- ments. As early as 1 965. the CET test used by the international Society of Cer- tified Electronics Technicians (ISCET) used exams that tested black and white television adjustments, audio speaker en- closures and adjustments, and the use of electronics test equipment. Nearly 20,000 technicians had passed those exams (out of about 70,000} even before the FCC deregulation. Persons passing the appropriate tests may first attain the apprentice electronics-technician certifi- cate, and then one or more advanced jour- neyman-level certificates. CERTIFICATION PROGRAMS Electrortic's Technicians Association 604 N, Jackson St. Greencastle, IN 46135 International Society of Certified Electronics Technicians 2708 West Berry St. Fort Worth, TX 76109 National Association of Business and Educational Radio P.O. Box 19164 Washington, DC 20036 National Association of Radio and Telecommunications Engineers P.O. Box 15029 Salem, OR 97309 National Institute for Certification in Engineering Technologies 1420 King St. Alexandria, VA 22314 Society of Broadcast Engineers P.O. Box 50844 Indianapolis, IN 46250 > c Q C ID 03 ~4 53 J z 3 r J .1 -j u 5 =r_ E Two organizations lhat offer a CET or C.E.T. testing program are ISCET and the Electronic Technician's Association (ETA). Options that are available from one or the other of these programs include most major areas within electronics tech- nology. Within the ETA program are the ad- vanced options of Senior C.E.T and Mas- ter C.E.T., which are available to persons with eight or more years of experience in die profession. Higher passing scores in a chosen option are required for the senior level than for the lower levels. The master option requires passing an examination that covers consumer electronics, com- mercial electronics, communications, in- dustrial electronics, computers, and bio- medical electronics. ISCET has two levels of certification. Associate C£T*s must pass an exam cover- ing basic electronics, circuits, semicon- ductors, test instruments, and basic troubleshooting. Technicians with four years experience can take the higher-level Journeyman exam at the same lime. They must be certified at the Journeyman level to use CET after their names. CET's are issued permanent certificates suitable tor framing and a plastic wallet card. Once certified as a CET or C.E.T., technicians arc eligible For membership in the parent organization, ISCET or ETA. Members receive books, magazines, re- prints, and regular technical material; may attend conventions and technical training programs; and receive discounts on books, tapes, and software. But the real benefit of certification is a growing awareness within the electronics industry that a certified technician is a person who has demonstrated considerable skill, un- derstanding, and competence in his or her tested areas. The FCC and CET The FCC has made no official sanction of any private-industry certification pro- gram. Public notices have been issued by the FCC to assist technicians in locating certification programs, but those have specifically stated. "The Commission does not approve, endorse, or officially sanction any private sector certification program..." However, in its Report and Order, docket 83-322. 49 Fed. Reg, 20658, the Commission did endorse the concept of private sector certification pro- grams as a possible substitute for Com- mission testing of commercial radio operators. The right certification It is reasonable to expect that, as more and more jobs require certification of some kind in lieu of the old First-Phone, we're bound to sec a plethora of private organizations offering their own version of private licensing. Bear in mind that certification that isn't specifically recog- PKKSIUtNT. NAUEK AUGUST 1. 1984 The National Association of Business and Educational Radio, Inc. Certifies that has demonstrated a knowledge of Ihe Federal Communications Commission's Rules and Regulations governing ihe Land Mobile and Private Fixed Radio Services and has shown a general comprehension of the theories of electronics and radio propagation. This individual is hereby recognized as a NABElK Certified Technician through a FEDERAL COMMUNICATIONS COMMISSION endorsed program. EVEN WHEN THEY DON'T RESEMBLE the First-Phone license, some private certificates such as this one state or imply endorsement by the FCC, although the FCC does not approve, sanction, or endorse any private program. International Society of Certified Electronics Technicians Associate Certified Electronics Technician be it known by these presents lhat p, ; .:v ... - thtti:: L-i. has succotsiuliy compiasid me Technical Tests and Ftequii ements g«,ng univeisal recognition tDf competence ability and knowledge as an Associate CeMitrtO Eleclionics Technician fills ceMiticnFe is ss'jed |Oin1ky by ILBtJUlli* Lie* vJI'lii...' Li, PRIVATE-SECTOR CERTIFICATION attesting to a minimum level of knowledge and skill ts available for various areas of electronics. It often serves as a "ticket to success." nized by employers is worthless. If you want a particular kind of job. say in cel- lular phone, or even broadcasting, check with some large operations and specifical- ly ask if they recognize or require private certification or licensing and, if so. from whom. If you choose to work in an area that requires private certification, bear in mind that as a general rule the higher the certificate for which you qualify, the greater the potential job opportunities. For more information on how to get certified in various electronic tech- nologies, you should contact the major private certification organizations listed in the box that can be found elsewhere in this article. Although those organizations are not-for-profit, they do have a reasonable fee for testing and processing. In par- ticular, we suggest you enquire as to what study guides they specifically recom- mend R-E 54 D '21 C~Z3 TRANSISTOR WE WERE HAVING TROUBLE FINDING AN exact replacement transistor while repair- ing a piece of equipment recently. Figur- ing thai an exact replacement was going to be impossible to hnd. wc began to discuss what to do. And someone pointed out that there were only two kinds of bipolar tran- sistors — NPN and PNP. Of course, values for various characteristics vary widely, even for a specific transistor; but in many circuits, a garden -variety device will work (and did in our case). Designing and repairing transistorized circuits is much simpler than you might suspect. A well-designed circuit has built- in tolerance, so it's probably not device- sensitive. The most important charac- teristics to consider when substituting de- vices or designing a circuit from scratch are operating frequency and power level. What follows is the design procedure we went through to solve an audio-gain problem. Try it when you need a little extra gain for that next audio project. An audio amp This particular project involved inject- ing the audio from a TV receiver into a stereo system. The audio-output portion of the TV-audio receiver was abandoned because of its poor frequency response and high distortion. Instead, we wanted to come right off the detector into a quality audio amplifier and speaker. So. after picking off the audio at a convenient point in the set (in this case, from a potentiome- ter), wc wanted to feed it to the auxiliary input of the stereo amplifier. The amplifier we used required an input of I volt rms, but a quick check with an AC VTVM indicated that our picked-off audio signal was only 0.1-volt rms. Ob- viously, an amplifier with again of 10 was needed. Scanning the literature on transistor amplifiers revealed that a common-emit- ter amplifier with a voltage-divider bias circuit would solve our problem nicely. Such a circuit is shown in Fig. 1 . Some of that circuit's characteristics include: mod- erate input impedance, moderate voltage gain, inverted output, and input/output impedance and gain that depend only slightly on transistor beta. There are, of course, several rules that must be followed in using a common- emitter amplifier, including: • With a positive supply use an NPN transistor. • With a negative supply use a PNP tran- sistor. • The supply voltage must not exceed the transistor's V CE rating. AMPLIFIER DESIGN JACK CUNKELMAN It's easy to design a simple transistor amplifier, Here's how. • The power-dissipation rating of the transistor must not be exceeded. • The beta of the transistor should be 100 or higher. In our example the following facts are known: • Our amplifier had a single-ended 12- volt power supply. • We need a voltage gain of 10. • The input impedance of the amplifier should be about 15K, the same as the potentiometer from which audio was taken. • Th e i mpedance of the ste re o am p I i he r 's auxiliary input is about 50K. As is the case in most circuit designs, a few facts are known, and the rest must be calculated or picked using a few "rules of thumb." We will learn how to make the calculations next. Doing the math For maximum undistorted output swing, we will make the quiescent collec- tor voltage 'A the supply voltage. See Fig, 2. The drop across R c must therefore be 6 volts. The value of R c , the collector load re- sistance, is chosen considering output im- pedance, gain, and collector current. If possible, the output impedance should be lower than the impedance of the circuit wc are feeding by a factor of 10 or more. Doing so will avoid circuit loading. So let's make R c equal to 4700 ohms, which is about 50K/10. > c G) C CO CO 03 -J 55 LISTING 1 10 CLS TO THIS IS";R1 20 REM TRANSISTOR AMPLIFIER CALCULATIONS 360 PRINT "CALCULATION OF THE INPUT AND 30 REM BY JACK CUNKELMAN OUTPUT CAPACITOR VALUES" 40 REM APRIL 19B6 370 INPUT "LOWEST FREQUENCY THIS AMP SHO 50 GOSUB 900 ULD PASS"jF 60 INPUT "SUPPLY VOLTAGE" ;V 3B0 CI = 1/(3.2*F*IZ) 70 PRINT "THE DROP ACROSS THE COLLECTOR 390 CI = CI * 1E+6 RESISTOR ="V/2"V0LTS" 400 C2 = 1/C3.2*20*Z) SO INPUT "INPUT IMPEDANCE OF THE FOLLOW I 405 C2 = C2 * 1E+6 NG STAGE(OHMS) ";Z 410 IE = VE/RE i RJ ■ .03/IE 90 RC = Z/10 420 A - RC/RJ 100 PRINT "COLLECTOR RESISTOR, f?C SHOULD 430 C3 - 1/<6.2*F*RJ> BE "RC" OHMS" 440 C3 - C3 * 1E+6 105 INPUT "THE CLDSEST 5*/. RESISTOR VALUE 500 CLS TO THIS IS"jRC 510 PRINT "PARAMETERS FOR A COMMON EMITT 110 IC - (.5*V)/RC ER AMPLIFIER STAGE" 120 PRINT "THE COLLECTOR CURRENT IS"IC * 520 PRINT 1000"MA" 530 PRINT "SUPPLY VOLTAGE ... 130 INPUT "DESIRED VOLTAGE GAIN"}G . "V" VOLTS" 140 RE = RC /G iR* ■ CHR*<32) 540 PRINT "COLLECTOR RESISTOR (RC) 150 PRINT "THE EMITTER RESISTOR FOR THIS . "RC'OHMS" GAIN IS "RE "OHMS" 550 PRINT "EMITTER RESISTOR <RE> .... 160 IF RE<=39 OR RE =>100i THEN 170 ELSE . "RE "OHMS "R* ISO 560 PRINT "BIAS RESISTOR <R1> 170 R* - CHRSC42) ."R1"0HMS" ISO INPUT "GERMANIUM (G) OR SILICONE (8! 570 PRINT "BIAS RESISTOR <R2) TRANSISTOR TYPE"sT* ,"R2"0HMS" 190 IF T* »"G" THEN 210 5B0 PRINT "INPUT CAPACITOR (CI ) 200 IF T* ="S" THEN 220 ELSE ISO ."C1"MF" 210 J = .2 :GOTO 230 590 PRINT "OUTPUT CAPACITOR (C2) . . . . 220 J - .6 . "C2"MF" 230 VE = IC * RE 600 PRINT "VOLTAGE GAIN 240 PRINT "THE DROP ACROSS THE EMITTER R . "G ESISTOR IS"VE"VOLTS" 610 PRINT "TRANSISTOR BETA 250 VB » VE + J . "B 260 PRINT "THE BASE VOLTAGE MUST BE"VB"V 620 PRINT "LOW FREQUENCY LIMIT QLTS" ."F"HZ" 270 INPUT "WHAT IS THE DESIRED INPUT IMP 630 PRINT "EMITTER BYPASS - "C3"MF FOR A EDANCE FOR THIS STAGE"; IZ GAIN OF "A 230 R2 = IZ*RE*100/< <RE*100)-IZ> 700 INPUT "RUN AGAIN.. Y OR N";R* 290 PRINT "THE BIAS RESISTOR, R2 IS"R2"0 710 IF R* ="Y" THEN 10 HMS" 720 IF R* = "N" THEN END ELSE 700 300 INPUT "THE CLOSEST 5% RESISTOR VALUE 900 PRINT "CALCULATIONS FDR A COMMON EMI TO THIS IS";R2 TTER AMPLIFIER STAGE" 310 VD = V - VB : 12 = VB / R2 910 PRINT 320 IB - IC/B 1000 INPUT "TRANSISTOR BETA IF KNOWN (0 330 Rl = <V - VB1/CIB + 12) . IF UNKNOWN)" ;B 340 PRINT "THE BIAS RESISTOR, Rl IS"R1"D 1010 IF B = THEN B = 100 HMS" 1020 RETURN 350 INPUT "THE CLOSEST 57. RESISTOR VALUE CO g z O cr i- o LL _l LU o D < DC Collector current. I c , is equal to 0.5 V cx VR r . or 6/4700 = 1.28 mA. That current is certainly low enough that we will not exceed any collector-current rat- ings, so let's go on. To achieve maximum stability, the emitter resistor should be in the range of 40 to 1000 ohms. Voltage gain (A v ) = R ( ./R, : . so R [; = R c -/A v In our case R,. equals 4700/10. or 470 ohms. That falls within the range of acceptable values. The current through the emitter resistor consists of the collector current plus the base current. The base current here is sig- nificantly smaller than the collector cur- rent, so it can be ignored for the next calculation. The voltage drop across the emitter re- sistor = I c X R E , or 1.28 mA X 470 ohms = 0.602 volts. The base voltage must exceed the emitter voltage by 0.6 volts for a silicon transistor and by 0.2 volts for a germanium transistor. We'll use a silicon transistor in our circuit, so the base voltage must be 0.6 -I- 0,602 = 1.202 volts. The input impedance of the circuit equals R2 in parallel with the emitter re- sistor times beta: input impedance will vary with the transistor's beta. For our example, assume we are using a transistor with a beta of 100. We want the input impedance to be about 15000 ohms. Solv- ing for R2. we find: Z, N = (R2 x R e x p)/[R2 + {Re x p)] R2 = (Z, N x R E x (J)/[(R E xp)- Z IN ] R2 = (15000 x 470 X 100)/[(470 x 100) - 15000] R2 = 22,030 ohms We can use a 22K resistor. In general , if input impedance is not critical , for max- imum stability R2 can be 10 to 20 times R E . The drop across R2 must be 1.20 volts, so the current through R2 is 1.20/22,000, or 0.054 mA. Therefore. Rl must drop the rest of the supply voltage, which is 12 — 1.20 = 10.8 volts. "The current flowing continued on page 77 56 ROBOT The robot's command language Part 9 now that we ve As- sembled the robot's hardware, it's lime to dig into the soft- ware. In this article we'll describe the R-E Robot's command language, RCL (Robotic Control Language). It's an easy- to-learn and easy-to-use language written in FORTH. Don't be scared by FORTH; you can use RCL without being an expert at programming in the language. And, as you leam RCL, you'll leam (painlessly) the basics of how FORTH works, so that, if you want to, you can go on and learn the language itself. To give you a chance to see RCL in action, we'll present a robot- based mail-delivery system. You can study our program to learn how RCL works, and you can also use it as the basis of your own program. How difficult is RCL? Not very. For example, suppose you wanted the robot to move in the forward direction 3 .4 feet at a speed of 2 miles per hour. You would simply type in the following code: RERB 2 MPH 3.4 FEET FORWARD RCL includes commands to move the robot forward and backward, to turn left and right, to move its manipulator up and down, and to open and close a gripper. You can combine a sequence of com- mands and store them for execution at a later time. In addition, commands can also be executed immediately from the keyboard. Real-time control The R-E Robot consists of a computer- controlled set of electromechanical de- vices. The assembly is broadly known as a motion-control system . Real-time motion control requires real- time sensing and processing. One way to ensure proper sensing and processing is to force the computer to execute a control loop at regular intervals. That control loop will be the computer's highest priority. Everything else the computer does will be secondary, and it will have to do those other things as it finds time. A simple way to implement the control loop is to have a clock IC generate an interrupt at regular intervals. Each time the clock interrupts the microprocessor, it will execute the control loop, and then it will return to whatever it was doing before the interrupt occurred. The amount of time the computer spends executing the control loop must be less than the time interval between interrupts. RCL basics The software that controls the robot is built up layer by layer. The most primitive words must be defined first; more -com- plex words are defined using the pre- viously defined words; at the top level are the RCL words that make motion control easy. As each word is defined it can be tested and debugged. When it is debug- ged, the next layer may be defined. Notice that you are defining words, rather than writing a program, as with most computer languages. That's not just a matter of semantics; it's also a way of looking at a programming problem. The problem can be broken down into a series of smaller problems, and then those prob- lems can be broken down further, and so on, until you have a set of problems that can be programmed. Each little problem becomes a FORTH word, which in turn becomes part of another FORTH word, so that eventually all we have to do is say something like TURN-LEFT The real-time control portion of RCL consists of the hardware interface, inter- rupt control, following-error monitoring, velocity control, and position control. > c Q C w 57 CO o z O □c O LU 6 Low- 1 eve I words The most-primitive words deal with the robot's hardware: turning the motors on and off, setting the direction in which each motor rotates, and enabling the speed-control circuits. To eonlrol the hardware, values must be written to and icad from various registers on the robot's control board. Those registers are read and written using the microprocessor's 1/ O statements (IN and OUT). In RCL, to write an eight-bit value to an output port, the word PC ! is used: PC! (value port — -) That statement specifies thai value is to be output to I/O port part. A word about notation is in order. The stack diagram, enclosed in parentheses, represents the parameters required by the word PC! In- put parameters appear to the to the left of the dashes, and output parameters appear to the right. In this case there are no output parameters. FORTH words in general (and those of RCL in particular) make extensive use of the stack, both for parameters supplied to a word, and those that it may produce. The lop of the stack is always the parameter furthest to the right. In the preceding ex- ample, the slack diagram shows that the value to be written must be pushed on the stack followed by the port to which it is to be written. The word PC! removes these parameters from the stack, uses them, and leaves nothing on the stack. Other words may leave one or more values on the stack . Motor-control words Several words operate the speed-con- trol circuits and the relays. For example, ENABLE and DISABLE write an appro- priate value to turn on or off a particular function of the hardware. STOP-LEFT, STOP-RIGHT, and STOP use DISABLE to turn the relays off. FORWARD, RE- VERSE. CW, and CCW enable the proper relays to allow the motors to turn in the desired direction. CW and CCW allow turns to be made by enabling the wheels to turn opposite to each other. GO and COAST enable and disable the speed- control circuits and the motor-drive cur- rent as well. Speed control Hardware on the control board is re- sponsible for controlling speed (accelerat- ing and decelerating). The hardware makes the software system much simpler than it would be if the software were re- quired to maintain speed alone. The phase-locked loop on the control board maintains the desired motor speed under varying loads. The software only has to set the speed, and to accelerate and decele- rate the base unit. The speed at which each motor runs is determined by the frequency of a signal that is generated by counter of the 8253 timers. Setting the number of counts in the counter determines the period of a squarewave output. The phase- locked loop circuitry responds to the frequency corresponding to that period. The frequency of the signal applied to the 8253 's on the motor-control board is the 2-MHz system clock divided by 16, or 125 kHz. Therefore a count is generated every 8 microseconds (1/125,000). The 8253 is programmed to generate a square- wave whose period corresponds to the val- ue loaded into the counter. So, if the counter is loaded with the value 125, the total period would be 125 x 8 microse- conds, or I millisecond, which corre- sponds to a frequency of 1000 Hz. With a 500-count-per-revoIution en- coder, the motor speed would be 1000/500 = 2 revolutions per second, or 120 rpm. The counter can be loaded with any value between 1 and 65 ,536 (0 actually), corresponding to frequencies ranging from 125 kHz to just under 2 Hz. Interrupt control Motor speed must be updated many times per second to produce smooth ac- celeration and deceleration. The update rate is set by the interrupt-control routines to 100 times per second (i. e., there are 10 ms between interrupts). The 80188 micro- processor has three built-in timers that can generate interrupts. Timer is used by the BIOS and the DOS to maintain a time-of- day clock. The BIOS is set up to generate interrupt OlCh every time timer counts down to 0. If we change the count value in timer we can use it to generate the motor-control interrupt. However, the time-of-day clock will count in 10-millise- cond periods instead of the usual 55-milli- second periods, so a set of time-of-day words will have to be defined for the new rate. In addition, we'll have to install a new BIOS-level interrupt handler to main- tain compatibility with MS-DOS. First of all, we must define the interrupt routine we want to execute. Then we can install that routine so that it is executed each time the interrupt is generated by the timer. The word 1NT-OFF disables interrupt generation by the timer so that we can change the interrupt vector, or disable it. INT-ON turns timer- interrupt generation back on. SET-TIMER takes a count that sets the period for the timer. The input frequency to the timer is 2 MHz/3, yield- ing a period of 1.5 microseconds per count. If the count is set to 6667, the timer will countdown to every 10 milliseconds and generate an interrupt. GET — CS is a special word that is used to return the code segment in which the FORTH system is executing. SET-INT sets the interrupt vector to the word we want to execute each time the interrupt is generated. INSTALL performs all the tasks neces- SOFTWARE SOURCES Micro K Systems (15874 East Hamilton Place, Aurora, CO 80013. 303-693-3413) will provide the following: Commented source code in RE-robot disk format, $2.00. Printed source-code listing, $15.00. Two 27128 EPROM's with source screens (and without comments) for the RE Robot, $39.00. With EPROM's you won't need a disk drive, but you should also obtain the printed listing to read the comments. The Laxen and Perry F83 Model disk with full source code and met- acompiler for customizing F83, in MS- DOS 360K format, for a PC compatible computer, $25.00. (Very useful for learn- ing FORTH if you already have a PC.) All orders must be prepaid. NO COD's. In- clude $3.00 for shipping with each order. Additional source code and applications will be available from Micro K Systems. Contact them for more information. sary to link a new interrupt handler into the microprocessor's interrupt vector in low RAM. After executing INSTALL the interrupt-control word will be executed every 10 milliseconds, and will continue to do so until the system is turned off, the interrupt is disabled, or a new interrupt routine is installed. Position-counter words The hardware position counters must be initialized by the robot's software. In addition, the position counters are only 16 bits wide, so the robot won't move very far before the counters overflow. So it's necessary to extend counter length with software. If we look at the counters often enough, they will not overflow. The soft- ware maintains a 32-bit position counter. Because the counter routines must be executed many times per second, the time required to execute those routines is im- portant. So all counter routines (and sever- al others) have been written as CODE words. To experiment with those words, you'll have to know 80188 assembly-lan- guage programming. The high-level words for reading the counters are ?CNTl and ?CNT2 to read the positions of motor 1 and motor 2, respectively. The hardware causes the 16- bit counters in the 8253 IC's to decrement for each encoder count that is in the proper direction. The difference between a motor's forward and reverse counts gives the absolute position of the motor. Following-error words To detect a problem with the motors, it is necessary to compare actual speed with expected speed. If the two differ by more than a small percentage, an overload con- dition exists, so the motors could overheat and be destroyed. The following-error words constantly monitor the motors and detect a stalled motor by comparing the 58 current motor position with the expected position. If the difference is too great the motors are turned off immediately. This also means that if you specify a value of acceleration that is too high, a following- error will be detected, and the motors will be shut down. Numeric input FORTH normally works with I6-bil signed integers. Such numbers can range in value from -32768 to +32767. In addition, a decimal point may be included anywhere in a number and FORTH will treat it as a signed double-precision integ- er with a possible ranee of -2,147.483,648 to +2,147,483,647. The position of the decimal point is kept in a system variable, DPL. If a number without a decimal point is entered, the system sets DPL to — I . If a number is entered with a decimal point, DPL will contain the position of the decimal point relative to the least significant digit en- tered. A number may have a maximum of four digits to the right of the decimal point. The FORTH system converts the input number to a signed integer repre- senting the integer part and a signed integ- er representing the fractional part. The pair of single precision numbers each car- ries a sign bit; the numbers can be used alone or together. Table I illustrates how various numbers are stored. Keep in mind the fact that the decimal -point position stored in DPL is correct only for the last number entered by the user from the keyboard. Numbers compiled into a definition do not affect the value of DPL after compilation. You must be in the decimal base (base 10) when entering numbers with decimals. The word FIXED converts the last number input to an integer and a fraction. FIXED gets the value from DPL and puts it on the stack, then it calls (FIXED). We defined the separate word (FIXED) to do the actual conversion, because it can be made more general — it can convert any number, even if it was not entered from the keyboard. EXTRACT strips the fraction digits from the number one by one until all have been removed. That leaves the integer part of the number on the TOS (Top Of Stack) with the digits beneath it. The digits are reassembled into a single number with BUILD. SCALAR produces a value that is used to adjust the fraction to the proper range. If the unsealed fraction is 9, we need to know whether it is 9000/10,000. 9/10,000. or another value. The word FRACTION takes a fraction, an integer, and a multiplier and creates a double-precision integer. So the value -932.015 converted by FIXED is a frac- tion and an integer. Taking these two numbers and a multiplier of 1000 would give us the double precision number -932015 as follows: TABLE 1— NUMERIC STORAGE Input Value Size DPL 725 725 16 -1 -1 -1 32 1.2 12 32 1 -9.999 -9999 32 3 38.04 3804 32 2 932.015 FIXED 1000 FRACTION. FRACTION is used by many other words to convert values for internal use. User-input conversion words Several words convert user-input values to more basic units the hardware can use for the move commands. Distances are entered in units of INCHES, FEET, MILES and DE- GREES. INCHES takes the value spec- ified and converts it to internal form. The input value and a scale factor are saved for later conversion. FEET takes a distance in feet and MILES takes a distance in miles. The scale factor is set appropriately for each word in terms of the number of inches each word represents. DEGREES calculates how far each motor must move to make the specified turn. Speed can be entered in miies per hour by using the word MPH, inches per sec- ond by IPS, feet per second by FPS, and feet per minute by FPM. Each of those words stores the value and an appropriate scale factor for later conversion. G converts the input value (in terms of the acceleration due to the earth's gravity, i.e., 32.2 ft/sec/sec) to a count that is used to accelerate or decelerate the motors, if necessary, each time speed is updated by the interrupt routines. Motion To move from one point to another, the motors must be accelerated and decele- rated. By allowing the user to set a value for acceleration, deceleration, and max- imum speed, the behavior of the robot can be controlled precisely. Before a move is actually made, the software does a series of calculations to determine the top speed that can be at- tained, and the positions at which acceler- ation should end and deceleration should begin in order to attain a trapezoidal ve- locity curve, as shown in Fig. I. Calculated speed may be less than de- sired speed, but that is not a problem for short moves. Maximum speed will be used for moves that are long enough to allow the motors to accelerate to their maximum velocity. For short moves, ac- celeration is more important than max- imum speed. To perform a move, breakpoints on the trapezoidal velocity curve must be found. The points where acceleration ends and deceleration begins, as well as the end point position, must be calculated. The robot is a speed-controlled system, so the acceleration and deceleration breakpoints must be used to calculate what speed will be achieved by accelerat- ing at the specified value of acceleration to the breakpoint position. That new speed is saved with the breakpoint posi- tion. The same values of speed and dis- tance are used to calculate the breakpoint where deceleration is to begin. Trapezoidal velocity control To perform a move, the robot must be accelerated from a speed of zero to top speed, and then decelerated at the appro- priate point to arrive at the desired posi- tion. The simplest system would just set the speed of the motors, turn the motors on until the end point was reached, and then turn the motors off. That type of approach assumes instantaneous acceler- ation and deceleration, but in an actual F QSIT 0N- ^v \ ELOC ITV- "V \ V \ V V u> ACCEtERATION \ DECEtERATION ti. ■_■: : ; .- \ V \ TIME FIG. 1— ACCELERATION AND DECELERATION BREAKPOINTS must be calculated In order to move the robot from one point to another. > C a c CO to -J 59 o z o a: H O LU o < Q. system it's not practical. Therefore, we have to take into account the acceleration that actually can be achieved by the sys- tem. In practical terms, acceleration might be a fraction of G, or it could be several G's, depending on the size of the motors in relation to the size of the load. To accelerate and decelerate the robot, velocity actually must be changed many times per second. In general, the robol starts with a velocity of zero and then accelerates at a constant rate to the top speed. Then it must decelerate at a con- stant rate until it stops at the final position. The velocity-versus-time profile is also shown in Fig. I, but superimposed on the velocity trapezoid. Note that the position profile is not simply a straight line. In terms of calculus, position is the integral of speed over time. The basic equations of motion are as follows: V = Vp + AT D = V T + V4AT 2 where V stands for velocity, A for acceler- ation, T for time, and D for distance. V Q refers to starting velocity. From the previous equations we can derive an equation that describes the dis- tance required to accelerate from one speed to another: D = (V2 - V 2 ) / (2A) We can use that equation to compute the distance required to change speeds. For a short move, the distance required to accelerate to the desired speed and then decelerate to a stop may exceed the dis- tance to move. In such a case, decelera- tion must begin at some speed less than maximum. The word DISTANCE takes the origi- nal speed and the desired speed (both in rpm) and calculates the distance in inches that will be required to change speeds. The word COUNTS changes the distance from inches to position-encoder counts. The word EXPECTED converts the user- input distance to position-encoder counts. The word SPEED converts the user-input maximum speed into rpm. The word BREAKPOINTS calculates the positions on the velocity trapezoid to stop accelerating and begin decelerating. The acceleration and deceleration seg- ments can't be more than half the total move distance, so the distance to acceler- ate from to the input speed is calculated and compared to half the move distance. The minimum of these two values is then used as the acceleration distance. The breakpoint positions are saved in arrays for use during the move. After the robot starts moving, the breakpoint positions are compared against the current position every time the control loop executes to determine when acceleration should stop and deceleration should begin. If the move distance is long enough, there will be a period during which the motors run at maximum speed. For a short move, acceleration will stop before maximum speed is attained, and deceleration will start immediately after acceleration stops. Command language The RCL includes a simple command set to allow movement of both the base unit and the arm. The base-movement commands allow forward and backward motion, and left and right turns. Maximum speed, acceler- ation rates, and move distance may all be altered by user input. After each move is complete, a new move command can be executed. By denning FORTH words we can chain several move commands to- gether in a motion sequence. We'll dis- cuss such a sequence shortly. The arm commands move the arm up and down, and open and close the jaws. Command syntax In general, a command consists of a device name, a speed value, a distance value, and the command: [DEVICE] [n SPEED] [n DISTANCE] COMMAND where bracketed quantities indicate op- tional values that will be: the value entered with the command; the last value if a new value is not included; or a default value if this is the first time the particular command is issued. The value of n de- pends on the command. DEVICE may be RERB for the base unit or ARM for the arm unit. Base commands The general syntax for the base-move- ment commands is as follows: [RERB] [n SPEED] [n DISTANCE] COMMAND COMMAND may be one of the follow- ing: FORWARD, BACKWARD, LEFT, or RIGHT. SPEED may be one of the following: MPH, IPS, FPSorFPM. DIS- TANCE may be one of the following: INCHES, FEET, MILES or DEGREES. The command G is used to set the ac- celeration constant used to change speed; the constant is expressed in G's of acceler- ation. Any acceleration may be specified, up to the maximum acceleration the sys- tem can achieve. The acceleration may be specified in a separate command. Arm Commands The basic syntax for the arm- movement commands is as follows: [ARM] [n DISTANCE] COMMAND COMMAND may be one of the follow- ing: UP, DOWN, OPEN, or CLOSE. DfSTANCE may be INCHES or FEET. DISTANCE is the amount specified in the COMMAND direction relative to the cur- rent position. The example program shown in Listing I illustrates how you can combine several RCL commands to cause the robot to tra- verse a square. The sequence first sets the acceleration constant to 0,1 G. Then the RERB device (i. e., the base) is selected to move at 25 .5 inches per second. Then it moves 3.5 feet forward and makes a left turn. The latter actions are repeated three times so that the robot ends up where it started. Here's a short routine that moves the arm down and then back up: ARM 3.1 INCHES DOWN 2 INCHES UP By defining FORTH words we can create macros to perform various func- tions. For example, Listing 2 shows a macro that will cause the robot to traverse a box of any size. Example program Now let's show how the robot could be used to collect and deliver office mail. Figure 2 shows the office layout that we will use in the example program. Trays for incoming and outgoing mail are attached to the robot. The overall sequence of operations goes like this: The robot starts from a "nest," and travels around the corridors, waiting at several locations for people to retrieve and deposit mail and then returns to the mail room. We defined several low-level FORTH words for the program. To allow the robot to wait for different time periods, we de- fined several words to execute time de- lays. See Listing 3. The first is MS, which waits for the specified number of millise- conds. The next is SECONDS, which LISTING 1 .1G ( 3.22 ft/sec/sec) RERB 25.5 IPS 3.5 FEET FORWARD 90 DEGREES LEFT 3.5 FEET FORWARD 90 DEGREES LEFT 3.5 FEET FORWARD 90 DEGREES LEFT 3.5 FEET FORWARD 90 DEGREES LEFT uses MS to delay the specified number of seconds. The last is MINUTES, which uses SECONDS to delay the specified number of minutes. Next we define several words for con- venience and to improve the readability of the source code. The robot will announce its arrival at each place it stops. That is done by sounding a beep. The word AT- TENTION generates the beep. WARNING, sounds several short beeps. It is used to avoid running over anyone when the robot is ready to move. Since all the turns in our model office arc at right angles, it's convenient to de- fine left and right 90° turn words, TURN- LEFT and TURN-RIGHT When the robot starts its trip it must back out of the continued on page 80 60 A NEW KIND OF MAGAZINE FOR ELECTRONICS PROFESSIONALS IBM's N€W PS/2 Great graphics, super speed D€SIGN PC BOARDS ON VOUR PC New programs make it easy -S*L:?^ r x- ■::■-■.'■•.■:"'■'""'■ ■;"■•'■■.■■•■ - ■ ■ EU< ' V si«?feEi GERNSBACK PUBLICATION ' ■ Contents AUGUST 1987 Vol. 4 No. 8 67 MICRO-FLOPPY RETROFIT Your PC can read 3Vs disks with this simple upgrade. 69 DESIGNING PC BOARDS ON YOUR COMPUTER Smartwork, AutoBoard, and other PC- based CAD packages. Computer Dices? Larry Stickler, EHF, CET: publisher & editor in chief o z o cc o LLI I tu 6 a < 62 63 EDITORS WORKBENCH Hardware: The new IBM's (Models 30 and 50) Software-. Memory Minder disk drive analyzer RS-232 network program Art Kleiman, editorial director Brian C. Fenton, managing editor Jeff Holtzman technical editor Byron G. Wels, associate editor Carl Laron, associate editor Robert A. Young, assistant editor Teri Scaduto editorial assistant Ruby M. Yee, production director Karen Tucker, production advertising Robert A. W. Lowndes, production associate Marcella Amoroso production assistant Andre Duzant, technical illustrator Jacqueline P. Cheeseboro circulation director Arline R. Fishman, advertising director ComputerDigest Gernsback Publications, Inc. 500-B Bi-County Blvd. Farmingdale, NY 11735 ADVERTISING SALES 516-293-3000 Larry Steckler Publisher NATIONAL SALES Joe Shere 1507 Bonnie Doone Terrace Corona Del Mar, CA 92625 714-760-8967 Cover Photo by Jeff Holtzman and Andre Duzant EDITOR'S WORK- Bench 68000 UPDATE We've just finalized arrangements with Peter Stark, a long-time member of the microcomputing community to do a series of articles that will, be of great interest to anyone interested in Motorola's 68000 fam- ily of microprocessors, and to anyone who wants to learn about computer-system de- sign from the ground up. The series will center around a gradually upgradable CPU board that has been custom-designed spe- cially for readers of ComputcrOigcst. A minimal system can be brought up for about $200; it requires only a serial ASCII terminal or any personal computer and a communications program to operate. The computer can be populated on- board to include one megabyte of RAM, floppy-disk controller, battery- backed clock, Winchester interface, serial and par- allel ports, and more. It will also include 3-5 IBM-compatible expansion slots, in which you can pi ug a monochrome ISM PC display adapter In addition, the motherboard will accept an IBM PC keyboard. (Of course, it will also accept low-cost clone compo- nents as well.) Using a PC display adapter and keyboard will allow you to easily create a low-cost stand-alone development sys- tem The bare-bones system will include an EPROM-based monitor program called HUMBUG, which derived its tongue-in- cheek name from a series of different BUG programs, all of which were based on Motorola's original MIKBUG program, which was used in early 6800 (hundred, not thou- sand!) machines. HUMBUG has a number of commands for examining and displaying memory etc. In addition, we hope to in- clude a small version of BASIC in EPROM. The expanded computer will run the SK*DOS operating system, and possibly others. The author of SK*DOS also happens to be the author of the series of articles, so you'll get a unique first-hand opportunity to learn about operating-system design. SK*DOS includes a 68000 assembler, a line editor, a 6809 emulator, floppy- and hard- disk support, extensive file-manipulation facilities, etc. As for the MC68000 computer we pre- sented in the March and May issues this year, we should have the promised informa- tion packet ready by mid to late summer In addition, Peter Stark has adapted SK*DOS to run on the MC68000, although no formal system of distribution has been set up. We should point out, however, that the new (and as yet un-christened) machine will have better local support and distribution. All in all, we're very excited about this project; we hope to begin the series in October or November For more informa- tion, check our BBS (516-293-2283) occa- sionally, and watch these pages for announcements of progress. IBM'S NEW MODEL 30 AND MODEL 50 PC'S In case you missed it, IBM introduced four new personal computers last spring. They go by the name of Personal System/2, al- though only the three high-end machines (the Models 50, 60, and 80) have the new high-speed (and incompatible) Micro Channel bus, and only they will be able to take advantage of the new operating system OS/2, which we'll be lucky to see by early next year However, the low-end machine (the Model 30) is not without merit; we examined one, and a Model 50. All aboard The new low-end machine can be view- ed as a souped- up PC or XT, depending on whether you get it with two floppy-disk drives or a hard disk and a single floppy It has a bus that is compatible with the old bus, and it's a fast (8 MHz) 8086-based machine that contains everything on the system board that you normally must add via expansion cards: 640K of RAM, serial and parallel ports, keyboard and mouse connectors, battery- backed clock, and vid- eo adapter See Fig. 1. Other than the com- pact, lightweight system unit, the only thing you need to get a Model 30 running is DOS 3.30 and a monitor The video hardware is downward-com- patible with the CGA (contrary to our re- port last month), and has f^vo new modes of its own, including a stunning 256-color mode that allows you to create images like that shown on this month's cover (page 61). The other new mode provides 640 x 480 resolution in two colors, which should be great for CAD applications. The MCGA (Multi-Color Graphics Array) is not com- patible with Hercules or EGA standards, but it may be upgraded (via a plug-in card) to the VGA (Video Graphics Array) video adapter, which we discuss below, that is standard with the other PS/2 machines. The VGA is EGA-compatible. The Model 30 comes with a disk-based set-up/tutorial program that allows you to set time and date, park the hard-disk heads for moving the system, etc. The tutorial is extremely well-done, both in terms of the information presented and in the way it is c presented. The graphics in the tutorial are -h simply stunning,- they drew numerous oons S and aahs from our co-workers. The manual ^ > c Q 63 S087 MATH COPROCESSOR 8237A-5 DMA CONTROLLER SYSTEM GATE ARRAY ;> 8086 CPU n c I/O SLOT 1 I/O SLOT 2 I/O SLOT 3 MONITOR BEEPER VIDEO [ VIDEO MEMORY [ SUPPORT I/O GATE ARRAY PORTS • V.V.V.V.V.W • SERIAL CLOCK SYSTEM riMER DISK BATTERY FLOPPY ooooooooooooo oooooooooooo HARD PARALLEL FIG.1 el; in the high-res mode, each bit represents one pixel. Model 30 memory mapping According to the Model 30 Technical Ref- erence manual, the BIOS can detect the presence of an alternate video adapter. When it does, it will disable the on-board MCGA and use the alternate adapter. However, the manual does not specify what type of adapter may be used in that way So we don't know at present whether Hercules, EGA, and other adapters will function in the Model 30. But you can add the IBM PS/2 Display Adapter, which brings VGA-style graphics to the Model 30, as well as to the PC and XT models. The Model 30s 640K RAM has been im- plemented as follows. The first 128K con- sists of four 64K by four-bit and two 64K by two-bit DRAM's, all of which are soldered to the motherboard. The next 512K consists of two 256K by nine-bit plug-in SIP RAM modules. Those modules are mounted on a slant; they're visible at the right side of the system unit in Fig. 2. A special register (accessible at I/O port 6Bh) allows each 64K segment of memory from 40000h to 9O000h to be disabled in case of conflict with memory on an expan- sion card or hardware error In addition, a special bit in that register apparently allows one of the upper banks to be re-mapped to the lower 128K segment of memory in case there is a hardware problem there. The BIOS POST (Power-On Self Test) handles those duties automatically w o z O oc H o LU —1 LU 6 Q < IT FIG. 2 is a slim booklet that will neither intimidate the novice nor bore the expert, In our tests, we found no hardware or software incompatibilities. Our test unit ran an Ethernet adapter card and a 68000 co- processor card without a hitch. Tested soft- ware includes: AutoCad 2.6, WordStar 4.0, Dr Halo II (version 2.15, specially for the PS/2 line), SideKick 1.56b, Direc-Link, Brooklyn Bridge, Best Friend, PC ED, and numerous small utilities. The MCGA The Model 30s video adapter provides better text quality than the old CGA, be- cause each character is now displayed in an 8x16 box, rather than the CGA's 8x8 box. However, the screen still flickers when in the text mode. As many as four character fonts may be stored in the OAOOOOh seg- ment of RAM (formerly used by the EGA); one or two active fonts may be loaded and stored in a separate 8K static-RAM character generator DOS 3.30 uses the new font ca- pability to provide greater support for for- eign languages; the new capability should also ease implementing any scientific and engineering word-processing programs. The OBSOOOh area of memory is still used as a video buffer, with characters and their attributes occupying alternate bytes of memory In graphics modes, OBSOOOh is still used for storage in the old CGA-compatible modes,- in the new 256-color and 640 x 480 modes (11 and 13, respectively), the video buffer begins at OAOOOh. In the 256- coior mode, each byte represents one pix- Model 30 hardware notes The Model 30 has three horizontally mounted expansion slots; they're visible at the rear left in Fig. 2. The edge connectors for those slots are mounted to a board that in turn plugs into an edge connector on the motherboard. The expansion-slot board also carries the clock/calendar's backup battery,- that battery is soldered to the board, and at present IBM only plans to replace that board as a unit when the bat- tery wears out. The BIOS now supports four serial ports; previous machines officially supported 64 + NOT AVAILABLE * +NQ HARD DISK FLOPPY BEAD \ ■¥■ \ FLOPPY WRITE \ HARD READ HARD WRITE " IBM PS 2 MODEL 30 FLOATING POINT MATH INTEGER MATH IBM PS/2 MODEL 50 FIG. 4 FIG. 5 only two. The parallel port is now bi-direc- tional, so you can connect the parallel ports of two machines together and exchange data between them. In fact, IBM is selling a program/cable combination called the DataMigrationFacility(DMF)thatall ows you to do exactlly that. The DMF could be es- pecially useful in transferrins data from an old-style machine. The keyboard and mouse ports are elec- trically interchangeable-either keyboard or mouse may be plugged into either port- the BIOS separates keystroke scan codes from Mouse codes. All the I/O connectors are soldered to the motherboard. No external disk-control- ler cards (for hard or floppy disks) are nec- essary The_disk drive handles 720K 3Vs" disks, as used in the IBM PC Convertible and many other portables. The power supply is rated at only 70 watts, but that should be sufficient for most users. In addition, sur- face-mount technology is used extensively as shown in Fig. 3. The Model 50 The Model 50 can be viewed as a hybrid of an XT and an AT, with the Micro Channel bus (three slots) and OS/2 compatibility thrown in forsood measure. The model 50 has a 10-MHz one-wait-state 80286 micro- processor, which is faster than the AT's mi- croprocessor,- but it has a relatively slow, relatively small (20 megabytes) hard-disk drive like the XT The floppy-disk drive can read the 720K format used by portables and the Model 30; it also can read and write a new 1.44- megabyte format. You cannot format a 720K diskette for 1.44-mega byte use; special dis- kettes are required. The Model 50 also in- cludes a megabyte of RAM, and a full complement of I/O ports. We tested the Model 50 and found it to be quite fast. See Fig. 4 for a speed-com- parison chart. The Model 50 ran all the soft- ware we tested it with: WordStar 4.0, Dr Halo II version 2.15, numerous system util- ities, including a special communications program that manipulates the serial port directly — and everything we tested worked without a hitch. Of course, we couldn't test any expansion boards, be- cause none are available yet. The VGA The Model 50 s Video Graphics Array hardware is compatible with all previous IBM display adapters (monochrome, CGA, EGA, and MCGA), and it adds several new display modes of its own, including: • 640 x 480 sraphics in 16 colors (the MCGA provides only two colors at that res- olution); • 720 x 400 alphanumeric in 16 colors or monochrome; • 360 x 400 alphanumeric in 16 colors. Of course, the VGA can also run in the 256-color mode of the MCGA. By way of comparison, the EGA provides 640 x 350 in 16 colors in graphics mode. Apparently the VGA is not compatible with the Her- cules monochrome standard. It's worth pointing out that all supported modes will run on any PS/2 monitor That differs from most present multi-mode vid- eo adapters, which can run in various modes, but only on appropriate monitors (TTL monochrome, color, or enhanced color). There's much more to say about the VGA, but, unfortunately no space to do so at this time. CD C CD 00 ~4 65 FIG, 6 O O o O Q < Model 50 hardware notes As with the Model 30, surface-mount !C's are used extensively; plug-in cards extend appropriate signals from the motherboard to the floppy- and hard-disk drives. One very interestins feature of the Model 50 is the modular way in which all the sub-sec- tions snap together For example, as shown in Fig. 5, the floppy-disk drive snaps into place, and the edge connector provides mechanical as well as electrical contact (A plastic guide system beneath the unit locks it into place.) The hard-disk drive mounts in a similar manner, as do the bus -extender cards, and even the fan. The Model 50 includes three Micro Chan- nel bus slots (shown in Fig. 6); its sibling, the Model 60 (which we didn't evaluate), provides eight slots and a faster hard disk. Monitor mania There are several monitors available for all the new models; two are color displays (8512, 8513) and one is monochrome (8503). They all have the same resolution (720 x 400 in text mode, 640 x 480 in graphics mode); they differ mainly in price and size. Our cover shot was made with the 8512 monitor, a 14-inch model. The new monitors are analog types, which means that they are incompatible with the previous standards, although NEC has announced that their MultiSync monitor is compatible with the addition of a cable adapter. The new monitors are plug -com- patible with each other; the BIOS senses whether a color or a monochrome display is connected and routes signals according- ly If a monochrome monitor is attached and a color mode is active, the RGB signals are summed and output to the monitor via the DAC (Digital-to-Analog Converter) that controls green. It's unclear at present whether two monitors can function simultaneously; some CAD programs and debuggers use one screen for menus and control functions, and the other for program output. New BIOS and DOS The following discussion refers to the Model 30s BIOS and DOS 3.30. A new BIOS interrupt lOh function call (12h) provides a means of switching various vid- eo adapters on and off. Again, it's unclear whether external Hercules, EGA, or other adapters are supported. Another new BIOS interrupt function (In- terrupt 15h, function 4Fh) allows you to in- tercept keyboard scan codes as they are generated (via interrupt 9). The new func- tion allows you to change the scan code, or cause it to be ignored altogether That func- tion will aid remapping keys for foreign- language and technical word processing, but without resorting to illegal interrupt stealing as some word-processing and key- board-enhancing programs do. Another keyboard function (Interrupt 16h, function 5) allows you to stuff the keyboard buffer with key codes as if those keys had been typed. A number of other BIOS functions are not clearly documented, but seem to point in the direction of adding multi -tasking ca- pabilities to the machine, DOS 3,30 is not a major upgrade, but it is not insignificant either It contains greatly expanded support for foreign-language character display, extended network sup- port, and extended batch -file support, in- cluding a CALL command that allows one batch file to call another. (CALLing was pos- sible but awkward in previous versions of DOS.) The new DOS also supports all disk formats, ranging from the single-sided sin- gle density (160K) SV< format of the original PC to the 1.44 MB format of the models 50, 60, and 80. DOS 3.30 runs on all past and present models of the FC Conclusions All in all, the PS/2 machines represent real technological improvement in the PC family They are not a radical departure from past systems, nor are they misplaced machines like the PC Jr and the PC Portable. Rather, they represent an incremental step in the evolution of the PC family They're not the cheapest machines, but they set standards that others will follow. We applaud IBM's leadership efforts, and hope that it will con- tinue in the course it has set itself. Credits Media Cybernetics (8484 Georgia Ave., Suite 200, Silver Spring, MD 20910, 800-446-HALO) graciously sent us a beta- test copy of version 2.15 of Dr Halo, which supports the new video hardware; we used it to create our cover image. And thanks to AutoDesk, Inc. (2320 Marinship Way Sausalito, CA 94965), for sending a test copy of AutoCAD version 2.6. Thanks to Andre Duzant for cover art, and to Herb Friedman for cover photography|Q>4 MEMORY MINDER, DISK-DRIVE ANALYZER FROM J&M SYSTEMS Mechanical devices are always the first to go. In particular, disk drives are a primary source of trouble. To help you spot a potential problem before it develops into a catastrophe, you can take your drives to a repair shop for testing. Or you can buy a disk-drivs, analysis program for about the cost of two trips to the repair shop and run the diagnostics yourself. One such program is called Memory Minder It's sold by J & M Systems, Ltd. (15100A Centra! SE, Albuquerque, NM 87123, 505-292-4182), and it lists for $114. The package consists of three parts: a man- ual, a disk containing the control program, and a special test disk. The program disk uses the test disk to check drive speed, head and clamping alignment, and several other factors. How to run it First you boot your machine directly from the Memory Minder program disk. It then displays a menu that lets you select param- eters and run tests. After booting, the pro- gram disk is no longer needed; at that point, you insert the Digital Diagnostic Disk(DDD), manufactured by Dysan, into the desired drive. Disks are available for testing several types of drives. From the main menu you first run a clamp test (shown in Fig. 2), which tests the ac- curacy with which a diskette is clamped. If your drive can't pass the clamping test, chances are it can't pass any other tests either (It's also possible that the DDD has gone bad, in which case it must be re- placed for the healthy sum of $40.) Then you run a quick test, whose screen appears as shown in Fig. 7). Ifyourdrive fails any aspect of the quick test, you can run more-detailed tests. For example, spindle speed may be measured directly in RPM, and, if speed varies from the standard (300 RPM for a 5y4-inch drive) by more than ± 2%, the program tells you so. Another test checks the drive's head alignment. J&M provides generic instruc- tions for aligning a head, and wisely refers you to the manufacturer's alignment instruc- tions. Other tests check other aspects of the drive's operation, and a special set of rou- continued on page 72 66 K RCTROFIT Retrofit your PC or XT with a 3 1 /2-inch disk drive. HERB FRIEDMAN if you use an IBM PC or clone, you maybe underwhelmed by all the fuss being made about S'/s-inch disks. However; many porta- ble computers, and all of IBM's new line of PC's, use 3^-inch disks. (See "Editor's Workbench" for reviews of two of the new PC's.) The small diskettes have many advantages over the SVi-inch disk you're used to using, include • Increased capacity (two to four times that of a standard 360K floppy disk) • Greater reliability because each disk is completely enclosed by a hard plastic shell • Smaller, shirt-pocket size SVWnch disks are by no means obsolete, but chances are that the industry will move steadily toward use of 3'/?-inch disks, just as 8- inch disks were gradually supplanted by 5 'A -inch disks. So in this article we'll showyou how to retrofit your computer to use 3 1 /s-inch disks. Then you'll be ready to handle the upcoming new wave of software and data. We'll discuss installation of IBM's model 2683190 disk-drive retrofit kit for PC and XT model computers. Similar kits are available from clone manufacturers, but installation may differ, so your drive's instructions carefully What it is The retrofit kit consists of a cabinet- mounted 3 s k- inch disk drive with attached signal and power cables, a y-adapter that lets you tap S*w FIG. 1— THE CABLE FROM THE ZVvmtih drive has its own power connection take-off that matches the miniature power socket on the supplied Y-adapter. The ring through which the adapter's power wire loops is a toroid choke that help suppress RFl. power from your computer's internal disk-drive power connector (shown in Fig. 1), and a kit of three pre-punched metal brackets > c o c en 67 (shown in Fg. 2) that accept the Y-adapter's connector: installation is simple. First you mount the appropriate bracket on the rear apron of your computer Then you install the V-adapter in series with one of the existing internal disk-drive power con- nectors. Next, you push the small power connector through the hole in the bracket. That connector locks in position by means of mounting ears molded on the connector Finally you connect the cable from the3'/9-inch disk drive to the controller card in your main computer. With some PC's you won't need to install the power cable in series with the floppy power connector The reason is that the power supplies in some PC's have four power connectors. So, if you haven't used used all four, just connect the V-adapter to one of the unused connectors. Use the bracket that causes the least inconvenience. For exam- ple, if you use the relatively large standard rear-slot bracket shown in Fig. 2, you must give up an entire slot. Some PC's have only five slots, so it may prove impossible for you to use the large bracket. In that case you could use the smallest bracket, which will mount in the small hole abwe the cassette port (yes, the original PC included a cassette interface). The medium-size bracket can be used in the extra slot above the keyboard port on an XT. Clone panel layouts may vary so you" might have to use the full- size bracket and give up a slot. Or you might just cut a hole of your own in which to mount the small bracket. Standard controller To use the adapter, you must have an an IBM-type floppy-disk controller, the. kind with a 37-pin D-connector on the mounting bracket (as shown in Fig. 3), in addition to the resular floppy-disk •a FIG. 4— THIS IS A TYPICAL CLONE INSTALLATION. The disk- controller socket and the 3'/2-inch drive's power socket are on adjacent brackets. FIG. 5— CONNECTORS IN PLACE AND BEADY FOR USE. The 37- pin D-connector is a real heavyweight, so be certain that you tighten its mounting screws to ensure reliable operation. z o or & UJ _l UJ 6 Q < FIG. 2— THE RETROFIT KIT is supplied with three different brackets for the power sockets. Use the one that's most conve- nient for you, but remember that the standard bracket (the large one) may force you to give up use of one expansion slot. FIG. 3— IBM-TYPE DISK CONTROLLER cards have a 37-pin sock- et on the rear for external disk drives (C: and D:). The retrofit cable must connect to that socket. connector. The IBM control I er accommodates four floppy- disk driv- es: two internal and two external drives. Because the retrofit kit connects to the computer via the external 37 -pin connector, you cannot use a mu It i -function disk controller (the kind that combines a disk controller, serial and parallel ports, a joy-stick interface, and a clock), because it has no connector for external floppy-disk drives. The controller itself needn't be an actual IBM device; having the external connector is the important point. Figure 4 shows an XT clone ready to connect the 3'/s-inch disk drive. The external disk-drive connector is adjacent to the miniature power connector installed in the slot furthest left. To install the 3V?-inch drive, simply plug the appropriate con- nectors from the drive in the appropriate jacks, as shown in Fig. 5. Device driver Before you can use your new drive you must tell the computer that it's there by adding a device driver to your computer's CON- FIG.SYS file, the configuration file that's automatically read when the computer boots. For example, adding the line: DEVICE = DRIVER.SYS /D:2 to your CONFIG.SYS file will allowyou to access a 3Vs inchdisk drive as the next available drive (D: on an XT). IBM's device driver comes only with DOS versions 3.20 and 3.30, (Some clone manufacturer's drives are available with drivers that work under DOS 2.11. — Editor) The device driver informs your computer that the 3'/&-inch drive exists, establishes its physical parameters, including number of tracks, sectors per track, number of heads, etc., and sets the drive's logical designation (D:, E:, F:, etc.) 68 DESIGNING PC BOARDS ON YOUR COMPUTCR ROBERT GROSSBLATT Last ti m e, i n the J une i ssue, we exam i ned CAD ( Com p u te r Aid ed Design) in a general way seeing what kinds of things you can do (or should be able to do) with any worthwhile CAD package. This month we'll look at several specific packages, focusing on those that are of special interest to the electronics enthusiast. There are a number of packages on the market, and both price and performance vary considerably However, none of the pack- ages we reviewed are inexpensive. As we've seen, a layout pro- gram must contain several different but integrated parts, so a complete package represents a substantial investment in develop- ment time. In addition, the potential market is small, certainly much smaller than the markets for word-processing and database pro- grams. So development costs and market size translate into rela- tively high prices. smARTWORK The Wintek Corporation markets a package called smARTWORK, which probably is the most popular of the "inexpensive" routing packages. It has a graphics editor, router, and is capable of produc- ing high-quality output. The program is an "interactive" router — what we call a point-to-point router. After you place the compo- nents, you can draw traces yourself or tell the router which points you want connected together. smARTWORK wi 1 1 do its best to lay in the traces. The Wintek program only does the PC-board layout; there's no way to draw the schematic, generate a netlist, and have the router read the file. So using smARTWORK is in some ways similar to doing a layout by hand on graph paper smARTWORK is simple to use. After loading the program and creating a file, you begin your layout by placing the doughnuts and pads. The coordinates of the cursor are always shown on the bottom of the screen; that makes it simple to put a component in a precise location in the workspace. There area variety of pad shapes available, as well as commands to create various patterns for ICs (SIP and DIP layouts, for example) headers, and soon, automatically The finished layout is really the parts-placement diagram for the board you 're designing, so it's a good idea to work out a rough idea of where things are to be placed before you start smARTWORK Doing so will make it easier to avoid going beyond the edge of the board as well as to take into account any of the special placement considerations we've already mentioned. It's easy to make adjust- ments to the board when you begin routing the traces because smARTWORKs graphics editor has a set of commands to let you move, stretch, delete, and fill. > c o c CD to CO -si When you start routing traces, smARTWORK will let you do either a single- or a double-sided board, with an optional silk-screen layer. However, keep in mind the fact that the program can only handle two routing layers. If you want to do multilayer boards, you'll have to use another package. Each layer can contain two trace widths, thin and fat, and although you can choose between three preset thin widths, you can only use one on each layer The fat width, 50 mils, is the only one available, but you can produce a fatter trace by laying two or more traces near each other Routing can be done either by hand or by using the routing algorithm built into the progtam. However you do it, chances are that you'll want to rearrange traces as the layout develops — and that's where you'll appreciate the power of the graphics editor. It's easy to change anything on the board — it's really as simple as moving text around in a word processor. When tne design is complete, you can get hardcopy from a dot- matrix printer in either actual board size or double size. There are commands to control the intensity rotation, and size of the printed output As shown in Fig. 1, a much higher-quality printout can be obtained by using a plotter; smARTWORK supports several Which- ever device you use, smARTWORK will generate camera-ready art for photochemical board fabrication, Wintek can supply you with information about hardware compatibility Wintek markets another program called HiWIRE, a graphic sche- matic-drawing editor, and they're currently working on software that will let the two programs share common data files. Contact them directly at the address shown in the sidebar for more detailed information. Another company (Creative Electronics) is marketing a program FIG. 2— SMARTWORK also produces quality copy on a dot-matrix printer. (smARTCAD) that converts smARTWORK files into AutoCAD format. (We discuss AutoCAD below) When you do convert a file, each side of your PC board will be on a separate layer, and you can use any AutoCAD editing command to do tilings you just can't do with smARTWORK. For example, you can: • Add text in any size and font. • Place pads for odd-sized components. • increase board size beyond 10 x 16 inches. • Use a different grid spacing. • Prepare a solder mask. o z Q rr k- o ill Q DC FIG. 1 — SMARTWORK produces high-quality camera-ready work when- used with a good plotter. Project :PCB A new low-priced entry is called Project :PCB; it's made by DASOFT Designs, Inc., and it has many features that are missing from smARTWORK, including a means for schematic capture and a true auto-router; The circuit diagram can be entered with a graphics editor; the program can extract the net list directly from the drawing. You can also enter and edit connections in text form directly from the keyboard. The software comes with a limited component library but you can use a parts editor to build new parts that can then be called up automatically when you're entering a schematic. In fact, ProjectiPCB actively encourages you to create symbols and share them with others,- the company has set up a bulletin board (415-486-0862) where users can share custom parts and libraries, and where the company will post information on updates, bug fixes, new versions, etc. To use Project: PCB, first you create the schematic. When it's finished, you use the layout editor in a graphics mode to define the overall shape of the board and to place the components. Then you're ready to route the board. It can be done automatical iy with Project:PCB by selecting the Route option on the menu, or you can enter traces manually before turning the router loose on the layout. One of the nicest features of the program is the ability to tell the router to do only a single net and then stop. That means that you can pre-route power and ground lines, for example, before going on to the rest of the board. The router goes over the board twice But you can set it up to do only one side of the board and then stop. That gives you the opportunity to try to improve the layout by hand, and then have the router go through that side again. Doing the layout that way can be valuable, because feedthroughs are the inescapable con- sequences of double-sided boards, and plated-through holes are difficult to do at home and expensive to do commercially Project:PCB can deliver hardcopy to a variety of plotters, but printer output is limited to text dumps of the various data files that are generated by the program. If you have one of the plotters supported by the program you'll get beautiful camera-ready art- work that's perfect for board production. The program has more stringent hardware requirements than smARTWORK. Much of the equipment (mouse and plotter, for example) that is optional with smARTWORK is required to run 70 ProjectiPCB. But ProjectiPCB has a much more extensive graphics package, as well as an auto-router Autoboard At the other end of the price/performance spectrum is a program called Autoboard. It is designed for serious production. It has every feature we've already discussed, and many many more. In fact, comparing it to the packages we've been discussing is like compar- ing a Ford to a Ferrari — they're in different leagues altogether Of course, the added capabilities don't come for nothing. In order to concentrate all their energy on the routing package, the Great Softwestern Company decided to look elsewhere for the graphics editor That was a wise decision. Autoboard, in addition to its auto-router, is a collection of over- lays, script files, menus, macros, and drawings to turn AutoCAD into an electronics graphics package. It goes without saying that Auto- CAD is one of the most powerful and most supported graphics editors on the market. So one of the great strengths of Autoboard is that it makes full use of AutoCAD. The schematic and board layout are entered in AutoCAD; Autoboard s custom menu system makes it simple to do so. While building the schematic or the board, you can use any of AutoCAD's awesome range of commands to edit the drawing you're working on. The parts library from Autoboard is extensive, and you can create new parts by building their definitions in a word processor — a straightforward procedure that's described in the manual. Autoboard is designed for commercial board fabrication, so it has some impressive capabilities: t. It can route boards up to 16 layers thick. 2. It can handle more than 1000 components on a board. 3. More than 40 buses can be defined. 4. You can have as many IC arrays as you want. 5. More than 1000 pins can be tied together FIG. 3— AUTOBOARD routed this board automatically using a schematic created with AutoCAD. TABLE 1— PROGRAMS DISCUSSED smARTWORKS The Wintek Corporation 1801 South Street Lafayette, indiana 47904-2993 $895.00 Copy Protected Project: PCB DASOFT Designs Systems, Inc P.O. Box 8088 Berkeley, California 94707-8088 $950.00 Hardware Locked The Autoboard The Great Softwestern System Company, Inc. 207 W. Hickory St. Suite 309 Denton, Texas 76201 $2500.00 Requires AutoCAD AutoCAD Autodesk, Inc. 2320 Marinship Way Sausalito, California 94965 $2850.00 (Version 2.5 or above) smARTCAD Creative Electronics 925 Fairwin Ave. Nashville, Tennessee 37216 $395 6. Board dimensions can be up to two feet square The fourth item in that list deserves a little explanation. Some IC's (memory devices, for example) are put on a board as a block, and the traces that connect them are laid out in a standard fashion. Autoboard has built-in algorithms to generate those traces, and there are routines in the graphics editor to place the IC's on the board with proper spacing. The best way to indicate how Autoboard works is to describe the process of creating a board. Remember that you must own a copy of AutoCAD (and know how to use it!) in order to use Autoboard. The first Step, as with ProjectiPCB, is to tell Autoboard about the schematic you're using. There are a series of batch files that do all the setup work for you (open data files, call up AutoCAD, and load a series of custom menus and scripts). Parts are chosen from menus along the right side of the screen,- AutoCAD prompts you for orientation and location. As you move the cursor around the screen, the part you're working with drags along until you place it. Next you're asked for the part's number and value. Last, AutoCAD draws the part on the screen along with the other information. When the parts are all placed and identified, you connect them together using either AutoCAD's Line command or the Line macro in the Autoboard menus. There's a difference. Autoboard s Line com- mand will automatically place the line in the correct layer for the software that reads the drawing file and generates the list of con- nections. You can switch between layers using the normal AutoCAD commands, but it's simpler to use the macros. When the drawing is sized, titled, and completed, a special command converts the schematic information to a netlist for use by the rest of the program; it also makes sure you don't have any unconnected components or lines. If it finds any it lets you know by listing them on the screen as text — but that's not all. One of the layers that Autoboard defines when it sets up Auto- CAD is called the Warning layer. If there are any uncommitted pins, unterminated lines, etc., Autoboard will return you to AutoCAD, and the points in question will have small red circles around them. > c a c 71 R-E Computer Admart IC PROMPT DELIVERY!!! ■B SAME DAY SHIP PING ( USUALLY) 19 QUANTITY ONE PACES SBQWH iq, uxt 2*. 1MT ( -l 1 1 S IDE [ 1 K . 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CIRCLE 203 ON FREE INFORMATION CARD to o z O cc r- o UJ Q < rr EDITOR'S WORKBENCH continued from page 66 tines aid in performing a traditional align- ment by allowing you to position the head to any track. Each test is activated from its own screen from which you can select the drive to test, the head (0 or 1) to test, and the location on the DDD to test. You can print any screen by choosing the appropriate menu item. In ad- dition, a setup screen allows you to estab- lish specific operating characteristics, including disk type, serial-port parameters, main or alternate test tracks, etc, (The alter- nate tracks on the DDD are provided so that FIG. 7 you can continue to use the disk after the first set wears out.) Recommendations Memory Minder is rather expensive for hobbyist use. However, if you split the cost amons several persons, each of whom might use the program two or three times a year, Memory Minder is worthwhile. The manager of a small office with a number of PC's could easily justify the cost of the pro- gram, and if he uses it conscientiously it could prevent valuable data from being lost, and thereby make an employee very happy What to do with the information Memory Minder provides is another story If you have no experience alisning disk drives, it's probably best to leave well enough alone, unless you're willing to experiment and possibly pay the consequences. But as a diagnostic aid, Memory Minder is a well- thought-out, easy-to-use product.|<D| 72 MICRO FLOPPY DISK DRIVES continued from page 68 You can access the disk tike this: The 3'/9-inch drive is automat- ically assigned the next available drive letter (after all floppies and hard disks, if any). For example, if your hard disk is drive G, the 37s- inch drive becomes drive D:. If you have two hard drives, G and D:, the 372-inch drive becomes drive E:. If you have no hard disk, but you do have a RAM disk set up as drive G, the 37s-inch drive again becomes drive D:. Logical and physical You may wonder whether you can copy a file from one 37a-inch diskette to another without going through an intermediary device such as a hard disk, a RAM disk, or even a 5Y*-inch floppy disk. You can (using DOS 3.20 or DOS 3.30). What you do is enter the device driver program into the CONFIG.SYS file twice. For example: DEVICE DEVICE = DRIVER.SYS,'D:2 = DRIVER.SYS '0:2 The computer is then fooled into thinking that there are two physicdt 3Ya-inch drives with different logical designations (D: and E;, for example). DOS will prompt you to switch disks when that is appropriate. That's not as complicated as it may sound. It's really the same capability we've always had with the ISM, but extended to handle more drives and more types of drives. If you've ever copied a file from A: to 8: on a machine with only a single floppy-disk drive, you know how it works. For example, assume that you have a single floppy drive and a hard disk. The floppy functions as drives A: and B: and the hard disk functions as drive G. You can install two device drivers that tell the computer that the 37e-inch drive will function as both D: and E:. Now there's no problem copying files between separate 334-inch disks via a single drive. The computer will prompt you when to swap disks. You might prefer to do it this way: Use the motherboard's DIP switch to program four floppies, even if you have only two. The hard disk automatically becomes drive E:. Configure the device driver so the 372-inch drive is G. That will leave D; free for use as a RAM disk. Then the entire disk lineup will be A: and B: as 574-inch floppies, Gas a 37s-inch floppy D: as a RAM disk, E: as the hard disk, and F: as the second logical designation for the 37a- inch floppy Setting up the device driver can become somewhat compli- cated, but bear in mind that, when it's over, to interchange data between any combination of disk drives, you can use the normal DOS COPY command. One final point: There are a number of different 3Vs-inch disk formats. For example, the Tandy Model 100 disk drive has one format, the Macintosh computers have another, and IBM now has two of its own, both high-density (1 .44 megabyte) and low-density (720K). The high-density format is used only in the new Models 50, 60, and 80; the low-density format is used in the new Model 30, IBM's laptop, as well as laptops from a number of manufacturers (including Zenith, Toshiba, etc ) The upgrade described here can read only the low-density IBM forma t.|(D4 COMPUTER DESIGNED PC BOARDS continued from page 77 To correct a mistake, you can connect an uncommitted point using the Dot command, which draws a small blue circle there and informs Autoboard that you want a connection. If the pin was left open by design you can just isnore the warning. The next step is to define the board and place the parts. Once again, Autoboard has a set of files that customize AutoCAD with menus and macros. After the board outline is defined, you can begin laying the parts out in much the same fashion you did when the schematic was drawn. Pic kins a P art f rom a menu allows you to drag it around the screen and place it exactly where you want it. It's a tremendous help to use AutoCAD's Zoom command to zero in on a location if you're placing a small part. The drawing of the part you drag around the screen will be enlarged by the same amount, so you'll be able to judge relative placement and size. Once you've picked the insertion point, you'll be asked for the name of the part and its value. They must be consistent with those you used in the schematic entry phase, because Autoboard's router . uses those names to identify the parts and also the connections in the netlists. When you complete the layout, you can hand-route some traces if your circuit has requirements you're afraid won't be properly addressed by the router Next you'll want to turn the auto- router loose; that's done simply by giving it the name of the board you want routed, Autoboard is an open system in that all the menus and script files (and many other parts of the program) can be customized to fit your requirements. The same is true, to a lesser extent, of the router There are a series of "switches" you can set in the router that control things like the number of allowable layers, minimum and maximum pad and trace widths, spacing, time limits, and soon. That is easily done by editing a configuration file with a word processor The router automatically looks for that file when it starts to run. If it can't find it, it uses its default values. There's something magical about watching the router in opera- tion because it constantly reports its progress on the screen. Our example board was one that had already been done by hand (we showed it last time), and it was amazing, to say the least, to watch Autoboard do in 15 minutes what had taken two days to do by hand. The only consolation was that all connections were made in the hand- routed board, but Autoboard missed five (out of a total of 115). That's not a bad percentage, and it's a safe bet that tweaking the configuration file could result in a success rate of 100%. The last thing the router does is call up AutoCAD, draw the board on the screen, and display all the traces it has finished. It creates a separate "rats-nest" layer for the missed routes and draws them on that layer in a different color It also creates a text file with a BAD extension that lists all the connections it missed. By the time reach this point, you're in AutoCAD looking at the routed board with each board layer in a separate AutoCAD layer (including separate ones for the pads and the silkscreen). Now is when you'll appreciate the fact that Autoboard works inside AutoCAD. You can use any Auto- CAD command to do anything you want to any layer — you have complete control of the drawing. When you're happy with the layout, you can use any of Auto- CAD's normal output commands. So you can create a text file that describes the board (for conversion to FutureNet, Gerber, etc.), or you can print it, plot it, etc. AutoCAD knows how to talk to virtually every printer and plotter ever made, so you can be confident it wi 1 1 talk to yours. And AutoCAD files are one of the few standards for graphic data. As for input devices, some sort of digitizing tablet is tremendously helpful in drawing both schematics and layouts. And, as with printers and plotters, AutoCAD knows how to talk to just about all of them. The keyboard, of course, can be used alone or in conjunction with a digitizing tablet. Conclusions Each of the packages we've been talking about is a well-thought- out piece of software, and each is updated occasionally All the n graphics produced for this article were done on an IBM PC XT with a g? Sigma Designs Color400 Video Board, an SR-12 monitor from i- Princeton Graphics, and a Summamouse from Summagraphics, 3 And a very special bit of thanks must go to Dennis Jump for ® standing by the phone.^CD^ < 73 to o o <r o LLI g D < 74 SATELLITE TV continued from page 29 end up selling the TV viewers a better picture in order to attain an international standard. Why an international fuss about the technical nitty-gritty that goes into a TV picture? Because there is a crying need for a universal televi- sion standard. High-tech com- munication systems, such as satellites, can now beam a TV pic- ture from any part of the world to any TV set, so there must be a con- venient way for everyone to view programming from any spot on the globe. Since there are three wide- ly-used television standards now in use — NTSC, the North Amer- ican or US standard; PAL, the basic all-Europe standard; and SECAM, the joint French-Russian stan- dard — the exchange of television programming such as the Olym- pics, and news feeds, and even family programming, has been a burden because the equipment that converts one TV standard to another is expensive and prone to failure. While it is possible to manufac- ture a receiver capable of receiving the three types of TV signals, they are, and are likely to remain, pro- hibitively expensive. Multi-stan- dard receivers, such as those that are available in small quantities in Europe and the Middle-East, are not cost-effective because a major portion of the circuitry must be duplicated, even triplicated, to ac- commodate the different trans- mission standards. Whose HDTV? Television formats, as we know them today, originated in the 30's and 40's. (NTSC color was appen- dixed to an existing black-and- white standard in the 50's.) Even if we could conveniently and inex- pensively interchange the signal formats, all of the systems, NTSC, PAL, and SECAM, realize approx- imately half of the picture defini- tion that's possible using 1980's technology. Although present technology makes a 1,000- to 1,200-line video transmission system do-able at consumer prices — European, Jap- anese, and North American firms all have such systems operating — like the NTSC/PAL/SECAM de- velopments, no two of the pres- ently developed systems share the same standards, so we're back with the same old problem. Many engineers believe that there is general worldwide ac- knowledgment that we must avoid entering the era of HDTV with three different "national stan- dards," and that since the present- day transmission standards are ready to be replaced, a serious effort should be made to adopt new standards it will resolve the 50-year old problems related to multiple, non-compatible sys- tems. Unfortunately, it will require uncommon resolve to push the strong nationalistic instincts into the background in favor of a sin- gle, worldwide-technology stan- dard. If it happens, it will be the first time that the world has agreed on an important broadcasting standard. R-E Radio Electronics REPRINT BOOKSTORE Q SP1 Special Projects #1 S6.00 □ SP4 Special Projects #4 (Summer 1982) . . $6.00 □ SP5 Special Projects #5 (Winter 1983) . . . S6.00 D SP6 Special Projects #6 (Spring 1983) , . . S5.00 □ SPT Special Projects #7 (Summer 1983) . . $6.00 H SP8 Special Projects #8 (Fall 1983) 16.00 C SP9 Special Projects #9 (Winter 1984) . . .$6.00 D SP1D Special Projects #10 (Spring 1984) . .$6.00 H 111 Hands-On Electronics #1 $5.00 H 112 Hands-On Electronics #2 $5.00 □ 113 Hands-On Electronics #3 $5.00 O 11* Hands-On Electronics #4 $5.00 3 115 Hands-On Electronics #5 $5.00 U 115A Hands-On Electronics #6 $4.00 □ 116A Hands-On Electronics (Jan-Feb '86) . . S4.00 □ 116B Hands-On Electronics (Mar/Apr 86) $4.00 □ 116C Hands-On Electronics (May/Jun '86) S4.00 □ 116D Hands-On Electronics (Jul/Aug '86) . . S4.00 □ 116E Hands-On Electronics (Sep/Oct '86) ..$4.00 □ 116K Hands-On Electronics (Nov '86) S4.00 □ 116L Hands-On Electronics (Dec '86) S4.00 □ 117 Hands-On Electronics back issues (1987)$3. 50 Write in issues ctesined. LI 150 TV Descrambler $3.00 HI 151 Build Your Own Robot $12.00 □ 152 8-Ball Satellite TV Antenna $5.00 D 107 Radio-Electronics back issues (1987) $3.25 □ tflfi Radio -Electronics back issues (1986) . . $3.75 Write in issues desired □ 105 Radio-Electronics back issues (1985) . . $4.25 (Jan. 85 not available) Write in issues desired To order any of the items indicated above, check off the ones you want. Complete the order form below, include your payment, check or money order (00 NOT SEND CASH), and mail to Radio-Electronics, Reprint Depart- ment. P.O. Box 1079, Farmingdale, NY 11735. Please allow 4-6 weeks for delivery. □ 104 Radio-Electronics back issues (1984) . . $5.25 (December 1984 issue is not available) Write in issues desired. D 103 Radio-Electronics back issues (1983),,.. $5, 75 (Jan. , Feb. , May are not available) Write in issues desired. □ 102 Radio-Electronics back issues (1982) $6.50 (Jan., Feb.) is not available) Write in issues desired G 101 Radio-Electronics back issues (1981) . . $7.00 (Issues available: July, Aug. Sept. Nov) Write in issues desired □ 153 Etch your own PC boards $3.00 D 154 How to Repair VCR's $3.50 P 155 IBM Typewriter to Computer S3. 00 Q 125 Radio-Electronics Annual 1985 S3. 50 Q 126 Radio-Electronics Annual 1986 $2.50 □ 156 How to Make PC Boards $2.00 □ 157 All About Kits S2.00 □ 158 Electro Importing Co. Catalog (1918) . . $5.95 □ 159 Low Frequency Receiving Techniques Building and using VLF Antennas $6.00 D 160 New Ideas - 42 Circuits $3.50 □ 161 Descrambling(Feb., 1984) $2.00 □ 162 Build Your Own Satellite TV Receiver $7.00 U 163 Receiving Satellite TV $7.00 □ 164 Modern Electrics (April, 1908) $3.00 □ 165 How to Repair CD Disc Players $5.00 □ 166 Collected Works of Mohammed Ullyses Fips (62 pages, April Fools Collection) .... $10.00 □ 167 Designing With IC's $4.00 If you need a copy of an article that is in an issue we indicate is unavailable you can order it directly from us We charge 50C per page. Indicate the issue (month & year), pages and article desired. Include payment in full, plus shipping and handling charge. Make checks payable to Gernsback Publications. Inc. ARTICLE PAGES MONTH YEAR TOTAL PAGES r&SOC each TOTAL PRICE MAIL TD: Radio-Electronics Reprint Bookstore, P.O. Box 4079. Farmingdale NY 11735 SHIPPING CHARGES IN USA & CANADA $0.01 to S5.00 $1 .00 $30 01 to 40.00 ... $4.75 $5.01 to $10.00 $1 .75 $40.01 to 50.00 .... $5 75 $10.01 to 20. 00 $2.75 $50.01 and above. .. $7.00 $20.01 to 30,00 $3.75 Total price of merchandise $ Sales Tax (New York State Residents only) , $ Shipping (see chart) . , E All payments must be In U.S. funds OUTSIDE USA S CANADA Multiply Shipping by 2 lor sea mail Multiply Shipping by 4 for air mail Name Address . City Total Enclosed -State . -Zip- R-B-87 PC Service jqJlLtifiir^ ifc -« 5 INCHES *- USE THIS BOARD to assemble the digital tachometer's display board. The article appeared in the June 1987 issue. + + + -4-1/16 INCHES- THE MAIN BOARD for the digital timer is shown here. You can find the story beginning on page 45. > C Q THE DISPLAY BOARD for the digital timer is g> Shown here, ■>! 75 PC Service i w o z o CE I- o UJ < cc 76 AMP DESIGN continued from page 56 BASE BIAS VOLTAGE < DIVIDER FIG. 1— A COMMON-EMITTER AMPLIFIER was the ideal solution to our design problem. FIG. 2— SIMPLE CALCULATIONS yielded the component values shown here. through R I is a combination of the volt- age-divider current plus the base current. The base current is equal to the collec- tor current divided by beta. It is found from: l B - 1.28/100 = 0.0128 mA So the total current through R I is 0.054 mA + 0.0128 mA = 0.067 raA, and R] = i 0.8/0. 067 m A = 160,000 ohms. Resistor Rl is the most critical resistor in the circuit. To ensure maximum voltage swing, it should bring the quiescent col- lector voltage to one half the supply volt- = 10.8/0.067 mA = 160,000 ohms. Resistor Rl is the most critical resistor in the circuit. To ensure maximum voltage swing, it should bring the quiescent col- lector voltage to one half the supply volt- age. After building the circuit, the value of Rl may have to be varied slightly to achieve that voltage swing. We now have a circuit we can test. Interfacing Connecting the circuit to the outside world will require capacitor coupling. That serves to isolate the AC signal front any DC bias voltages. Figure 3 shows our complete circuit with input and output coupling capacitors. The values of those capacitors were calculated using C = 1/(3.2 X / x R), where C equals the capacitor value in farads, /equals the fre- quency at which response will be down I dB, and R equals the impedance on the load side of the capacitor. To calculate the value of CI , the ampli- fier's input impedance (I5K) is used for R. To calculate the value of C2, the input impedance of the next stage (50K) is used for R. The value of CI can now be calculated foradropofldBat20Hz:Cl = 1/(3.2 X 20 X 15000) = .00000104 farad =1.0 p.F. The value of C2 = 1/(3.2 x 20 x 50000) = .00000031 farad = 0.33 p.F. To increase the gain of the stage, you could bypass R b with a capacitor, as shown in Fig. 4. Nothing comes for free, however. The price you pay for increased gain is lower input impedance, which will vary widely with beta. If that variation is not a problem, a significant gain increase can be realized by adding the bypass ca- pacitor. Our original circuit has a gain of 10; if the emitter is bypassed the gain becomes R c /0.03/I li = 4700/(0.03 / 0.00129) = 4700/23 « 200. The value of the bypass capacitor in farads is calculated from the formula C = 1/(6.2 X / X R). Again / is the low- frequency limit in Hz, and R is the dy- namic emitter resistance (0.03/I R ), In our example, if we stick to a 20-Hz lower limit we have C = l/[6.2 x 20 X (0.03/ 0.00129)1 = .000344 farads = 344 p.F. A 350- p.F unit can be used. Computerized calculations It only seems natural to put the comput- er to work to lessen the drudgery of doing repetitive mathematical calculations. The BASIC program shown in Listing 1 is written to do just that. In addition, it serves as a sort of scratch pad for your designs, and allows you to do several "what-if" calculations easily. The pro- gram was written for a Commodore 64, FIG. 3— CAPACITOR COUPLING is required to interface the amplifier to the outside world. + 12V Rl jj 160K CI . I.DnF' INPUT I Re 470011 ^CT R2 22K EMITTER "BVPAjS C3 v 350u-F T C2 -33nF OUTPUT 470!! FIG. 4— INCREASE GAIN by bypassing the emit- ter resistor as shown here. but it can be modified to run on any other system. A few thoughts on components before we finish: Using 5% resistors allows closer adherence to the calculated values. Because of their temperature stability and low leakage specifications, silicon rather than germanium transistors are preferable for this type of circuit. Finally, you've no doubt noticed that we have yet to specify a specific transistor. That's because for this type of application it really doesn't matter! Almost any small-signal device will do fine. B-E > c a c CO CD CD 77 CO o z O LU 6 □ < 78 COMMUNICATIONS CORNER continued from page 31 dB greater than the signal received by a single antenna. A special de- tector samples the signal-to-noise ratio of the received signal on a half-cycle basis. If out-of-phase multipath reception at one anten- na causes the signal-to-noise ratio to fall below a minimum value, the detector automatically inserts the delay line by opening the elec- tronic switch, thereby flipping the phase of the signal from antenna b by 180°, which in turn causes the delayed signal to add once again to that of antenna a. To avoid constant switching back and forth, which might dis- tract the listener, the detector is designed so that it maintains the phasing as long as the received sig- nal is strong enough to be usable. Only if new or changing multipath signals degrade the "out of phase" signal to an unacceptable value will the detector cause the delay line to switch out. Some of you familiar with selec- tive fading on the high-frequency shortwave bands will wonder what happens to the receiver's volume level when the signal varies within the allowed range (before it falls low enough to activite the delay- line switching). The answer is that nothing happens; there is no change in volume level. On the shortwave frequencies, all signals are AM or single sideband (which, of course, is only a variation of AM), so tbe volume level from the speaker will vary if the signal level breaks away from control of the AGC (/Automatic Cain Control) or the AVC (Automatic Volume Control); that's a condition abso- lutely bound to occur during se- lective fading. But wireless sound equipment uses FM modulation, whose re- ceived volume level depends on deviation, not signal strength. Only if the signal falls to an almost- useless level is there any effect on an FM signal's volume level, and the receiver squelch circuits will mute the sound long before the listener hears a change in volume level caused by the received signal strength. R-E Electronics KnTOD PANASONIC CABLE CONVERTERS, Wholesale and Retail. Scientific Atlanta and Pioneer Cable Converters in stock. Pan- asonic model 130N 68 channel converter $79,95, Panasonic Amplified Video Control Switch Model VCS-1 $59.95. Scientific Atlan- ta Brand new Model #8528 550MHZ 80 Channels Converter $89.95. Video Corrector (MACRO, COPYGUARD, DIGITAL) EN- HANCER $89.95. Write or call BLUE STAR IND., 4712 AVE. N, Dept 105, Brooklyn, NY 11234. Phone 1-718-258-9495. CIRCLE 85 ON FREE INFORMATION CARD SIMPLY SNAP THE WAT-50 MINIATURE FM TRANSMITTER on top of a 9v battery and hear every sound in an entire house up to 1 mile away! Adjustable from 70-130 MHZ. Use with any FM radio. Complete kit $29.95 + $1.50 S + H. Free shipping on 2 or more! COD add $4. Call or send VISA, MC, MO. DECO INDUSTRIES, Box 607, Bedford Hills, NY 10507. (914) 232-3878. CIRCLE 127 ON FREE INFORMATION CARD BUILD STEVE ClARCIA'S INTELLIGENT SERIAL EPROM PROGRAMMER. • Use Standalone or with Computer/Terminal; • Programs Standard or Fast Algorithm Mode; • Menu Selectable, No Configuration Jumpers; • Programs All 5V 27XXX EPROMs from 2716 to 27512. Includes CMOS and 12.5V Vpp; • Read, Copy, Verify after Write; • Intel Hex File Upload/Down- load. Full Programmer Kit $199.00, Power Supply add $19.00. S&H $5 in USA. CCI, 4 Park St., Suite 12, Vernon, CT 06066. (203) 875-2751. CIRCLE 196 ON FREE INFORMATION CARD CALL NOW AND RESERVE YOUR SPACE 6 x rate $745.00 per each insertion. Reaches 242,400 readers. Fast reader service cycle. Short lead time for the placement of ads. We typeset and layout the ad at no additional charge. Call 516-293-3000 to reserve space. Ask for Arline Fishman. Limited number of pages available. Mail materials to: mini-ADS, RADIO-ELECTRONICS, 500- B Bi-County Blvd., Farmingdale, NY 11735. 2645T— 117 PRACTICAL IC PROJECTS YOU CAN BUILD $10.95. Dozens of fully- tested, ready-to-build circuits you can put to- gether from readily-available, low cost IC's! There are a total of 117 IC circuits ranging from an audio mixer and a signal splitter to a tape-deck amplifier and a top-octave gener- ator organ! From TAB Books. To order your copy send $10.95 plus $2.75 shipping to Electronic Technology Today Inc., P.O. Box 240, Massapequa Park, NY 11762- 0240 Electronics MSMl SIGNAL ELIMINATOR ■ TUNABLE NOTCH FILTER— for elimination of any TV, FM, or VHF signal. Can be tuned precisely to ANY signal within these ranges: 'MODEL 26-Ch's. 2-6 plus FM [54-108 Mhz] •MODEL 1422-Ch's. 14{A)-22(I) [120-174 Mhz] 'MODEL 713-Chs. 7-13 [174-216 Mhz] Highly selective 60dB notch. Send $30 each. Quantity prices as low as $15. Money back guarantee. STAR CIRCUITS, P.O. Box 8332, Pembroke Pines, FL. 33084 CIRCLE 94 ON FREE INFORMATION CARD THE MODEL WTT-20 IS ONLY THE SIZE OF A DIME, yet transmits both sides of a tele- phone conversation to any FM radio with crystal clarity. Telephone line powered - never needs a battery! Up to 'A mile range. Adjusta- ble from 70-130 MHZ. Complete kit $29.95 + $1.50 S + H. Free Shipping on 2 or more! COD add $4. Call or send VISA, MC, MO, DECO INDUSTRIES, Box 607, Bedford Hills, NY 10507. (914) 232-3878. CIRCLE 127 ON FREE INFORMATION CARD BUILD STEVE CIARCIA'S NEW VIDEO DIGITIZER. ♦ True "Frame Grabber", pic takes 1/60th sec • Not bus Dependent - Standalone digitizer • Serial output, trans- mits 300bps to 57.6Kbps • Resolution: 256 x 244 x 6 w/64 level grayscale • Accepts any NTSC video input, B&W or Color • Optional Rec/Display makes Video Tele- phone • Images can be stored & displayed on IBM PC. Full Digitizer/Serial Transmitter Kit - $249. Call for other options and specs, CCI.4 Park St., Suite 12, Vernon, CT 06066. (203) 875-2751. CIRCLE 198 ON FREE INFORMATION CARD NEW 442 SYNE WAVE DECODER WITH VARI SYNC— Replaces the oak N-12 $80.00, S.B. add on decoder $99.00, S.B. Tri-Bi de- coder $100.00, Zenith SSAVI $185.00, S.B.- S.A. decoder $140.00, Starcom converter $139.95. Buy a decoder take off $(10.00). Guaranteed. (402) 331-4957. Call or write for your free catalog. Many other products & quantity pricing. M.D. ELECTRONICS, 5078 So. 108th #11 5A, Omaha, NE 68137 CIRCLE 204 ON FREE INFORMATION CARD LOOKSOUND FM SUNGLASSES. Super durable sunglasses with that great look. Each one has a state of the art micro FM radio built right in. Great for jogging, bicycling, boating, sports events, etc. $39.95 plus $3.00 ship- ping and handling. Visa, mastercard, and cod. 1-800-522-2636 for orders. (617) 843-1900 for information. CAMEO ENTER- PRISES INC. P.O. Box 63 Accord, MA 02018 CIRCLE 89 ON FREE INFORMATION CARD A CAREER START FOR THE 21ST CEN- TURY. Since 1905, National Technical Schools has helped people build successful careers. Enter the 21st Century through home study courses in Robotics, Computer Technology and Servicing, Microprocessors. Video Technology, Basic Electronics, Trans- portation Technology, Climate Control Tech- nology or TV and Radio Servicing. For a FREE catalog, call 1-800-B-BETTER. Or write NTS/INDEPENDENT TRAINING GROUP, 456 West M. L. King Jr. Blvd. L.A., CA 90037. CIRCLE 187 ON FREE INFORMATION CARD 2706T— BUILDING METAL LOCATORS, A Tresure Hunter's Projects Book $9.95. Build your own high-quality metal detector for a fraction of the factory-built cost! The detec- tors described in this unique project guide will locate anything from coins and jewelry to gold and silver — and can be built quickly and easi- ly! From TAB Books. Get your copy today. Send $9.95 plus $1.75 shipping to Elec- tronic Technology Today Inc., P.O. Box 240, Massapequa Park, NY 11762-0240. ZENITH SSAVI $169; Level II $199. Recon- ditioned. Surplus Sylvania 4040 Converters- DIC, N-12, MLD 1200, new low quantity prices. Satellite systems, converters, ampli- fiers, accessories. SSAVI project handbook $6.50 ppd. Radar speed gun for baseball, car/boat racing, bowling, skiing, etc., from $275. Professional models used by police. Catalog and coupon $1.00. AIS SATELLITE INC., P.O. Box 1226-R, Dublin, PA 18917. (215) 249-9411. 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CIRCLE 191 ON FREE INFORMATION CARD > O c en 79 RE ROBOT continued from page 60 LISTING 2 : BOX ( feet -— ) RERB 25.5 IPS 2DUP (FEET) FORWARD 90 DEGREES RIGHT 2DUP (FEET) FORWARD 90 DEGREES RIGHT 2DUP (FEET) FORWARD 90 DEGREES RIGHT 2DUP (FEET) FORWARD 90 DEGREES RIGHT; LISTING 3 : MS ( milliseconds — ) ?DO 33 DO LOOP LOOP ; : SECONDS ( seconds — ) 0?D0 1000 MS LOOP; : MINUTES ( minutes — ) ?DO 60 SECONDS LOOP CO o z O cr i- o LU _l Lii g □ < EL LISTING 4 : ATTENTION ( — ■ ) BEEP BEEP 1 SECONDS ; : WARNING ( — ) 5 DO BEEP 1 SECONDS LOOP ; : TURN-AROUND ( — ) RERB 10 IPS 180 DEGREES LEFT; : TURN-LEFT ( — - ) 90 DEGREES LEFT ; : TURN-RIGHT ( — ) 90 DEGREES RIGHT ; r AHEAD ( feel — ) FEET FORWARD ; : COLLECT ( minutes — ) ATTENTION MINUTES WARNING : recharging area and turn around to go forward. The word TURN-AROUND makes a 1 80° turn. The word AHEAD is shorthand tor u forward move. COLLECT combines the ATTENTION. WAITING, and WARNING functions, because we al- ways use them together. The definitions of those words are shown in Listing 4. A frip consists of backing out of the techarger and exiting the mail room, mak- ing a clockwise trip around the office, slopping at several points (including a long stop at the president's office), and finally returning to the mail room. The FIG, 2— MODEL OFFICE FOR THE EXPERIMENTAL TRIP program that is shown in Listing 5. LISTING 5 ; TRIP ( -— ) WARNING RERB 20 IPS 3 FEET BACKWARD TURN-AROUND 2.5 AHEAD TURN-RIGHT 12 AHEAD TURN-LEFT 5 AHEAD TURN-LEFT 36 IPS 10 AHEAD TURN-RIGHT 2 COLLECT 7 AHEAD 2 COLLECT 8 AHEAD TURN-RIGHT 25 AHEAD TURN-RIGHT 3 AHEAD 2 COLLECT 11.5 AHEAD 4 COLLECT 11.5 AHEAD TURN-RIGHT ATTENTION 3 COLLECT ( President) 14 AHEAD TURN-LEFT 4.5 AHEAD TURN-RIGHT 12 AHEAD TURN-LEFT 10 IPS 5.5 AHEAD word TRIP executes the entire program; it is shown in Listing 5. TRIP only causes the robot to make one excursion around the office, but we want LISTING 6 MAILBOT ( — ) 8.5 AM WAIT-UNTIL TRIP 9.5 AM WAIT-UNTIL TRIP 10.5 AM WAIT-UNTIL TRIP 11.5 AM WAIT-UNTIL TRIP 1.5 PM WAIT-UNTIL TRIP 2.5 PM WAIT-UNTIL TRIP 3.5 PM WAIT-UNTIL TRIP 4.5 PM WAIT-UNTIL TRIP the robot to make several trips during the day. without having to tell it to do so each time. We can schedule the trips when de- sired using the words AM, PM, and WAIT-UNTIL. WAIT-UNTIL simply waits in a delay loop until the current time is identical to the desired time. AM and PM set the desired time. Time is specified in hours, so minutes must be expressed as fractional hours. For example, 8,5 AM is 8:30 am. The entire MAILBOT program is shown in Listing 6. You can extend RCL to deal with addi- tional hardware and to provide greater software flexibility. FORTH gives you the freedom to experiment and add to the ca- pabilities of the system. R-E 80 STEREO RECEIVER continued from page 44 The IC's AGC function was noi used in the design. Instead, pin 16 was terminated by R40andC33. A 10.7-MHz tuned circuit is formed by L7. C3iS. and C37. Resistor R4I acts as a swamping resistor to obtain the wide bandwidth of the quadrature circuit, C37, C38, and L7. Drive voltage from pin 8, IF out. to pin 9. quadrature detector input, is delivered via L6. The value of that induc- tor is somewhat critical for proper squelch-circuit operation. It should be be- tween 18-22 p.H. We had an 18-u.H unit on hand so it was used. A load for the AFC circuit is provided by R43, and R42 biases the audio circuit in the iC, Capacitor C38 is used to tune the quadrature circuit to 10.7 MHz. It is adjusted for best received audio and zero DC voltage across R43. Recovered total modulation is present at pin 6, It contains the FM baseband and the SCA signal. The baseband audio is taken off through R44 and C39. The baseband-audio amplifier is built around Q6, a 2N3565. It is set up for a nominal gain of about 5 (the ratio of R44 to R46 is the approximate gain of this stage). Resistors R45 and R46 bias Q6 to about 6 volts at I mi Hi ampere. R47 is a load resistor. About 2 volts of baseband audio is present at the collector of Q6. Audio from Q6 is fed to two separate circuits. One circuit is an SCA demod- ulator; the other is an FM stereo decoder. SCA demodulation Audio from Q6 is fed to an SCA take- off R-C high-pass filter made up of C40. R48, R49, C41, C42. and R6S. That filter substantially attenuates audio compo- nents below 50 kHz. The SCA demodulator, 1C2, is an LM565 phase-locked loop. It contains a VCO (Voltage Controlled Oscillator) and phase detector comparator. If a signal of sufficient amplitude (about 100 millivolts) is fed into pin 2 or 3 of that device, and its frequency is sufficiently close (say within ±30%) to the VCO frequency, the VCO will lock to the input frequency and track it; that is. the voltage that controls the VCO will follow any changes in the fre- quency of the input signal. The control voltage for the VCO is present at pin 7 and is a linear function of the input-signal frequency. Therefore, the LM565 can function as an FM detector with no exter- nal inductive components required. (At the SCA-subcarrier frequencies of 67 or 92 kHz. inductors can become rather large and somewhat costly. It is therefore to our advantage to eliminate those coils, and their alignment.) The LM565 is biased by external re- sistors RSI, R52, R53. and R54. The VCO frequency is determined by C43 and the resistance of R72 and R55. Theseitim: of R72 is adjusted so that the VCO I're- quency. which can be measured at pin 4. is near 67 kHz. Adjustment of R72 is not critical, and simply adjusting it for clearest SCA re- ception is adequate. (If 92 kHz operation is desired, R55 should be changed to about 6.8K.) Capacitor C44 is used as a loop filler for the phase- locked loop. Au- dio appears at pin 7 of the LM565. A de- emphasis network made up of R56, C45„ RS7. and C46 will suppress any 67-kHz components and attenuate high-frequency noise. An audio-amplifier stage, Q7, brings up the detected audio level to about 500 mV. From the amplifier, the signal is sent to the selector switch. S2, for routing. FM decoding Audio from Q6 is also sent, via block- ing capacitor C49. to 1C3. an LML310N FM-stereo multiplex decoder. The LMI310N contains a VCO, a phase- lock- ed loop for regenerating the 38-kHz stereo su be airier, a lock detector used as a ster- eo-indicator circuit, and a decoder circuit for deriving the left and right audio chan- nels. The internal VCO operates at 76 kHz and the 19-kHz and 38-kHz signals are derived from an internal frequency divider. No indicators are required and alignment consists simply of adjusting R73 for a 19-kHz signal at pin 10. Getting back to the circuit. C53, R62, and C54 form a compensating network for IC3"s internal phase-locked loop. Capaci- tor C50 is the loop filter for the phase- locked loop. The network made up of C55, R63. and R73 control the center frequency of the internal VCO, which should be 76 kHz. The 19-kHz pilot signal (derived from an internal divider) is avail- able at pin 10 for test purposes. Audio output appears at pins 4 (left) and 5 (right). Resistors R64 and R65 serve as loads for the internal audio amplifiers. FM-audio de-emphasis is provided by C56 and C57. The right and left audio from pins 4 and 5 is fed to S2. The audio amplifiers in this circuit, 1C4 and IC5, are LM386N\s. They each provide about a 0.5-watt output, adequate for driving an eight-ohm speaker. Do not use speakers that present less than an eight-ohm load. The entire receiver draws about 125 milliamps at 12-volts (the recommended supply voltage). The supply should be regulated and have good filtering. A suit- able power supply is shown in Fig, 3. Next time That's all the room we have for now. Next lime we'll show you how to build, align, and use the receiver. The PC pattern will he presented at that lime. R-E Learn micro-processing with the new MICRO-PROFESSOR IP Students, engineers or technicians — upgrade your micro-processing skills with the new Micro -Professor IP. The MPF-1P features; • extensive software support • more built-in memory • improved keyboard • larger display Three tutorial guides help cover all capabilities. The ideal training tool! MPF-1P will deliver you into the growing world of micro-processing. Invest now! Plus-FREE GIFT ° n| v $199.95 O Check thii box for FREE Z-SG Mkroprotcssar Programming .'in J Interfacing textbook when you order within 7 days. $16.95 value. (Includi- $7,5(1 postage & lujiidliiiul For immediate action call TOLL FREE; 1-800-426-1044 Full money back guarantee. visa- F\/jj IViun-'iJ with optiunsl punier I I Dcpi RE0887 5326 9ch Ave. N.E. Scatlic. WA 98105-3617 CIRCLE 111 ON FREE INFORMATION CARD LEARN TV/VCR REPAIR f No Previous Experience +. Necessary Now you can train at home In spare lime for a mon- ey-making career as a TV/ VCR Repair Specialist, No need to quii your job or school. Wc show you how to iroublcshoot and repair videocassette recorders and TV sets, how to handle house calls and shop repairs for almost any make of television or VCR, You learn about TV receivers, tuners and antennas, way emission, the characteristics of sound, how electrical impulses are con* verted into a TV picture, and much, much more. Tools are included with your course so you can get "hands-on" practice as you follow the lesions step by step. Send for free facts about opportunities in TV/VCR Repair and find out how you can start making money In this great career, ( Experts show you what to do, how to do it^.guide you every step of the way! Everything is explained in easy*to*underst4nd language with plenty of drawing photo* and diagrams. But If there is ever anything In your lessons you don't under- stand, you can write or phone your instructor and you can count on getting an authoritative answer. Send for free facts and color brochure. Mo cost. Ho obligation. No salesman will visit you. MAIL COUPON TODAY i _ SCHOOL OF TV VCR REPAIR. DepL DE077 wuc .nfj Scranton, Pennsylvania 18515 Please send me free facts on how I can learn TV/VCR Repair at home in my spare time, No salesman will visit. Name . Age City/State/Zip Phone ( ] > o c GO ^-4 81 MARKET CENTER FOR SALE CO g z O DC r- O O o < EC RESTRICTED technical information: Electronic surveillance, schematics, locksmith! ng. covert sci- ences, hacking, etc. Huge selection. Free bro- chure MENTOR-Z, 135-53 No. Blvd.. Flushing, NY 11354- TV lunable notch filters, free brochure. D.K. VIDEO, Sox 63'6025, Margate, FL 33063. (305) 752-9202. FREE power supply with Assortment #103 (February '84 article, has printed circuit, TOKO C0i!s(4), 2N3904{2), BFQ85, 7812, 74123, JVSC1330. 1N914, 1M5231B. TELE- ASE-MAST ASSORTMENT #301 (October Article) Printed Circuit with all IC's, tran- sistors, diodes. Only S25.00'each assort- ment. Five/$112.50. Shipping S3. DO. 1 (800) 821-5226 Ext. 426. (orders), or write JEM RHODES INC., P.O. Box 3421. Bristol, TH 37625. DESCRAMBLER catalog all makes. Special com- bo Jerrold 400 and SB3 $165. New cable de- scrambler kit $39.00 (assembles in half hour). Send $1.00. MJ INDUSTRY, Box 531, Bronx, NY 10461. TUBES! 59c, Year guarantee. Free catalog. Tube tester $8.95 CORNELL, 4215 University, San Di- ego, CA 92105. IS it true... Jeeps for S44 through the government? Call for facts! 1 (312) 742-1142, ext. 4673. OLDTIME radio programs on high quality tapes. Comedy! Adventure! Music! Free catalog. CARL F. FROELICH, Heritage Farm. New Freedom. PA 17349. LINEAR PARTS— transistors: MRF454 $15, MRF455 $12, MRF477 $11, MRF492 S16.75, MRF421 $22.50, SRF2072 $13, SRF3662 S25, 3800 $18.75, 2SC2290 $19.75, 2SC2879 $25. Tubes: 6KD6 $10.50, 6LQ6 $9.75, 6LF6 S9.75, 8950 $16.75. Best prices on Palo mar road noise mics, Ranger AR330Q. New 16-page catalog listing radio/amplifier tricks — channel modification, PLL- sliders, peaking for range, hard-to-find linear parts — mail $1.00 to: RFPC, Box 700, San Marcos, CA 92069. For same day parts shipment, call (619) 744-0728. TUBES - 2000 TYPES DISCOUNT PRICES! Early, hard-to-lind, and modern tubes. Also transformers, capacitors and parts for tube equipment. Send $2.00 tor 20 page wholesale catalog. ANTIQUE ELECTRONIC SUPPLY 688 W. First Sl.'Tempe, AZ 85281*602/894-9503 CABLE TV converters. Scientific Atlanta, Jerrold. Oak, Zenith, Hamlin. Many others. "New" Video Hopper "The copy killer," VHS -wireless remote 5239.00. Visa, M/C & Amex accepted. Toll free 1-(800) 826-7623. B&B INC., 10517 Upton Circle, Bloomington, MN 55431. BUILD your own pro monitors 32 pg. 5 part man- ual discloses design criteria utilized by major man- ufacturers of pro monitoring systems. Blueprints included! $25.00 complete to: BRIX ENTER- PRISES INC., 2419 Richmond Road, S.I.N.Y. 10306. SCANNING disk television. Read all about it! "The Mechanics Ol Television." (1987) 182 pages $20.00 postpaid. TESLA ELECTRONICS, 835 Bricken, Warson Woods, MO 63122. LEADER LFC-945 signal level meter $425.00. (312) 771-4661. TUBES, name brands, new, 80% off list, KtRBY, 298 West Carmel Drive. Carmel, IN 46032 ATTENTION looking for surplus test equipment sig- nal generator voltmeter oscilloscope. J.B. ELEC- TRONICS, 9518 Grand, Franklin Park. IL 60131. TEST equipment, reconditioned. For sale. $1.25 for catalog. WALTER'S, 2697 Nickel. San Pablo. CA 94806. (415) 724-0587. OLD radio TV schematics. Send $1.00. make, model.RADIO MAPS, P.O. Box 791, Union City, CA 94587. ROBOT! kits. Books and Plans! Learn to build your own robots. Free catalogs contain hundreds of af- fordable robot systems, Explore the world of robotics today. Catalog: CEARGS-ROBOTS!, POB 453, Peterborough, NH 03458. (603) 924-3843. LATEST high-performance op-amps, power mosfets. First quality. Send stamped envelope for list. ANZA INSTRUMENT CO.. Box 60907, Palo Alto, CA 94306. CABLE television converter, descrambler and wireless remote control video equip- ment accessories catalog free, CABLE DIS- TRIBUTORS UNLIMITED, 116- Main Road, Washington, AR 71862. LASERS, components and accessories. Free cata- log, M.J. NEAL COMPANY, 6672 Mallard Ct„ Ori- ent. OH 43146. CB RADIO OWNERS! We specialize in a wide variety of technical infor- mation, parts and services for CB radios. 10M- FM conversions, repairs, books, plans, kits, high-performance accessories. Our 11th year! Catalog $2. CBC INTERNATIONAL. P.O. BOX 31500RE. PHOENIX. AZ 85046 SUPERFAST morse code supereasy. Subliminal cassette. $10.00 Learn Morse Code in 1 hour; amaz- ing new supereasy technique $10. Both $17. Moneyback guarantee. Free catalog: SASE. BAHR, 2549-E3 Temple, Palmbay, FL 32905. TUBES, new, unused. Send self-addressed, stamp- ed envelope for list. FALA ELECTRONICS, Box 1376-2, Milwaukee, Wl 53201. TUBES: "Oldest", "latest". Parts and schematics. SASE tor list STEINMETZ, 7519 Maplewood Ave,, RE Hammond, IN 46324. CABLE-TV converters and de scram biers. Low prices, quality merchandise, we ship C.O.D. Send S2.00 for catalog. CABLETRONICS UNLIMITED, P.O. Box 266. South Weymouth, MA 02190. (617) 843-5191. Upgrade CD players, other equipment with Au- dio Amateur, world's only audio construction quarterly, S18'Year; S3Q.two. Satisfaction guar- anteed. MC VISA (603} 924-9464; checks to Box S76, Dept. E77, Peterborough, NH 03458-0576. ZENITH SSAVI, ready to go $100.00 plus shipping. order C.O.D. 1 (305) 752-9202 FREE sample! Discover Apex screwdriving bits, ac- cessories. Sensational fit. remarkable toughness, amazing durability. Write today! R, SHOC KEY'S, 5841 Longford, Dayton, OH 45424. DECODE nearly any Gated Pulse signal with our new super simple circuit Works on In-band, AM or FM pilot tone — use with Hamlin, Jerrold, Sylvania. Complete plans and theory only $13.50 plus $1.50 P&H. ELEPHANT ELECTRONICS INC., Box 41665-J. Phoenix. AZ 85080. (602) 581-1973. VIDEO scrambling techniques, the original "secret manual" covers Sinewave. Gatedpulse, and SSAVI systems. 56 pages of solid, useful, legible informa- tion, only $14.95 ELEPHANT ELECTRONICS INC., Box 41865-J, Phoenix, AZ 85080, (602) 581-1973. .P^, WRITE FOR .JllkMcGEE'S SPEAKER & ELECTRONICS CATALOG 1001 BARGAINS IN SPEAKERS toll free 1-600-346-2433 for ordering only. 1901 MCGEE STREET KANSAS CITY, MO. 64103 WHOLESALE car stereos alarms electronics Huge selection. Catalog $1.00. NORMAN ELEC- TRONICS, Box 3579A Ridgewood, NY 11386. BATTERIES rechargable, gel-lead, pure lead Ni- cads send for free complete listing of batteries by amp/hr and voltage. ENERGY CONTROLS, 20451 Stephens SI., Clair Shores, Ml 48080.' (313) 775-3492. RESISTORS: 1/4 watt, 5%, all standard values to 4.7 meg. 20 pieces of one value $1.00 postpaid. RAHTEC, Box 36064, Minneapolis, MN 55435. PCB volume fabrication from Hong Kong INTEG- RITY TECHNOLOGY, 105 Serra Way. #230, Mllpitas, CA 95035-0604. SURPLUS computers: Multibus, Versabus. S-100, VME, AMIGA, Atari ST — boards, power supplies, test equipment, terminals, disk drives, complete systems. Free catalog. Trading IBM-compatibles for unwanted systems: buying unwanted equipment. HIGH-TECH SURPLUS, (203) 723-5694. 490 Wooster Street, Naugatuck, CT 06770, TAP complete set volumes 1-84 quality copies Si 00 ppd PEI, P.O. Box 463, Mt. Laurel, NJ 08054. PHOTOFACT folders, under #1400 $3.00. Others $5.00, Postpaid LOEB, 414 Chestnut Lane. East Meadow, NY 11554. EQUIPMENT liquidation: Surplus remote-control converters, with touch-type remotes, favorite chan- nel programmable, digital PLL synthesized, auto- matic fine tuning, switched TV outlet, 30 day warranty, $35.00. Quantity package 25+ units $15.00(0), field run. as is (includes service manual). Oak minicode N1 2 decoders quantity package 25 + units $20.00<&, field run. as is. "Beeping . notch filter CH3 decoders, 30-day warranty, $15.O0(B, quantity 25+ $10.00(u\ field run, as is, shipped prepaid. All others add $3.00 unit shipping. Send money order to ELECTRONICS PRESS, PO Box 10009, Colorado Springs, CO 80932. LIFETIME wnfinaHTY Quality Microwave TV Antennas High Gam System S99. 95 ( < stuppmg) I AMR Higti Gain Syslem S79.95 ( ■ shipping i Multi-Channel 1.9 lo 2 1 GHz Dealerehlpi. Oty . Pricing, Replacemenl Pirtt pmiiips-Tecrt Electronics P.O. Box 8533 • ScotlidaJe, AZ 85252 (602)947-7700 IS3.00 CrrtB ill pHom ordcrttl MlsttrCKll • 'Ir.i • COO'S TI-99'4A soltware/hardware bargins. Hard to find items. Huge selection. Fast service. Free catalog. DYNA, Box 690, Hicksville, NY 11801. Z-TAC Zenith cable unit only $175.00. Buy 5 at only $150,00, or 10 at only $125.00. These units do not use block converters, we install our own VHF tuner for excellent picture quality. UPS daily. COO accept- ed. All orders shipped 2nd day air. 90 day warranty on units. Call for information or free catalog or write AMCOM, P.O. Box 68391, Virginia Beach, VA 23455. Phone: (804) 456-5505. FREE "National Semi Conductor" pocket cal- culator and catalog of car stereo, C.'s, radar detec- tors, alarms, accessories. Dirt cheap! Send $4.00 for postage and handling, ELECTROMANIA, 51 B Sunrise Highway, Lynbrook, NY 11563. 82 DO YOU REALLY GET THE BEST BUY THEM? et's face it: There will always be some outfit that can undercut a published price. They do it by having no overhead, and no responsibility to you, the consumer. So, you want that Jerrold 450 combo? The one that Pacific Gads CD.. IRC, is offering for s 1 99 M ? Weil, that's a good price, but here's what I'll do.. ." What may happen is that you may save a couple of bucks at the time. But suppose there's a problem (and it happens to the best of them,) and you call that "Dealer"... This could be what you'll hear: "No, Steve isn't here. He moved out, the bum! And he owes me E 437 w on the phone bill! No, I don't know about any guarantees on your Gerald, who's that? Listen, if you see that creep..." etc. At name CMM CO., you've got an established company who will be here for you, time after time. We may be tough competitors, but we've got a soft spot for our clients! Try us, and be treated right — and we'll prove it by giving a one-year warranty on everything we sell. Check our prices on scientific Atlanta units) ITEM 1 UNIT 10 OR MORE 29.00 18.00 Panasonic Wireless Converter tour best buy) 8800 6900 88.00 69.00 169.00 119.00 29.00 18.00 89.00 58.00 99.00 70.00 'M-36 B Combo unit (Ch 3 output only) 99.00 70.00 109.00 75.00 89.00 58.00 ITEM *Minicode (N-12) with Van Sync *Minicode VariSync with Auto On-Off ,.,..-,.,,. .... Econocode {minicode substitute) Econocode with VariSync •MLD-1200-3 ICh3 output) , •MLD-1200-2 (Ch.2 output) •Zenith SSAVI Cable Beady Interference Filters (Ch.3 only) ,.,.,,.,.,... •Eagle PD-3 Desorambler (Ch.3 output only) . •Scientific Atlanta Add-on Replacement Descrsmbler. 1 UNIT 99.00 14S.O0 79.00 89.00 99.00 99.00 175.00 24.00 119.00 119.00 10 on MORE 62.00 105.00 52.00 56.00 58.00 58.00 125.00 14.00 65.00 75.00 CHECK US OUT— WE'LL MEET OR BEAT THE OTHER'S ADVERTISED WHOLESALE OR RETAIL PRICES! Pacific Cable Co.. inc. 7325% Reseda Blvd., Dept. R-08 Reseda, CA 91335 (81 8) 71 6-591 4 . (81 8) 71 6-51 40 • NO COLLECT CALLS! • IMPORTANT • When ordering, please have the make and model number of the equipment used in your area— Thank you! *Call for availability Prices subject to change without notice Jenrdd is a registered trademark o' General Instruments Gctp Quantity Hem Output Channel Price Each TOTAL PRICE SUBTOTAL California Penal Code #593 -D forbids us from shipping any cable descrambling unit to anyone Shipping Add £3.00 per unit residing in the state of California. Prices subject to change without notice COD & Credit Cards— Add 5% PLEASE PRINT TOTAL _ City . -Zip. D Cashier's Check Acct # _ Phone Number ( D Money Order )- □ C.O.D. . Exp Date — DVi$a □ Mastercard Signature- FOR OUR RECORDS DECLARATION OF AUTHORIZED USE — I, the undersigned, do hereby declare under penalty of perjury lhat all products purchased, now and in the future, will only be used on cable TV systems with proper authorization from local officials or cable company officials in accordance with all applicable lederal and state laws. Dated: _ Signed: > C o c CO -I CO CD 83 « o z o <r H o Q < CABLE-TV DESCRAMBLERS. You name it! You'll get it! Specializing in hard to find equipment. Special: Scientific Atlanta com- bination with remote $229. C.O.D. any- where. (916} 541-8461. NATIONAL CABLE/ SO. SHORE INC., 1512 Roswell Road # 229, Marietta. Georgia 30067 PLANS AND KITS BUILD this five-digit panel meter and square-wave generator including an ohms, capacitance and fre- quency meter. Detailed instructions $2.50. BAG- NALL ELECTRONICS, 179 May, Fairfield, CT 06430. HI-FI speaker systems, kits and speaker compo- nents from the worlds finest manufacturers. For oe- tinners and audiophiles. Free literature. A&5 PEAKERS, Box 7462, Denver, CO 80207. (303) 399-8609. VOICE disguisers! FM bugs! SWL active antenna! Receivers! More! Catalog SI. 00 (Refundable): XANOI ELECTRONICS, Box 25647, Dept 60P. Tempe, AZ 85282. PROJECTION TV...Convert your TV to project 7 foot picture. Results comparable to $2,500 proj- ectors... Total cost less than $30.00 plans and 8" lens $21 .95... Illustrated information FREE...MAC- ROCOMA-GL, Washington Crossing, PA 18977. Creditcard orders 24hrs. (215) 736-3979, CRYSTAL radio sets, plans, parts, kits, catalog $1.00. MIDCO, 660 North Dixie Highway, Hol- lywood, FL 33020. CATALOG: hobby/broadcasting/1750 meters/ham/ CB: transmitters, antennas, scramblers, bugging devices, more! PANAXIS, Box 130-F8, Paradise, CA 95967. FREE catalog 99-cent kits — audio, video, TV. computer parts. ALLKIT, 434 W 4th St., West Islip, NY 11795. Cable TV Converters Why Pay A High Monthly Fee? Jerrold Products include "New Jerrold Tri-Mode," SB-3, Hamlin, Oak VN-12, M-35-B, Zenith, Magnavox, Scientific Atlanta, and more. (Quantity dis- counts) 60 day warranty. For fast ser- vice C.O.D. orders accepted. Send SASE (60 cents postage) or call for info (312) 658-5320. Midwest Electronics, Inc./, HIGGINS ELECTRONICS, 5143-R W. Diversey, Chicago, IL 60639. MC/ Visa orders accepted. No Illinois orders accepted. Mon.-Fri.-9 A.M. -6 RM.CST WIRELESS remote cable converters $60.00 with purchase of selected video Kit. $50.00 boards and parts for video and hobby projects from magazines and other sources. SA turn on kit $40.00. Video dechipher kit $75.00 Call or write for list and details. WIZARD, 1(419) 243-7856, 24 East Central. Toledo, OH 43606. JERROLD gated pulse theory. Twetve information- packed pages covering Dl & DIC converter opera- tion. Includes introduction to trimode system. $6.95 plus $1.50 postage and handling. ELEPHANT ELECTRONICS INC., Box 41865-J, Phoenix, AZ 85080. (602) 581-1973. DESCRAMBLE the latest video cassette copy- pro- tection scheme. Our simple line zapper circuit takes the jitter out of your picture. Complete plans and theory only $13.95 plus S1 .50 postage and handling. PC board and complete kits also available. ELE- PHANT ELECTRONICS INC, Box 41865-J, Phoe- nix, AZ 85080. (602) 581-1973. MINIATURE electronics devices, like James Bonds. Catalog $2.00. F&P ENTERPRISES, Box 51272, Palo Alto, CA 94303-L //■T Parts // express HARDWARE AND ELECTRONICS MAGNIFIER LAMP ■ 4" dioptej magmiying IMvf. - U»a up to * ffl wall t»*lb (nel included! UL iihim], 11 7VAC *26 95 COPPER CLAD PC BOARD 9" i fl Douole Sided W55-30Q 1B' r x 12" OoublH S*de0 $-|5D S395 HS-232 DATA SWITCH • 3 {Kttilion. rotary Iff* ■ Fully shielded. FCC appiOWf *27^ PIONEER HORN TWEETER • Frequency response l BOO Id 15.QOQH2. ■ P{hv«r handling capabil- ities H5W RM$, r«omn1 Irequency *2/fi-£S0 *6« $5*) 12" PIONEER WOOFEfl * Power 65W RMS * 11 Or, rnipni ■ 251O25O0 Hi reipanM ■ VA-" valet coil t 15 s» s-i.395 TOROIDIAL TRANSFORMER :^:.:-::n,,i :. ' I1MMM >«» *9 M FREE CATALOG Our new 56 page catalog contains thousands of items lhat you need every day for do-it-yourseiJ projects, produd engineering, electronics repair and more. Call us today for your f rw copy and start saving! 300 PIECE CAPACITOR KIT * A y:M" asioi[r?.nrl Cif CFIdrdfl viluae end wooing voltign l?%2ludes «l*ctro.yiies, can nuts. 149s CALL TOLL FREE 1-800-255-3525 In Ohio: 1-800-322-3525 Local: (513) 222-0173 | • 1 5 ** mofttr UK* QuwiiM * tlQ.Q0fntnknwn . onhf. ■ COP ordin *c#*ptt4. 2* hour shipping. - Shipping cfwge = UPS chart rat* (13,50 mln- | 3mum ct\*t$*). Houra B:30 i.m. < p.m. EST H-F. PARTS EXPflESS INTL INC. 349 E«il Firal St DiylH). OhiD 15402 CIRCLE 181 ON FREE INFORMATION CARD When someone in your family gets cancer, everyone in your family needs help. Nobodj- knoQQ better than wc (to how much help anrj understanding is needed. Thai's why our service and rehabilitation programs emphuirc ihc whole taJhily, not |usi the cancer patient. Among our regular services ivc provide in formation and guidance to patients and Families, transport paricnu to and from treatmeoi. supply home can? items and assist patterns in their return to everyday life. tjfc Is what concerns us. So you can see wc are even moje ihan the research organi- zation we are so well known (o be No one faces cancer alone. f AIWEBKAN COMCSR SOCIETY SUPER Octopus circuit tester; plans and user's guide; $5.00 to VIEWPOINT, 8405 Glencrest, Sun Valley, CA 91352. ELIMINATE light and dark from copying new video tapes. Schematic S5.95 circuit board $5.00. BLED- SOE, TO Box 3892, Central Point, OR 97502. DETECTIVES, experimenters. Exciting new plans. Hard to find micro and restricted devices. Large catalog $5.00 refundable on 1st order. WILSON, P.O. Box 5264, Augusta, GA 30906. ELECTRONICS surveillance book on eavesdrop- ping investigation surveillance includes civil liberties outlined by congress (Office of Technology Assess- ment). Also covers infrasonic sound (sound below hearing) send $17.00 to: COUNTERMEASURES, P.O. Box 1021, Rowlett, TX 75088. RADIO, free power, modern day crystal set. Send for info MERIDIAN SYSTEMS, Box 116, Eliot, ME 03903. ULTRASONIC ranging system measures dis- tances from 6" to 35'. I/O is TTL compatible, can be connected directly to most computers. Experi- menter's kit includes one SN28827 ranging module, one Polaroid 50KHz electrostatic transducer, and user's manual with data sheets. Great for alarms, computer mapping, robotics, etc. $59.95 + $2.00 postage. S2.50 for COD. I.O. MICRODEVICES, P.O. Box 2386. Canoga Park, CA 91306, (813) 348-8312. PAY TV AND SATELLITE DESCHAMBLING NOW 120 PAGES Schemaiics. theory, bypasses. 13 cable. 7 satellite systems including After Dark Vitfre SH.S5. fi Ed Update Only S8.95 fnperuneiHj With V.d- EOCifj^lfi^ LalCSl Ctlu \S dcr iirj, — s. :"; «.C lii: : i-; :j d,-:!;i y,'J j)f> '';■::!■ "Y two-way. security systems, design S12.95. MDS'MMDS HandbeiQlt . for micioMtfe hackers SS.SS Bmlfl SalclHi: Sy-;:---n ■:■. i ■:■;:■;_ lUftC J v !H.;i Anyj>$26 Summer alslog SI . Sho|iki Electronics Corp. 1327A Niagara St.. Niagara Falls. NY 14303. COD s 716-284-2163 STRANGE stuff. Plans, kits, new items. Build satel- lite dish $69.00. Oescramblers, bugs, adult toys. Informational photo package 53.00 refundable. Dl- RtJO CORPORATION, Box 212, Lowell. NC 28098. PAC-TEC enclosure specified in Feb. '87 R-E article on Tri-Mode. Pre-d rilled.. $24. 95 plus 52.50 S&H. VISA/MASTERCARD accepted. Call (617) 339-1026 or send to THE HOBBY HELPER, P.O. Box 308, Bridgewater, MA, 02324. ULTRASONIC pest repeller; Exceptional design! Complete quality kit S25.0O, assembled $30.00. UFO DETECTING BOOK: Electronic projects, the- ories, schematics. $6.00 (NY I 7.5%). UFONICS. Box 1847-R, W. Babylon, NY 11704. MELODY IC, Piezo element and application sheet only $3.00 BELL CERAMIC INDUSTRIES, INC., 31 Passmore Avenue, Unit 28, Toronto, Ontario, Canada M1V4T9. DESCRAMBLING, New secret manual. Build your own descramblers for Cable and Subscription TV. Instructions, schematics for SSAVI, gated sync, sinewave. (HBO. Cinemax, Showtime, etc.) $8.95 +• $1 .00 postage. Catalog $1 .00. CABLETRONICS, Box 30502 R, Bethesda, MD 20814. SATELLITE descrambting manual, Video Cypher II. Schematics, thorough explanation of digital audio encoding, EPROM code, DES. (HBO, Cinemax, Showtime.) $10.95 +$1.00 postage. Catalog S1.00 CABLETRONICS, Box 30502R. Bethesda, MD 20814. CABLE television converter, descrambler and wireless remote control video equip- ment accessories catalog free. CABLE DIS- TRIBUTORS UNLIMITED, 11S-P Main Road. Washington. AR 71882. INVENTORS INVENTORS! Can you patent and profit from your idea? Call AMERICAN INVENTORS CORPORA- TION for free information. Over a decade of service. 1-(800) 338-5656. In Massachusetts or Canada call (413) 568-3753. 84 SATELLITE TV CABLE TV Secrets — the outlaw publication the ca- ble companies tried to bar. HBO, Movie Channel, Showtime, descramblers, converters, etc. Sup- pliers list included S3. 95. CABLE FACTS, Box 711- R, Pataskala, OH 43062. SATELLITE TV receiver kits! Instructions! Sche- matics! Catalog $1.00 (refundable): XANDI ELEC- TRONICS, 8ox 25647. Dept. 21S, Tempe. AZ 85282. DESCRAMBLER build our low cost satellite TV video only descrambler lor all major movies and sports. Uses all Radio Shack parts. Order P.C. board and instructions by sending cheque, money order, or Visa for $35.00 U.S. funds to: VALLEY MICROWAVE ELECTRONICS, Bear River, Nova Scotia, Canada, BOS-1BO. (902) 467-3577 Mu ti-Channe Microwave T.V. Receivers u VISA/MC/COD t .9-2.7 GHz Parabolic Dish 40-cJBGain LIFETIME WARRANTY Com pi el e Syslem SB9.95 (Shipping Incl ) Replacement Components & Expert Repairs Available K S S ELECTHDNICS Call now tar same P.0.BDX34522 toy sMppinri! PHOE MX. A Z BS057 [B02) 230-0641) For Dealer Rates Call 602-888-4080 SATELLITE TV equipment. Buyers guide, discount prices. $3.00 N.E.C.S. INC., Box 22808-R1 , Little Rock, AR 72221. SATELLITE scramble newsletter, non-profit pub- lication, descrambler sources, $1.00, MICHAEL THOMPSON, Box 4508, Dieppe. Canada, E1A-6G1. 59 degree brand name LNA's! LNB's! Ku-Band LNB'slDiscount pricing! Catalog $1.00 (refundable): LNA-RE, 201 E. Southern, Suite 100, Tempe, AZ 85282. NEWII INSTALLATION and REPAIR of VfdeoCipher* 2000 and 2100 ThtOnty VCR Jrstmctionaf Video Program Demonstrating: Normal & Special Installation * Setting External Controls • Preforming Internal Adjustments • Determing and Repairing Common Board Problems * Replacing Parts Cohered by Epoxy • Static ft-ecoutions & Special Soldering Techniques. Using PHOTIC; the electronic test device for the professional TVftO dealer Everything you've wanted to know shown tor the nrst time, for only 159.95 S*- pc-ng IS SO Send check crKkltS SO COO EC«»\ certified chec* or WC on COO J Hocredrt caret l«*™v PO'I N y add n UK TRVO dealers receive SI 0.00 rebate towards 1st purchase of PROTEC plus discounts worth more than (50.00 on soldering equipment and accessories. TESTRON, Inc.. ckpt Rl, 184 Jencho luinpikt. Floral Part, N.y 1 1001 SOO-sai-lOOSot 301 Mhts-7dsys(ir,Nrt5lfr358-94H VIDEOCIPHER data disk, Apple II and PC dial (011)(52) (451)42268 (Mexico), 4-10 PM. CST. lor information. SCIENTIFIC Atlantia cable users series 8500 8550 get all channels instructions for simple modification costs under $10.00 to make. Complete instructions. Send $10,00 no checks to K.F. SPECIALTIES, PO Box 443, Forked River, NJ 08731 , SATELLITE systems $295 up. VISA/MC available Catalog $2. STARLINK INC., 2603- 6E Artie, Hunstville, AL 35805, 10ft Satellite system, remote controlled, tracker and descrambler with 1 yr free subscription to 20 channels. $1,495 plus UPS, VISTA VISION, 1 (602) 458-5482 after 10 a.m. PRINTED CIRCUIT BOARDS CIRCUIT boards prepared from layouts or CAD files Call for price list (301) 987-4023. PEL, 1205 Generals Highway, Crownsville, MD 21032. iNUTS&VOLTSi O A Z I W P.O. Box 11H-6 Ploeorvtia, CA 32B7D GIVE YOURSELF A BREAK — A PRICE BREAK' NUTS & VOLTS WILL $tf9 Y'DU MONEY □N ELECTRONIC PARTS £ EQUIPMENT PM SHOW YOU WHERE TO FIND UN rDUE, UNUSUAL AND HAFTDTO FIND ITEMS SUBSCRIBE TODAY! .*.,:,■., -rj^l.-Hr. 2r*Glf**M-*<-UIA Oil Tim HDH T*B tun 11100 LiUffi.C tW« ^A t/MtitiutPiiMiatitfl ht Jht ftyi»jAi/jr% QfRtetottitipfynttit BUSINESS OPPORTUNITIES MECHANICALLY inclined individuals desiring ownership of small electronics manufacturing busi- ness— without investment. Write: BUSINESSES, 92-R, Brighton 11th, Brooklyn, NY 11235. PROJECTION TV. ..Make $$$s assembling proj- ectors... easy... results comparable to $2,500 proj- ectors. Total cost less than $30,00, PLANS, 8" LENS and dealers information $20.50. Illustrated information free. MACROCOMA-GLX, Washington Crossing, PA 18977. Creditcard orders 24hrs, (215) 736-2880. ELECTRONIC ASSEMBLY BUSINESS Start home, spare time. Investment knowledge or experience unnecessary. BIG DEMAND assem- bling electronic devices Sales handled by profes- sionals Unusual business opportunity, FREE: Complete illustrated literature BARTA. RE-0 Bux 24 B Walnut Creel( . Calif. 94597 HOME assembly. Assemble PC boards for video accessories. We supply materials. No experience needed, 57.50 per hour. Send self-addressed stamped envelope, to: MICRON-ELECTRONICS, Box 4716, Akron OH 44310. EASY, lucrative. One man CRT rebuilding machin- ery. Free info: (815) 459-0666 CRT, 1909 Louise, Crystalake, IL 60014. GREAT VALUES 'FAST SHIPPING 'QUANTITY DISCOUNTS MULTIFUNCTIONAL LED D.P.M. SM " r>15V 2A REGULAT ^n n J MEASUREMENT RANGE DC. VOLTAGE: ImV - lOOOV A.C. VOLTAGE: ImV - 1000V DLGITALTHEftMOMETER; (fc D.C, CURRENT: 1 uA - 2A CAPACITOR METER: 1 pF INFRARED REMOTE CONTROL UNIT TY-41 MKV Kii SSB.50 m as. tamed M9.50 > m ssmjm ,chti J£ TO fittf c<* Krt ....... S30.00 DIMENSIONS: 3 3Mr*n 17/11" x4 1/16" AtuhrrWud with i«t«J ..S36.00 80W+80W DC LOW TIM PRE-MAIN AMPLIFIER TA-SOO . KIT .555.30 METAL CABINET/* FORMER -S3oY$Ho'.BQ SUPERIOR ELECTRONIC ROULETTE TERMS: 510 min order »S20 min chars* care) order "Chc-i:*. money Order or uhtiT crticr teeeDiad • We thip 'JPS Ground * Add I OS of TOEil Otdtf ifTiTi $3.50 r lor ihippnij. ouindi USA add 20% Imin SS.O0I ■ CA nfkjcnti add talei lax • All merchandtw subject to prior sair •Pncrt an rubject Is channt bvnh^.jl r.nli-cn * Any ftOQdt urr-veM 1g p«j dflfccUve-, MU&T BE RETURNED IN OFtlGlNAL FORM WITH A COPY OF YOUR INVOICE WITHIN 30 DAVS FOR REPLACEMENT. MARK V ELECTRONICS INC.. 218 EAST MAIN STREET, SUITE 100. ALHAMBRA, CA 91801 TELEX 3716914 MARK 5 *1* Output voMaqe Ft adiuiiaoie Irom O-i&v DC. two currem ■■ r rsngq areavaHjfclrj iw iclcdion; 2COmA of ?A. *l* An e^aLtCrilcCS ptoiccvon [ystum il WKially ^ei^rcrt, f 'i3E (Qund 4n d & iDo/klmg light wiM tpptir whrn the output i* overloaded »I* High icabilrty and reliability if ixmlled by qmployinq high cpiaJiiy voltegt regulated IC. ^ Kino-ifza meter makiesi thfl ne-tfkng « f wfl1l*B* » ni * cu'tent mpre tltirly j- J Kcvrvtely. <fy A r(f mco CIH. mfllfl T anrl all jccesinjy arc cnclatcd lor bOlh kit a" J Mumblod form, ll ■* mgil igitebl« far protafwnal or nrneteur dm, 20 STEPS BAR/DOT AUDIO LEVEL DISPLAY KIT ty-45 That nnw dniQ^ed iMidio level display unO -3 u-img a n£vM m cegracvet frtun from Nalional 5»FnicgnductciT lo drive 20 pieces of color LED'j, \^'rr- vui nv-- and rnd| an each channel, it prowidai two- Sycwi of display me-thocfi lar telacno-n 'bf' or "doi". The diicle-y rang* n from -57d-H t& OdB Kit is nood Iqi any amplHier Iram 1 war.u 10 200W • Powar supply requirei 12VAC Or DC. So, 1 ngreai lor can a> wail' Kit c&mts Hiih primed circuit board, ail LED 'f q]«ctrOnic ■: (::-;: ::.-;:'■ :; ::\.\:: 1 >.': and ■■,•.>.•;■:■•-<• (:■ i.!r.' 011 1 lArJ^ [j-n'i-si u-ai Irant panel. HIGH QUALITY PREAMPLIFIER WITH 10 BAND EQUALIZER .sji.ga i<H).0O 1-800-423-3483 TOLL FREE Onlv for orders paid bv Master or Visa card I INCAL: 1-800-521-MARK professional' color light controller SM-328 mm, '"•'""■ipK-rniiS OFF.. (PACI MON. INFORMATION: 1-818-282-1196 MAILORDER: P.O.BOX 6610 ALHAMBRA, CA91802 to 09 CIRCLE 93 ON FREE INFORMATION CARD 85 YOUR own radio station! AM, FM, cable. Licensed or unlicensed, BROADCASTING, Box 130-F8, Par- adise, CA 95967. PERSONAL computer owners can earn $1000 to $5000 monthly offering simple services part time. Free list of 100 services. Write: C.I. L.G.B., P.O. Box 60369, San Diego, CA 92106-8369. EARN thousands with your own electronics busi- ness, I do. Fiee proof, information. INDUSTRY, Box 531, Bronx, NY 10461. FLORIDA business lor sale. Electronic service sales, FLORI-DAY ELECTRONICS, 44 Avenue E, Apalachicola, FL 32320. (904) 653-9657. MAKE $$$ manufacturing electronic products! 30 + filans $5.00 complete! [Free details available) NRG NC, 11580 Oakhurst Rd.. Largo, FL 33544. EDUCATION & INSTRUCTION FCC Commercial General Radiotelephone li- cense. Electronics home study. Fast, inexpensive! ■Free" details. COMMAND, D-176, Box 2223, San Francisco, CA 94126. CASSETTE recorded home study for new General Class FCC license examinations. Seminars in Phil- adelphia, Detroit, Boston, Washington. BOB JOHNSON TELECOMMUNICATIONS, 1201 Ninth, Manhattan Beach, CA 90266. (213) 379-4461. A SINGER'S DREAM! WANTED INVENTORS! AIM wants— ideas, inventions, new products, improvements on existing products. We present ideas to manufacturers. Confidentiality guaranteed. Call toll free 1-(800) 225-5800 for infor- mation kit. rf i -V REMOVES VOCALS FROM RECORDS! How You can sing with the world's best bands! The Thompson Vocal Eliminator can remove most or virtually all of a lead vocal from a standard stereo record and leave the background! Write or call For a free brochure and demo record. LT Sound, Dept. R-l, P.O. Box 33fe\ Stone mountain, GA 30086 (404)493-1258 i INVENTIONS, ideas, new products wanted! Indus- try presentation/national exposition. Call free 1-(800) 528-6050. Canada, 1-(800) 528-6060. X831 . WANTED surplus inventories of ICs, transistors etc. No quantity too small or large. Call WESTERN TECHNOLOGY, (303) 444-4403. FAX (303) 444-4473. DESCRAMBLER MODULE COMPLETE cable-TV decoder in a mini-module. Latest technology upgrade for Jerrold SB-3 or Ra- dio-Electronics Feb. 1984 project. Available at very- low cost. For literature, SOUTHTECH DISTRIBUT- ING. 1-(800)-821-5226 ext. 130. NOTCH FILERTS NOTCH filters for any channel. Send $15.00 for sample unit. Specify output channel of converter. Money back guarantee. DB ELECTRONICS, P.O. Box 8644, Pembroke Pines, FL 33084. SCIENTIFIC ATLANTA & SB-3 SCIENTIFIC Atlanta cable converters (original units), models — 8500 and 8550, remote con- trol... $240. 00. SB-3 's... $74 .00. TRi-Bi'S.„$95.00. SBSA-3'S.. .$99.00. Zenith (Tag-ons)...$159.00. Jerrold-450 converters.. .$95.00. Dealer discount on units. Call— N.A.S., (213) 631-3552. ViDEO TAPE f" B S H ■■] COPYGUARD Eliminate the latest copyguard problems units from $59 9S to $169 es 'Dthp& 'Ekctronics (714J99S -6S6S 1 132 Ham ■>%, Otyigt, Co- SZ6&S DO IT YOURSELF TV REPAIRS NEW...REPAIR ANY TV...EASY. Anyone can do it. Write RESEARCH, Rt. 3, Box 601 R, Colville, WA 99114. CABLE TV TURN-ON'S "TURN-ON" boards for all models Jerrold 450s, Requires no internal modification or soldering, sim- ply plugs into existing connector. Fully guaranteed. Quantity discounts available. Call or write for infor- mation and prices. VIDEO SOLUTIONS, 3938 E. Grant, Suite 257, Tucson, AZ 85712. (602) 323-6072. CONSULTING SERVICES DIGITEK turns your ideas into hardware. Design and/or prototyping. Send SASE for free feasibility and cost analysis. No job too small. DIGITEK, Box 195 Levittown, PA 19059. (215) 949-2260. COMPUTERS TANDY computers! MSDOS, IBM, compatible. Dis- count prices! For quote or purchase call 1-800-36- SHACK. EDGEWOOD COMPUTER CENTER. CABLE TV D ESCRAMBLERS CABLE television converter, deserambier and wireless remote control video equip- ment accessories catalog free. CABLE DIS- TRIBUTORS UNLIMITED, 116-C Main Road, Washington, AR 71862. 00 o ■z. o rr h- < DC 86 INS2580 3.50 253QA CPU V» 2BQB CPU J. 75 Z80A CTC IJfi ZBOA DART 5.25 280A DMA 5,50 ZS0APIO 1.95 230ASI0 *.M Z8QB 510 9.85 I2C43 3.76 AMDJOOl 4.00 MH 2.75 B633 J.fiO MOO 1.75 I09S V:'l I •..-. : i. \--:_, n .95 ftoso a oo B1M-2 B»7 1203 6212 S714 B316 S3 34 6776 ■237-5 7,50 3.75 a.™ is.oo i>s a.js 1J50 3.3S 1.BO E.SO 3.95 0.7* 2.40 too 1.75 na-.c. Id «*fi 6950 1,75 fiS75 4.50 073301 12.00 8031 2.75 K9S J040 B750-A A251-A ■3*3 1 ,7t 12S5-A-5 1.85 (35 T 2 44 ■259 1*0 13T2A 4.76 82T5 9,00 1379-5 2.75 (384 2.M B288 4.75 eifii 12.55 8748 7.50 175 MS18450 5.B5 6.00 TMr5W27NL9.lW 750 &1000LS 8.60 RAM 'j 2018 1 .50 21L02-3 70 21QIA-4 1,60 71 1 IA 1 ,ti 2112 1 1.95 51 H? 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I 4( 74L5192 65 74L5191 85 74LS104 08 74L5I35 65 74LS1SO 55 74LSK7 .55 74L532I 55 PLEASE CALL FOR QUANTITY PRICING 74L5240 55 74LS2'! 61 74L5242 55 74LS243 65 74LS244 S5 74L5245 .75 74LS240 140 74L5247 75 74LS243 bL 74L525I 45 74L5253 .45 74LS257 39 74L525B 45 74L82S9 1 20 74L5260 45 74L8388 55 74Lt2^3 T5 74LS279 .39 74L82BD t 70 74L5363 56 74L52W 80 74L5393 80 74L5398 65 74LS320 7 TO 74L3J72 500 74LS323 240 74L83B5 39 74L8300 39 /4LS387 33 74LS388 33 74LS373 76 74LS3^4 76 741S37T 75 74LS380 45 74LS390 1.10 74LS303 .76 74L53>98 3 50 74LS440 2.00 74LS641 1 40 7415525 1 75 74L5H5 9* 74LS60S 1 45 74LS670 .95 S1LS9& 140 RCA, HC250D 60 WATTS SOLID ST^TE HYBRi D $34.95 LINEAR AND AUDIO AMP DISC CAPACITORS IOC IOV 10/f 1 DO 10046 TO 01UF15V 15.'5100 100rS500 LN4148 ■ I rv 3 ! ■* « IS; I 00 LA533U TBLOfiar >2 7AMD5. 17 tn REGULATORS 5595 32JK 1LA14&SI. 5 30 LM337 . i . % ,40 L7433BK . . 3407-6.0.0^.12. l5J8ar3*V 52 95 52 75 $3 75 &125 S DO 730 320T-5.13.15fl. 24 S .55 L141MFL ttamcicr F P 100 PhMO TtJ*ll FUd L£D"i 3" 1 VH'o*, 'ui«ii, ar A I'V.-. L >j Lt-Ji n*i;-li-rr , ll.[,"j, LED . . P-- ■. v~ .„, i; .... . , i : ULED92IH LCD MftDI 4fl P»ioia fla' I XfEJH II 5 OptO ll*i*T«fl *ii 45 Ditto Cwp-ti : It lilJ" RfiLAVS 5V SPST ,75 5V DPST (5 13VOPST 4,95 PRINTED CIRCUIT BOARD 4" k 5" DOUBIE 5lO£ D tPOJtV BOARDED I ■IB" THICK 560» 5S260 FULL WAVE BHID-GE PRV 3A Eh 25A 100 140 200 80 130 220 400 1 TO I 85 1 10 (00 130 I DO 440 DIP SWITCHES CTS 70(1 4 4 P;.„i ji GT5 306 7 TPotHiH^ CTS 306 8 8Poiihr>i CTS 70S. 10 lOPoiLlnDn I SILICON POWER RECTIFIERS Pflv 1A 3A 17A 50A 125A 340A ICO 05 14 15 em 500 ' <: 200 » 17 50 1 30 'IT' 400 09 25 65 1 50 ioqq 1200 800 11 30 60 JOO 13 00 15D0 630 13 35 I 00 250 16(10 1600 1000 20 45 I 25 3 00 3OO0 20 TO MULTI TURN TRIM POTS 50 0*14 iTOQhtu 1000 OMtt 6K lOK POSTAGF- RATES ADD W% FOR ORDERS UWDER «5,00 ADO $% FOR ORDERS BETWEEN 525. 00 AND (50.00 ADD 3% FOR ORDERS ASOYE 550 CO TERMS. FOB CAMBRIDGE. MASS SENG CH.E.£n: (JH Mfi-Mt V DR MINIMUM TELEPHONE. C a D PURCHASE ORDER DR ChaAGE MINIMUM MAIL ORD6H J5 00 nER (20TO SOLID STATE SALES P.O. BOX 74D - SOMERVILLE, MASS. 02143 TEL (617) 547-7053 FAX 617-3S4-141T TOLL FREE 1.800-343-5230 FOR ORDERS ONLY 5 E NO. S 25 F OR DUR CAT* LOG r 1*1 Ltfl I kG TflANStfiTOftSA RECTlflEFtS 145 HAMPSHIRE ST , CAMBRIDCE, M A5S 03135 WE SHIP OVER 95% OF OUR ORDERS WITHIN 24 HOURS OF RECEIPT CIRCLE 74 ON FREE INFORMATION CARD mm-KEYi n -800-344-4539 CORPORA T I O N AK r Putu-to Klco - JUMI1-6fT4 Town* - &21J7S14 FAX - ?1JJ -«t-33M TWX - 9103S08W2 DJGI HEY CORP B NAFlUNALbtMlLaNUUCTCR* PANASON .fK'W nr P i/ , n M ut^i 11 nnAM irniir ir-jnii d-on ncjn MODES* DIAMOND TOOL* UNGAR* iTSF"! oKMACMiwe-Ewc.i^c r »iNTEflsiL*AD / ,^V 256K (262,144 x 1) DRAM 150NS $5,70 M; $39,95/9 es*cwindustr]esVa.mdek«g£. — L > .■■■'■■■VMi:;- ATLANTIC SEWICQWDUC *W^ fpCtOty FtfStS SCCHtMECALS • ARIES • PLESSEY Ipwiaul Tit . ft— p «mt» -JUKT j -^-J M . —' :>™"v •= ) il il J '1 12 6 *if **W . . 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CIRCLE 82 ON FREE INFORMATION CARD > C o c CO (D 00 -4 87 NEC V2Q & V3Q CHIPS Replace the 8086 or 80GB in Your ISM -PC and Increase Its Speed by up to 40% t Part Ho. Prle* UPD70108-5 (SMHi) V20 Chip $ 9,95 UPD70108-8 (SMHi) V20 Chip $11.95 UPO70116-8 (8MHi) V30 Chip S14.95 UPD701 16-10 (10MHi) V30 Chip $34.95 7400 Pari Ho. 1-9 10. Part No. 1-9 10+ 7400. . . ... 29 .19 7485. . . . . . 65 .55 7402. . . . . . . 29 19 7486. .... . . .45 .35 7404. . . .. . .35 25 7489 . . . 2.05 1SS 7405, .... . . .39 29 7490. .49 39 7106 . . ... .39 29 7493. ... j*5 35 7407 ... 39 29 74121. . . ... .45 .35 7108, . . ... .35 25 74123 ... .59 ,49 7410. .... . . . 35 25 74125. . . . ... £5 .45 7414, , . , . .. A3 39 74125 . . . ... .75 .65 741 6. . . . ... .45 35 74143. . , . , . 4.05 3.95 7417. . . . . . .. .45 35 74150. . . . ... 1.35 125 7420. ...as 25 74154. . . . . . . US 125 7430. , . . ... 35 25 74158, . . . . . , 159 1.49 7432, ...35 29 74173. . . ... .55 .75 7438. . . . ... 39 23 74174 ... .65 .55 7442. . . . ... 55 .45 74175. . . . .. . .B5 .55 7445. . , . ... .79 £9 74176 . . , 99 59 7446 ... B9 .79 74151. . . . . . 1.95 185 7447 . . ,BS .79 74159. .. . . . 2135 1.95 7448 . .2 05 1.95 74193 . . ... .79 .69 7472. ... .75 .55 74198. . . .1.85 1.75 7473 ... .45 35 74221. . ... 39 39 7474. ... .45 35 74273 . . 2 05 195 7475. . . ... .49 39 74355 . . ... 59 .59 7475. ... .45 35 74367 . . ... 69 59 y*»i-S 74LSOO .. 74LS02. . , 74LS04. . . 74LS05. 74LS06. .. 74LS07. . . 74LSOS-. . 74LS10. .. 74LS14. , . 74LS27 74LS30. . . 74LS32. . , 74LS42 . 74LS47. . . 74LS73 . 74LS74. . . 74LS75 . . 74LS76. . . 74LS85. . 74LSB6 . . 74LS90. . . 74LS93. . 74LS123. . 74LS125 . '4LSI3S 74LS1 39. . 74LS1S4. 74LS1 57. . 74LS155. . 74LS163. . 74LS164.. 35 . 1.09 1.09 . 29 . 29 . .49 . .35 . 29 . 35 . .49 . .99 39 59 35 .49 .49 . 1.09 .45 74LS165 74US166. . 74LS173. . 74LS174. . 74LS175. , 74LS1 59. . 74LS191,. 74LS193. 74LS221 74LS240. 74LS243. . 74LS244. . 74LS245, 74LS259. . 74LS273 74LS279. . 74LS322. 74LS366 74LS367. , 74LS358. . 74L5373. . 74LS374. . 74LS393. . 74LS59C 74LS624. . 74LS629. 74LS640. 74LSS45 . 74LS670 74LS6SS . .49 . .49 .4.59 . 59 , .79 .55 69 49 3S 39 4.49 .49 .69 . .79 . ,79 . .79 . .89 , .99 . .69 . .49 4.05 . .49 .49 .49 .49 . .79 ,79 69 ,6.05 .2.05 2.29 . 1.09 . 1.09 109 2.05 .79 .59 79 39 3.95 39 39 39 .79 595 1.95 2,19 .99 .99 .99 1.95 740S/PROIWS* 74SOO , , .. 29 74S1BS" . 129 74S04 35 74S189 1.69 74S10. 29 74S240 1.49 74S32. . 35 745244. 1.49 74S74, . . . . . .45 74S253 79 74SB5. . .... ... 1.79 74S267-. . . 1.49 74S86. . . 35 1 .49 74S124 ...2.95 745373, 1>*9 745374, 745175 . . 79 74S472* , 295 74F 74F04. ,39 74F15T. . .... 55 74FO& .39 74F193 3.95 74F10. . 39 74F32. .39 74F244 139 74F74. 49 74F253. .99 74F8S. .59 74F373 139 74F13B. . . .eg 74F374 . . V39 CD— CMOS CD4001 . .19 CD4076. .56 CD4008 .89 CO4081 25 CD4Q11 19 25 CD4013 . ... 29 CD4093 35 CD4016 .... 29 CO4094. 69 CO4017 55 CO40103 2.49 CD4016 59 CO401 07 .69 CD4O20. 59 CD40T09. 1 49 CQ4024. .., .49 r*t CO4027. 35 CD4511 f» C04030. 29 lT04K?n .75 CO4040. ... 65 CD4522. 79 . 29 . ... 29 CO4050-- C04541 .69 CO4051 . .. 58 CD4543., 79 CO4052 59 C04563 4.95 CD40S3. ... .59 CD4555 .79 CD4059 3.95 CD4566 7 49 CD4063. . .. 135 C04S72 |MC 14572J 39 CD40&5. . . . 29 CD4S83 B9 CD4069. 25 CD45B4. 39 CD4070 25 CC4585 H9 CD4071. . . . 2E MCI 441 IP. im CD4Q72 25 MC14490F 1 4.49 COMMODORE CHIPS 1NO. Pric* Part No. WWTODskCgn! «Mi 14.9S 51-3052P SV ftrWiw WBgs fUc !*--., - 595 6502 MM w.liu. Clack . . . 2.25 G504ACPJ. 1.95 6507 ON 445 3.49 6510 CFU 9UW 6520 PIA, 1,75 GS2ZVU 2.95 6525 TPI *-» 4.95 652BC1A.. , ..14.95 6529 SB 445 2.95 S532 126.4MM. I'D. Tin to 6.49 S545-1Cfm: 2.49 Pnc* Part HO. 6551 ACI*. 321 S5S0 VK -l 10.95 . 14.95 510,95 .10,95 .1455 . 14.95 6557 WC-ll 656» vie mm 6572Vk:PM,N. 6551 S0II2V), 6562 513 tfSVJ.. 6360 1>«l EamnB. .10.95 8501 MPUl 1055 6502 WU . . Hi 555 9593 Ml Cow . 1555 6564 VIC.. .454512.95 6S66V1C «L IMS 15.95 6701 PGck OliB . . . 9.95 ■6721 Put. U5S Prtc« S722 MWJ 955 '251 1044)4 Kcms ROM 1055 3U016413aiKB0M-C138...1S55 316019413 Buk BOM-CIS! ... 15.95 31 B020-04 femil ROM -C1 2B. . . 1 5.9 5 325302^)1 64H RBI to 1540'I511 Dfnt. 15.95 -325572.01 Lew *"W. 24 95 "5ZS100PLA !S»3UQir L . . . . 1355 901225-01 Chac ROM. 1155 901 2IW1 BASIC BOM. t1.95 9OIS27-0J«mim)M. 11.95 901229-05 ItKiKt ROM for I54I >a DlMI 1 5 95 'No specs available "Not&:82S100Pm= U17 LC-841 MICROPROCESSOR COMPONENTS MISCEUANfUUS CHIPS Part No. Prieo D765AC. . WD1 770 ,. . 4.49 I'J.OO 14.95 WD9216 935 6.95 no, Z30A. I90B semes Z80 125 ZBO-DART. . Z80-PI0. . . 4 95 1.79 Z80A-CTC. ZSOA-DAFIT ZB0A-P1O zsOA-siora. 1.49 4 95 1 .49 495 ZSOe-CTC 3,49 2BOB-PI0. 429 8500/ 6600' 68000 SER 55C02 (CMOS! . . 6.95 5520 1.75 6800 6802 6610 ...... 1.75 149 125 G50D/GS0G/6BD0G Cant. Part No. PtK* 6840. . ,. . 3.9S 6B43 . . . 2.95 6950 1.49 6652 9i95 2.49 6675 ,.895 MO6SO00L8, . ... 11.95 t«&flOOOLlO 19S5 1495 803, BOliO SERIES zg6 80C3 1 BH . . . 44r95 10.95 8095, . .... 1.49 8073 . . 2995 8080A, . . . 249 808SA. .... 229 8066 ... 695 80B6-2. ... 895 60a7t5MHz).. ..125.00 8087-2(8MHzJ . . 1 59.95 8088 .... 6.49 &cee-2 ., 3.95 8116 ... 4.95 81 55. , . . . 1.95 61 55-2, .... 2.49 8202 .... 9.95 8203. . . 14.95 8212. .. .. 1.49 8224. . .... 225 SDOO SERIES Cant. Pert No. Pile* 8228 249 5237-5 435 . 2.25 . 5.49 .595 . 1.75 1.95 .495 . 1.69 .2-49 8243. . 8250A S2S0B (For ISMI . 82S1A. 8253-5 8254. 6255A-5 8257-5. 8259-5 8272 4.49 6279-5 2.95 8741 10.95 674SD (25V) 9J95 S746H|HMOSJ!2WI..10.9S B749. 9.95 8751 39.95 8755 , 14.95 DAT* AC OH is III ON ADC0804LCN 319 ADC0808CCN 5-95 ADCOB09CCN 3.95 ADC081 SCCN .... 1 4.9S ADCO81 7CCN 895 QAC0306LCN 1.95 DAC1 005LCN. 549 AY-3-1 01 5D 4.95 AY-5-101 3 A . . &95 2.95 Part No. Function ' DTMAM1C RAMS ■ 411S-15 412S-20 (Piggyback) 4164-120 4164-150 4164-200 TMS4416-12 S1 18 41256-120 41256-150 50464-15 51 1000P-10 S14256P-10 15.384 X 1 131A72 X 1 65536x1 65536 X 1 65536X 1 16384x4 16364 x 1 262.144x1 262.144x1 65,536x4 t, 048576 x 1 262.144x4 2016-12 2102-2L 2114N 2114N-2 2114N-2L 21C14 2149 5101 61 16LP.2 6116P3 6116LP^3 6264LP-12 S264H1S 6264LP-15 6514 43256-1 5L 2048x8 1024 X 1 1024 X 4 1024X4 1024X4 1024 X 4 1024x4 256x4 2046x8 2046x8 2046x8 6192x6 6192x8 8192 x 8 1024X4 32.768 X 8 (150ns) B9 (200ns) +49 325 (1 20ns) 1.75 (150ns) 1.15 (200ns) 96 (I20nsl +es 375 (120ns) 69 (120ns), 395 (1S0nS) USS 2 75 (ISOns) (4464) 141464) 4.95 (100ns) 1 Mea 9»95 27.95 (lOOns) 1 Meg. 4+95 29.95 1120ns). 169 (250ns) Lou Ptmer (91L02) 1.95 (450ns) S3 (200nfi) 1.03 (2O0ns) Low Power. 1.49 (200ns) (CMOS) 49 (45ns) +95 3.49 (450ns) CMOS. IBS (120ns) Low Ftower CMOS 235 (150ns) CMOS..... 1.88 (150ns) Low Fewer. 135 (120ns) Low Power CMOS. 425 (150ns) CMOS 359 (1 50ns) Low Power CMOS- 375 (350ns) CMOS (LTPD444C) +49 3.95 (1 50ns) Low Powsr. 2+95 1 7.95 1702A TMS2S16 TMS2532 TMS2564 270S TMS2718 2718 2716-1 27C18 2732 2732A-20 2732A-2S 2732A-4S 27C32 2764-20 2764-25 2764A-25 2764-45 27C64 27C64-1S 27128-20 27128-25 27128A-25 27C 128-25 27256-20 27256-25 27C256-25 27512-25 68764 68766 74S387 74S47I N82S123 256x6 2046x8 4096x8 8192 X a 1024x8 2048x8 2048 X 8 2048x8 2048x8 4096x6 4096x8 4096x8 4096x8 4096 x a 6192x8 £192 xB 8192x8 8192x8 8192x8 B192xS 16384x8 16384x8 16364x6 16364x8 32.768 x 6 32.768 x B 32.766 X B 55.536 x 6 8192x8 8192x8 256x4 256x8 32x6 - PROHS EPBOMS - (1)ffl) .595 (450ns) 25V. 4.B5 (450ns) 25V. 5i95 6.95 (450ns) 25V. BJ95 C450ns) 436 (450ns) 3 ^snaas. 9.95 (450ns). 375 (350ns) 25V 4.95 (450ns) 25V (CMOS). 649 (450ns) 335 (200ns) 21V. 425 (250ns) 21V. 3.95 (450ns) 21V. 3.75 (450ns) 25V (CMOS) 649 (200ns) 21V, 425 (250ns) 21 V. , , 3.78 [250ns) 12.5V. . . , , 425 (450na) 21V 3.49 (450ns) 21V (CMOS) 549 (150ns) 21V (CMOS) 649 (ZOOns) 1 2SK 21V. 5,95 (250ns) 128K21V. 525 (250ns) 1 25V 435 (2S0ns) 21 V (CMOS) 535 (200ns) 256K (125V) 635 (250ns) 256K (125V). . 595 (250ns) 256K (CMOS) (125V) 695 (250ns) 51 2K (1 25V) 19.95 (450ns) 25V. 15,95 (350ns) 25V 1695 PROM O.C 129 PP.OM TS. 4.95 PFtOM TS. 2.49 SATELLITE TV PESCRAMBLER CHIP Trie MM5321 t5 TV camerij sync generolor ricjigri(H^ Ep supply Ihe basic s.ync functions (or titf.tr color or mono- CHfomeE25 hnc/GCHi in'lcrljcccl and cd-ti a ra vnk-? recorder aprjlKcatlons. COLOfl BURST GATE A SYNC allow stable: color Operation MM5321N $11.95 INTERSIL Also Available! 74HC HI-SPEED CMOS PaH No P"C* 25 PirtNo. Price 74HO0& 74HC175 69 74HC02 .25 74HC221 39 74HC04 29 74HC240. . . .79 74HC08. ,29 74HC244 . . .79 74HC10. 29 74HC245 . . . 69 74MC1 A. 49 74HC253 - , 59 74HC30. 29 74HC259 , . . . .85 74HC32 29 74HC273 . . .79 74MC74. 39 74HC373, , .79 39 74HC374. . . 79 74HC7& .45 74HC393, . . 75 74HCS5 .79 74HC595. . . , 1.19 74HC6& 39 74HC638. . . .79 74HC123 .89 74HC4040, . . 39 .49 74HC132 ,49 74HC4050 . sa 74HC133, 49 .49 74HO406O. . . 1 .09 74HC139. 1 .29 741-IC154 1.19 74HC4514. . . 1.19 74HC163. G5 74HC4536 . . . . .69 7JHC174. 69 74HC4543. . 1.19 74HCT — CI TTL 7 :.<■<: ■:.::' 29 -JHC^'39 59 74HCT02 29 74HGT157. 69 74HCT04 29 74KCT174 89 74HCTDB 29 '4HCT175. .69 74HCT10 29 74HCT240- . . 99 74HCT32 . 29 J4HCT244.. . .99 74HCT74 .49 74HCTE45 1.19 74HCT86 49 74H0T373. .119 74HCT13S. . . . . .69 74HCT374. . 1,19 7 4 C — CMOS 74CO0. . . 29 74C1 74. . . .79 74C02. 29 74C175 . ... .79 74O04 29 74C221 ..... 1.49 74COS. 38 74C240 129 74C10 35 74C244 129 74C14 .49 74C373 1.49 74C32 35 74C374 1.49 74C74. 59 74C912 735 74C8R 139 74C915. 139 74C86 35 74C920. 935 74CS9 5.19 74C921 9.95 74C90 -99 74C922. 395 74C1 54. . . 235 74C923. 335 74C1 73 1.05 74C925. . . . 5.95 LINEAR DS0026CN 1 95 LM 1 «E8N 39 TL.034CN. . .99 DS1 4C83N (CMOS) 1.19 LM307M. 45 DS14C89NICMOS) 1.19 LM309K. 1 J5 LM1496N .85 LM311N . .45 MC164BP. 491 LM317T. . ,79 LM1871N 2.95 LM318N . .99 LM1672N 2.95 LM319M..., . 39 LM1896N-1 1.59 LM323K. .3.95 ULN2003A .99 LM324M . .39 XR2205 3.95 LM33BK. .4 95 XR2211 ?«* LM339N . 39 XR2243. 195 LF347N . 1.79 DS26LS29CN 4,49 LM348N .69 DS25LS31CN. 1 19 LM35OT. .2.95 DS26LS32CN 1 19 LF351N . 39 □S26LS33CN 1 cp, LF353N. 49 LM2901 N .49 LF355N . .79 LM2907M Z49 LF356N . .79 LM2917N (8 plnl. 155 LF357N. . 1 09 MC3419CL. H95 LM358M. . .49 MC3446N 238 LM3S0M .2.19 MC3450P. ?9S LM361N. . 1.79 MC3470P. 1.96 LM380N-8. 99 MC3471P 4<P> LM38BN-3. . 39 MC3479P. - 4.79 LM387M . .99 MC34S6P. . 1j69 LM393N . 39 MC3437P. 1.69 LM399H .2.95 LM3900N 49 LF411CN LM3905P* 1.19 TL497ACK .2,69 LM3909N ■» NE540H (C540H) . ME555V XR-L555 LM556K. ME5SBM LM555N. ..2.95 29 .75 .49 69 . . .99 LM3914M. LM3916M NE5532 NES534 7805K (LM340K-5) . 7812K (LM340K-12) 1.95 1.95 .59 .69 . 129 .129 781SK (LM340K-151 129 NE592N- . 39 7805T (LM340T-5) . 49 7812T(LM340T.12J . .49 7815T(LM340T-15! 49 - 59 7905K (LM32DK-5I 1 ftfl MC1350, . 1.49 7905T (LM32QT-5) . 59 MC1372P. .2.49 75472. 39 MC1377P, 319 LM1414N. MC145406P. 2.95 IC SOCKETS Law Pro fife SpriLR 11 14 pin LP. 12 16 pin LP. 13 24 pin LP, .25 2B pin LP. 27 40 pin UP- 59 SoMHUH£l*M*nl [Geld *THl| i Win Wrap (Guidi ■.***! *3 S pn WW. . 59 14 pin WW. £5 16 pin WW.. .68 24 pin WW. 1.19 28 pin WW 159 40pin WW. 1.H9 PARTIAL LISTING • OVER 4000 COMPONENTS AND ACCESSORIES IN STOCK! • CALL FOR QUANTITY DISCOUNTS CIRCLE 114 ON FREE INFORMATION CARD Worldwide • Since 1974 • QUALITY COMPONENTS • COMPETITIVE PRICING 13:WM*M=tWJ=i:r4 ■ Mi it Order El »etfontcs ■ World wi'jo HBEaS ELECTRONICS COMMODORE COMPATIBLE ACCESSORIES HESWARE 300 Baud Modem FOR VIC-20 AND C-64 Connects directly to User Port - Manual Answer/ >ial ■ Function keys defined for convenience ' Includes Midwest Micro Associates communi- cation software. SM-1 IForUIC-id.niiC-et) $8*795 $19.95 External Power Supplies ~PS-1 (r.. c-s4j: $39.95 3PS-1 28 (f« c-1281 $59,95 RS232 Interface Allows connection of standard serial devices. JE232CM (Ftorvic-M„c-64*c-i2aj . . $39.95 "Opflranon wilh "he C-1 2-8 in S4 mode only l-RS-80/TANDY COMPATIBLE ACCESSORIES E-X-P-A-N-D TRS-80 MEMORY Alt kits come complete with documentation TRS-30 MODEL 4, 4P, &4D 64K/12BK EXPANSION TBS-64K-2 57.95 expands Model t from 1 6K-6JK or Model 4 tGatc Array Atrsion). 4P and 4D From 64K-12IK rFtS-64K-2FWL , 91*95 S13.9S =xoands Modal 4 (Non-Gate Array version] rrom 64K1o 12flK rBS-80 MODEL 100 8K EXRUISIDH M1008K MftW 517.95 ZUCKI=RI3C^RD I, SflDBi TANDY 1000 Expansion Memory Half Card Expand the memory ol your Tandy 1000 (12SK Version) to as much as S40K. Also includes DMA comrolter chip. TAN-EM256K Includes 256K RAM $ 99.95 TAN-EM512K Includes 51 2K RAM $1 19.95 TAN-C Pfug-inCfock option cnip (only) $39.95 NEW.' 20Meg Hard Disk NEW! T20MB 20MB Han.: Disk Drive Board for Tandy 1 000. . 957 9 . 9 5 $494.95 SX20MB 20 M8 Hard Disk Drive Board for Tandy 1CCCSX 6509. 9 5 5499.95 TANDY 1000 Multifunction Board with Clock Calendar Expand the memory on your Tondy 1 000 ( 1 28K version) to a s much as 640K. Complete win an RS232 port. clock/calendar. HAM Disk Prinlef Spooter andon-Ooard DMA controller chip. MTAN-256K Includes 256K FIAM. $1 79.95 MTAN-512K Includes 512KHAM $199.95 NEW! Multifunction NEW! Board for TANDY 1000SX M256K includes 256k ram $1 89-95 UV-EPROM ERASER Erases sll EpflOMs. Erases up to 8 chips within 21 mlnules (1 etiip in 1 5 minuure) . Maintains constant exposure distance ol t u . Special conductive loam liner eliminates static build-up. Built-in safety fock to prevent UV exposure. Compact - 9.001. x 3.70'W x 2 fi'O'H. Complete with holdino tray for 8 chips DE-4 UV-EPROM Eraser. . . . $69.95 UVS-11EL Replacement Bulb. ... $19.95 NCF-2 Cond.Foam12x24x<JiHardBlk. S 8,95 HOW YOU CAN BUILD AN IBM PC/XT COMPATIBLE! Jameco's IBM PC/XT Compatible Kit 4164-150 1 2£K RAM ( 1 a Ch Ips) $20.70 IBM-FCC nappy Csnlrallw Card . . $34.95 IBM-Case n.p- Top case $34.95 J-JE1 015 XT.-'AT Style Keyboard . - - $59-95 lr ""» 150 Watt Powar Supply.. S69.95 MonorGrapti, Crd. w/RPort S69.9 5 51V DSDD Disk Drive $99.95 12' Mono. Green Monitor $99.95 XT Motherboard CZero-K f:. .'.' ■■■-. DTK/ERSO 6fDS ROM) $99 95 FREE! QUICKSOFT PC WRITE WORD PROCESSING SOFTWARE INCLUDED! Weight: 48 lbs. Regular List $590.30 JE1004 (Includes 9 items above) . . . . . $499.95 ADDITIONAL ADD-ONS AVAILABLE! RS232HC RS232 Serial Half Card $ 29.95 EM-100 6 x 1 1 a n « i 01 1 M !> mo r v H .1 If Ca r rl ( Wl tlr lit R AM) , , S 59.95 JE1052 Integrated Color Graphics Board $ 59.95 JE1078 Multifunction 0-384K RAM (without RAM) $ 89.95 PM1200B-2 I200/300 <!l:iii -,1H,.ir( :.it:l I.'.-- ■!■ m Wl !li ■■■ .ftwHO, . . $119.95 PM1200B-2S 1200/300 Baud Harf Curd Modem with Mirror Software. . S149.95 JE1 055 Enhanced Graphics 25EK Video RAM $1 99.95 TTX-1410 14 » RGB Color Monitor $289.95 ST225K 20MB Hard Disk Drive, Controller S Cable $339.95 fiUisi reoisrerep trademark of !8M Computers NEW.' Logitech Mice $4££y IBM PC/XT Compatible C7BA5E C7 Mouse wrth 3.1 Software SB 4.9 5 C7PLUS C7 Mouse wrPLUS Pko, SoKwaie $94.95 C7BUS C7 Mpuae wrBua Brd. ft PIUS Ptqj . Sfwr. $109.95 IBM PC/XT/AT Compatible Keyboard n** , F tyte l* Lavot a Layout ■ Tactile touch keyswitches ■- AT style layout ■ Switch selectable between PC/XT or AT ■ Illuminated Caps Lock. Num Lock and Scroll Lock indicators ■ Low profile design ■ S 1 ^ loot cord - Manual included ■ Size: 1S"L x 7VW x IVaTH JE1015 $59.95 IBM PC/XT Compatible Enhanced Keyboard f r I I U;,* iJt.t n f 1 sufcfci scorn .. it: i i.Mi *•- i 111. I I L—-I ' \ vu •Enhanced PC/XT keyboard (equiv. to Keylronics 1 * 5151) ■ Separate cursor and numeric keyboard ■ Typewriter style: layout makes it easier |g learn! ■ LEO indicators ■ Manual included ■ Color: off-white * Size: 20"L x BVYV x 1 VH JE1016 $79.95 Turbo 4.77/8MHz Motherboard IBM PC/XT Compatible •75% faster than the IBM PC while in the turbo mode ■ Turbo Mode selectable through either software or hardware • Expandable to 640K (comes w/zero-K) • DTK/ERSO BIOS included TURBO SALE! $120.05 $119.95 APPLE COMPATIBLE ACCESSORIES Parallel Printer Card ■aj".3Ti?ir.a for Apple II, IH- and lie ■ Intelligent interlace to moat dot matrix graphics printers ■ Centronics standard - Advanced text printing Parallel printer Card $49.95 54K Buffer for JE880 $0 9 . 9 5 $49.95 JE8B03 jEasoeno-jeaaa $9935 $89.95 Extended 80-Column JE880 JE883 Card for Apple We • ao Csl.'G4K BAM ■ Doubles amount ol data your Appro tie can display as well as its mem- ory capacity ■ Ideal for word processing ■ Complete with instructions JE864 $59.95 Additional Apple Compatible Products Available Iameco ldtJ.l.:r.rtM.-i JE310 Fiber Optics Experimenter Kit JUrcu/t/ ' Educational device iWWI rjjvea '■: i. :■'.■■-■. and engtirtGera hands-orr experience with fiber optic technology 9 Step by &tep In- slruclL-una ■ Includes transmitted A racaiver cir-cuits mjards, as, well as el| nee. iC'a, CJlbEas 3 curr. u-iau -i JE31 Fb*r Optic Kit. $1 9.95 am&CA JE450 Sotderless B i "j!5fiai Proto-Type Builder ■ Provides user wilh quick and efficient system for bread boarding electronic circuits ■ Components & wire leads can be quickly inserted and removed without soldering or de- soldering ■ 3 regulated power supplies: 5V @ 1 A, -t-5Vto +15V& .5A, -SV to -15V @ 5A -Power: 1 20VAC, 60Hz (used J new-' JE450 Solrfertess Proto- type Builder . , - S 1 1 9.95 5" /S4 IBM 9 Compatible! DISK DRIVES trtotudmi FD55B HhW ds i 4 -h fjBM pc/xt) . .. $109.95 JU-455 Pina5OTic5^DS^-H([BHPC/XT) $109,95 JU-475 Psnasonic s^ 1 os tt-H (IBM AT) . . $1 29.95 DATA BOOKS '30003 NaEicnal Linear data Book \82} $14.95 30009 Ink-nil Data Book (SG.I » . $ 9-95 30013 ZJlog Data Book (AS} S14.9S 30032 NatiunaE Linear Suppl*menl[84) £ €,95 210830 Intel Memory Handbook (87) S17-95 230343 Intel Microsystem Hndbk. Sel (ST) $24,95 MUFFIN/SPRITE-STYLE FANS MUF60 S9.9S Torin Industries (4.6fl" sq.. 60 ctm] SU2A1 58.95 EG10 flotron 13.155" square. 20 cfm| $20 Minimum Order - U.S. Funds Only Shipping: Add 5% plus S1 .50 Insurance Send $1.00 Postage for a FREE Seasonal Flyer FAX 415-592-2503 8/87 California Residents: Add 6%, 6 1 / 2 % or 7% Sales Tax We reserve the right to substitute manufacturers. ® Mall Order EJGcl rflniCS ■ Worldwide ameco ELECTRONICS VISA* Data Sheets - 50c each Prices Subject to Change Send $1.00 Postage for a FREE 1987 CATALOG Telex: 176043 019S7 Jameeo Electronics 1355 SHOREWAY RD., BELMONT, CA 94002 • FOR ORDERS ONLY 415-592-8097 • ALL OTHER INQUIRIES 415-592-8121 CIRCLE 1 14 ON FREE INFORMATION CARD r Computer Power Command Center for only $39.95! At this price they won't last long, so order yours today! v This superb monitor stand puts control of your entire system at your fingertips! Our special purchase of these units can put one in your hands at an unbeatable price! TILT & SWIVEL POWER COMMAND *39 95 X-1128 Get rid of that confusing maze of wires and ease operator fatigue with this one fantastic product! The monitor stand swivels 360° and tilts 12.5° to improve line of sight and minimize glare. The electronics built into the base provide EMI filtering and surge & spike protection for five component inputs. You can plug your computer, monitor, printer, and two other devices into the 3-pin sockets in the back of the stand and control them individually with the lighted rocker switches on the front Or rum the entire system on and off with the master control switch! SIZE: 11 WW x tQWD i3K"H WEIGHT: 4 lbs. POWER CORD: 54" 1 4 AWG > 3C CIRCUIT BREAKER: 1 5 Amp Compare Our Price! Dealer Inquiries welcome! Just circle reader service number 189 o DC o UJ o 5 < 20 MHz Dual Trace Scope Price Breakthrough! was $399 - SAVE $80 now Includes quality probes (xl,xl0,gnd) Built-in component tester TV- video sync (liter X - Y operation Z-axis (intensity modulation) 1 yeat wartanty $319' SPECIFICATIONS 15 MHz PORTABLE DUAL TRACE 20 MHz DUAL TRACE 35 MHz DUAL TRACE SO MHz DUAL TRACE Rise lime | usee} 24 <17.S <10 <7.7 Mix input 600 V p-p or 300V | DC ± peek AC] Input Impedance 1 M ohms shunted by 20pF ± 3pF for all models Chop frequency 200 KHz (appro*] for all models Channel separation eotse 6 i khi 60dBO 1 KH; 60dB @ IKHi 70dB @> 1 KKi Time base .5 usee ■ .5sec .2 usee to .5 sec .1 usee -. 5 sec 2 usee - .5 sec CRT 95 mm 5" 5" 5" Cat No, 0-1 Z44 0-1240 Q-1241 0-1243 Versatile prob* suits virtual lv any'scope. It features built « al/xlO switch. 4' of SHIELDED cable with FJNC connector, and wandering earth lead with alligator clip, insulting, shroud. Spscrtlcotiorij Working voltage - &G0V FA {or 600V 0Q# Bandwidth - xl: DC-10MHi/ztO: DC-l0OMHi« input r^sslonce -*1 IMohnv'xTO: 10M ohm • Input capacitance -xl : 40pF ±CKQ input e/xlO: 10- 60pF • HEF position -probe groundad wta 9M resistor. NOW SAVINGS $349 $150 $3t9 $80 $449 $150 $649 $250 All "scopes are supplied with schematics 90 14-Day Satisfaction Guarantee MAIL ORDERS DSE, P.O. BOX 8021, Redwood City, CA 94063 We ship UPS Ground unless otherwise requested Add 5% of order total j-mm S1.50I for shipping Outside USA add 20% (mm $4) Thete 15 an additional Si 50 handlmg fee California residents please add sales tan VISA and MASTERCARD welcome. Minimum order value $20,00 PttMt* Not*; Stfe flflttt *rt MfmifMbft by MAIL ORDER ONLY. You musi irjru rion this »d mnd quote Ihe pricwl On Him ttwmj you wttt, otfmr vmiid through July 3 J. 1*87 or whjlt mttpptfct last ■ qutnUlims art ftmitad, so hurry? ELECTRONICS Stores m Hf RK£ tf V. CA 14 1 5/ 4BS-0 755. flf 0W00D CITY. CA I* IS) 368-88*4. SAN JOSE CA 14081 2* 1-2266 To receive your copy of our Colorful 148 page catalog, circle Reader Service 130 Order by Phone 41 5-368-1 066 Mon - Fri 7am - 6pm Pacific Time Here is just a sample of what you'll find at MCM Electronics Tenma Soldering Station ■ Adjustable temperature range of 150M2u°C (300' 790° F} ■ Grounded tip tor soldering static sensitive devices ■ Overheat protection with closed loop temperature control ■ Replaceable iron clad tip ■ Improved circuit design for greater temperature stability Deluxe Anti-Static Oesoldering Tool ■ Rugged metal construction ■Anti- static lip ■ Nozzle cleaner ■ Lightweight and compact ■ Disassembles easily for cleaning ■ 7¥«" long x %" diameter 1 15MHz Dual Trace Portable Oscilloscope ■ Dual trace model capable of displaying signals up to 15MHz, for up to two hours on a single charge of its internal battery ■ Power can be supplied from either a 12VDC or 120/240V 5O/60HZ AC source Tenma 10 Amp Regulated Power Supply ■ Output: Regulated 13.8VDC ■ Input: 1 2D VAC ■ Fuse protected ■With easily accessible fuse holder ■ Neon light indicator ■ Heavy duty binding posts ■ Effective beat sinks for more power dissipation ■ Output current: 10 amp one minute on. three minutes off; 7 amp continuous Tenma LCR Meter ■ LCR Meter provides a convenient way to accurately measure inductance, capacitance and resistance (.01 ohm resolution) on its 314 digit LCD display For more specs and Test Equipment see pages 146-154 of Catalog #15 Anti-Static Work Mat ■ A must for the modem service shop. ■ Use in conjunction with our #21-660 wrist strap to help eliminate static related problems ■ 18" x 26" Anti-Slatic Wrist Strap ■ This wrist strap when used with our anti-static work mat, will effectively dissipate static charges ■ The five foot coiled, cord with 1Mohm resistor, snaps to wrist strap to give user added mobility ■ Cord is terminated with a banana plug and alligator clip For complete information see page 136 of Catalog #15 Be Sure To Call For Your FREE Catalog! Over 7,000 Items! Call Toll Free 1 -800-543-4330 Additional Soldering Equipment can be found on pages 137 and 138 of Catalog #15 Super Wash ■ Powerful spray cleans intricate electronic assembly without harming plastics ■ Dries instantly ■ Spray literally blasts dirt and grease away ■ 24 oz. Tuner Cleaner ■ Cleans, lubricates, protects ■ Cleans and restores dirty and corroded contacts ■ Doesn't harm plastics ■ 16 oz. Wire Stripper and Cutter ■ Made of tempered steel ■ Adjustment can be sel for wire sizes 10-24 gauge ■ Return spring ■ Cushion grip ■ 5M" long For more Chemicals and Tools see pages 128-136 of Catalog #15 Diskette Pile Box ■ Stores up to 70 — 514" diskettes t Case made of anti-static ABS plastic with smoked acrylic cover ■ Six adjustable index dividers Deluxe Joystick for Atari and Commodore ■ For use with Atari, Commodore and other VCS compatible systems* Two firing buttons cord with 9 pin plug Catalog #15 has other Computer Equipment and Accessories on pages 119-127 SoS © 1987, MCM Electronics MCM ELECTRONICS 858 E. CONGRESS PARK DR. CENTERVILLE, OH 45459 A PREMIER Company > c o c 07 In Ohio 1-800-762-4315 In Alaska and Hawaii 1-800-858-1849 CIRCLE 87 ON FREE INFORMATION CARD SOURCE CODE: RE-35 91 1200B MODEM $9095 «««•■' 2400B MODEM $19995 2101 SI 01 2102 L-4 2112 2114 ::i i.-.i •; 2114L-2 2114L-1S TMS4044-4 TMM2015-150 TMM201S-100 HM6116 : HM61163 HM6116LP-4 HM6116LP-3 HM6116LP-2 HM6264P IS HM62B4LP-1S HMS2B4LP-12 I i 1 L.IW [lov.nr 256x4 256x4 1024x1 258»4 1024x4 1024x4 1024x4 1024.4 4096*1 2043x3 204 S xS 2043x3 2048x8 2048x6 204 a xa 2048.3 8192x6 81 92x8 6192xS I450na) BSOneHCMOS] MStlri-.liUI'i 1450.15! |450na) BSOnaliLPI <200nIKI.PI 1 150..5I 1 1 P! (450ni| 1150ml (100ne| T200nsl[CMO5| [150n«HCMOS| [200ml [CM OS Ml PI l150m)[CMOS)[LP| (1Z0ml(CWOSI[LP) HMnWCMOSi (150n«](CMOS)(LP) (120n»](CMO5)(LP) 1.95 3.95 .93 2.99 .99 1.09 1.49 1.95 1.95 1.49 1.95 1.89 t.95 1.95 2.05 2.95 3.89 3 95 4.49 DYNAMIC RAMS 4116-250 4116-200 411S-150 4116 120 MK4332 J164-200 41 6-1-1 50 41 64-1 20 MCM6665 TMS4164 16384x1 16384x1 16384x1 16384x1 32758,1 05536x1 65536x1 85536x1 66535x1 65535x1 4164- REFRESH 65536x1 5v= Single S Volt Supply 9035 1.49 9039 1.95 6080 2.95 BOSS 2.49 6087-2 169.95 8067 129.00 8038 6.95 80BB-2 9.95 81 5S 2.49 8155 2 3.95 874S 7.95 8755 14.95 80ZS6 129.95 S0Z97 199.95 8200 9203 24.95 9205 3.29 9212 1.49 9216 1.49 9224 2.25 6237 4.95 8237-5 5.49 8250 6.95 9251 1.69 9251 A 1 89 B2S3 1.69 8253-5 1.95 B2SS 1.63 9255-5 1.89 9259 1.95 3259-5 2 2 9272 4.95 9279 2.49 9279-5 2.95 9282 3.95 92S4 2.95 9286 395 19288 4.95 z-ao ZSO-CPU 2BMHje1.69 1 4.0 MHZ ZSOA-CPU 1.79 ZSOA-CTC 1.89 ZBOA-DART 5.95 2SOA-DHA 5.95 ZSOA-PtO 1.89 7.S0A-S1O/0 5.95 ZBOA-SIO/1 5.95 ZBOA-SIO/2 5 95 6.0 MHZ zeoB cpu 3.75 1 Z80B-CTC 425 Z80BPIO 4 25 1 ZSOB DART 14.95 1 2808 S1O/0 12.95 1 2806 SI 2 12.95 1 Z8G71 ZILOQ 19-95 J (250m) |200m) .I50nsl (120ml 1200m) 1200m 1(5 «l (150m 1(5*1 (120ml(5v) (200mll5vj (150m|(Sv) (ISOnallSVHREFHESHI |150ml[5vl IISUiis-.lSvl i1SU.iij.5vi (200m||5v) [15Qns)(Sv| REFHESH.PLn 1 Raff. .99 99 1.49 6.9S 1.19 1.29 1.95 1.95 1.95 2.95 4.95 5.95 6.95 2.95 Z.95 ■■h • **• HIGH-TECH ••••' NEGV20 UP07010B $1195 REPLACES 8080 TO SPEED UP IBM PC 10-40% * HIGH-SPEED ADDRESS CALCULATION IN HARDWARE * PIN COMPATIBLE WITH 8088 * SUPERSET OF 8088 INSTRUCTION SET * LOW POWER CMOS 8MHZ V20 UPD70108-8 $13.95 8MHZ V30 UPD70116-8 $19.95 • ••• SPOTLIGHT • ••• ORDER TOLL FREE 800-538-5000 EPROMS 2708 1024*9 (450ml 4.95 2716 2043x8 (450nj)(5V) 3.49 2716-1 2048x9 (350 nil (5 VI 3.9b TMS2532 4096x8 1450m) |S V) S.95 2732 4096a9 (450n«](5V) 3. 95 2732A 4096x9 (250m)(5VM21VPGM 3.95 2732A-2 4096x9 (200m)(5VII21V PGM 4.25 27C64 81 92x6 (250m)|5V|(CHOSI 5.95 2764 8192x9 (450m) ( 5 V). 3.49 2764.250 81 92x9 (250m](5V) 3.9S 2764-200 8192x9 (200m) ISV) 4.25 MCM68766 8192x9 (350m)(5V)(24 PIN) 17.96 27128 16994x8 (250m)(6«) 4.Z5 27C2S8 32769x3 |250m)l5V)(CHOSI 10.95 27256 3276SxB (2S0m)|5V) 7.49 5V. Single 5 '-'■ .Ir Supply 21V PGM.Progrim M 21 VoftiJ DSPECTRONICS CORPORATION EPROM ERASERS CRT CONTROLLER 8645 4.95 68B4S B.95 6847 11.95 HD 46505 SP 6.95 MCI 372 2.95 8275 26.95 7220 19.95 CRTS027 12.95 CRT5037 9.95 .TMS9918A 19.95 J DISK CONTROLLER 1771 4.95 1791 9.95 1793 9.95 1795 12.95 ! 1797 12.95 2791 19.95 1 2793 19.95 2797 29.95 6843 19.95 8272 4.95 UPD765 4.95 MR8876 12.95 MBBS77 12.95 1 1691 6.95 12143 6.95 8501 1.0MHZ 6502 2 69 65C02ICMOS1 12.95 I 6507 9.95 6520 1.95 6522 4.95 6526 26.95 6532 6-95 654S 6.95 6551 5.95 6561 19.95 6591 34.95 2.0 MHZ 6502A 2.95 B520A 2.95 E522A 5.95 5532A 11.96 6545A 7.95 6551 A E.95 3,0 MHZ L 6502B 6.95 J BIT RATE GENERATORS [ UARTS AY5-1013 3.95 AY3-1015 4.95 TH1602 3.95 2651 4.95 IM64Q2 695 IM6403 9.95 1 INSB250 6.95 J BBOO 1 1.0 MHZ 6900 1.95 6902 4.95 6803 9.95 6809 5. 95 6809E 5.95 MM 1.95 6920 2.95 6921 1 95 6840 6.9S 6843 19.95 6944 12.95 6S45 4.95 6847 11-95 5850 1.95 6883 22.95 2.0 MHZ 6SB00 4.95 6SB02 5.95 68809 E 6.95 6SB09 6.95 68BZ1 3.95 68845 6.95 68BS0 2.95 6SB54 7.9S J SOUND CHIPS 76477 5-95 764B9 a. 9 5 SSI -26 3 39.95 AV38910 12.95 AY3S912 12.95 . SP1000 39.00 , ' CRYSTALS ' . 32.769 KHi .95 1.0 MHz 2.95 1.8432 2.95 2.0 1.95 2.097152 1.95 1 2.4576 1.95 3 2703 1.95 3.S79545 1.95 4.0 1.95 4.032 1.95 5.0 1.95 5.06 BB 1.95 6.0 1-95 6.144 1.95 6.5536 1.95 8.0 1.95 10.0 1.95 10.73B635 1.95 12.0 1.95 14.31618 1.95 1S.0 1.95 ! 18.0 1-95 17.430 1.95 18.0 1.95 18.432 1.95 20.0 1.95 22.1184 1.95 24.0 1.95 32.0 1.95 CRYSTAL OSCILLATORS I I.OMHi 5.95 1.8432 5.95 2.0 5.95 2.4576 5.95 2-5 4.95 4.0 4.95 5.0688 4.95 E.O 4.95 6.144 4.95 8.0 4.95 10.0 4.95 12.0 495 12.480 4.95 15.0 4.95 16 4.95 19.432 4.95 20.0 4.95 .24.0 4 95 J CLOCK CIRCUITS MM5369 1.95 MM5369-EST 1.95 MM58167 12.95 MM 5 a 17-! 11.95 [ MSM5832 2.95 r misc TMS99531 9 95 TMS99532 19.95 ULN2003 .79 3242 7 95 3341 4 95 MC3470 1.95 MC3480 8.95 MC3467 2.95 11C90 19.95 2513-001 up 6.95 AV 5-2376 11.95 l AY5-3600PB0 11.95 Model Timer Capacity Chip Intensity (uW/Cm") Unit Price PE-14 NO 9 8,000 S83.00 PE 141 VES ■ 8.000 *1 19.00 PE-24T YES 12 9. BOO SI75.0O HIGHSPEED CMOS A now family o1 high speed CMOS logic featuring I he speed ol low power Sehottxy [6ns typical gala propagation delay), combined with the advantages of CMOS- vetv law power consumption, superior noise immunity, and imnrcyod output dnve. 74HC: Operate ai CMOS To* new. all-CMOS designi, 74HC00 .S3 74HC02 .59 74HC04 ,59 74HC0S .59 74HC10 .59 74HC14 .79 74HC20 74HC27 74HC30 74HC32 74HC51 74HC74 74HC95 74HC85 74HC93 MHCI07 74HC109 74HC112 74HC125 74HC132 74HC133 74HC138 74HC139 logic levels and are ideal .59 .59 .59 .69 .59 .75 1.35 .69 1.19 74HC14B 74HC151 74HC154 74HC157 74HC15S 74HC163 74HC175 74HC240 74HC244 74HC24S 74HC257 74HC2S9 74HC273 74HC299 74HC36S 74HC373 74HC374 74HC390 74HC393 74HC4017 74HC4020 74HC4049 74HC405O 2.49 .89 .95 1.15 .99 1.B9 1.69 1.89 .85 1.39 1.89 4.99 .99 2.29 2.29 1.39 1.39 1.99 1.39 .89 74JHCT: Direct drop- and can be intermixed vu .69 69 69 69 79 BS .95 1.15 1 16 2.99 in replacements lor LS TTL ith 74 LS in lite same circuit. 74HCT166 74HCT174 74HCT133 74HCT194 74HCT240 74HCT241 74HCT244 74HCT24S 74HCT257 74HCT259 74HCT273 74HCT367 74HCT373 74HCT374 74HCT393 74HCT4017 74HCT4040 74HCT4050 3.05 1.09 1.39 1.19 2.19 2.19 2.19 2.19 .99 1.59 2.09 1.09 2.49 2.49 O o III O < 92 Visit our retail store located at 1256 S. Bascom Ave. in San Jose, (408) 947-8881 nR IX/llOrOrJOV /IPP^ please use your customer number when ordering xevaPLn*'! 1 I V 1'lxV^I \J xLJxa^ If |x«^V^xl^ T ERMS Minimum order S 10 06 Ft* shipping and tundl.no inctuoV 52 59 to* UP5 Ija |* | p. - | /*.* />A riertOft Ground and S3 50 for UPS All Orders ovi-r 1 It) and loretgn olden ntrty n.x»i«. lU l\nOWIeS UriVe, LOS UiatOS, OA BbUOU addieonaihipBmgcharo«ph7J»cc™it^louisafcdv1JarinKwtl w llx-.itlxAnlCA ,li, T»«ll !?_>. on/i coo ennn - /until t>«M~ r-nnn K-«di-nbinusl»relucw..)pp<icatxeiileitai Alinwcnanoii*- rawananhHjlor90d.il> ".'Yf/K-V' IOII Tree OUU-OOtS-aUUU • (4UO) OOO-bidUU "■»*» othunroe >talM Pnc« aic iilhu-cl lo chanca: without noli,..- wi- ji ■a fe^, F . v ;.... n-ro nnn-^ _-ri *^4 -*+r* iwpoitsJsle kn lypuq.jpnicn morv Wi- n-urivc Ihe nqhl to hum r«M»lilm and tu gjiV l"AA (*HJOj Oi'tS-OHZ/ • leleXl71-1lU sutatltuKoianulaclurvr All niorchandls.. subiocl lo pnot Hk." - V^J^V" COPYRIGHT 1987 JDR M1CRODEVICES THE JDR M1CRODEVICES LOOO ISA BEOISrEHED TRADEMARK OF JDR MICRODEVICES JDR INSTRUMENTS AND JDR MICRODSYICES ARE TRADEMARKS Ol JUH Mil RODEVlt f. 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NUMERIC KEYPAD W' CURSOR CONTROL . CAPS LOCK ■ AUTO-REPEAT KEYBDARD-AP $49.95 * REPLACEMENT FORAPPLE II KEYBOARD - CAPS LOCK KEV r AUTO-REPEAT i- ONE KEY ENTRY OF BASIC OR CP/M COMMANDS JOYSTICK cB-io $19.95' . SET X-Y AXIS FOR AUTO CENTEH OR FREE MOVEMENT ■ FIRE BUTTON FOR USE WITH GAME SOFTWARE t ATTRACTIVE. SOLID. PLASTIC CASE • INCLUDES ADAPTOR CABLE FOR IBM. APPLE II, Ik-. II 0, ATARI & VIC 20 61 POWER STRIP $12.95 * UL APPROVED * 15A CIRCUIT BREAKER CASPER EGA MONITOR EGA & CGA COMPATIBLE SCANNING FREQUENCIES: 15.75 / 21.85 KHz RES; 640 a 200 f 3S0 31mm DOT PITCH. 25 MHe 16 COLORS OUT OF 61 14", BLACK MATRIX SCREEN CASPER RSB MONITOR ■ COLOR 'GREEN/AMBER SWITCH ON REAR . DIGITAL RGB-IBM COMPATIBLE • 14" NON-GLARE SCREEN • RESOLUTION; 640 H x 240V ■ 39mm DOT PITCH ■ CABLE FOR IBM PC INCLUDED SAMSUNG MONOCHROME ■ fBM COMPATIBLE TTL INPUT • 12" NON- GLARE AMBER, LOW DISTORTION SCREEN • RESOLUTION: 720H N 350V i ATTRACTIVE CASE WITH SWIVEL BASE • ONE YEAR WARRANTY FORTROHICS MONOCHROME - IBM COMPATIBLE TTL INPUT t 12" NGN-GLARE SCREEN I VERY HIGH RESOLUTION' 1100 LINES |CENTER| ■ 25 MHl BANDWIDTH ' CABLE FOR IBM PC INCLUDED IMBEI OS 8IEEH HYWUBLE $399.95 $299.95 $119.95 $99.95 TILT S SWIVEL MONITOR STAND M2" WITH POWER CENTER *39" APPLE COMPATIBLE INTERFACE CARDS EPROM PROGRAMMER - DUPLICATE OH aURN ANY 27xx SERIES EPROM 12716 TO 271 2B) ■ MENU-DRIVEN SOFTWARE ■ HIGH SPEED WRITE ALGO- RITHM 1GKRIMCIRD * FULL 2 YEAR WARRANTY ■ EXPAND YOUR 48K MACHINE TO A FULL 64K OF MEMORY » CAfr BE USED IN PLACE OF THE APPLE LANGUAGE CARD IC TEST GflRD - QUICKLY TESTS MANV COMMON ECs * DISPLAYS PASS OR FAIL ' TEST 4000 & 74HC SERIES CMOS. 7400. 74LS. ML 74H Si 74S RP-525 55995 RAM-CARD S3995 IC-TESTER S129"J MOLDED INTERFACE CABLES 6 FOOT, IKHt SHIELDED. MEETS FCC C. ITDH RITEMAN II PRINTER >A IBM PARALLEL PRINTER CARLE CENTRONICS IMALE TO FEMALE) CENTRONICS IMALE TO MALE) MOOEM CABLE IFOR IBM) RS232 SERIAL (MALE TO FEMALE! RS232 SERIAL (MALE TO MALE) KEYBOARD EXTENDER [COILED! 1 APPLE II JOYSTICK EXTENDER SWITCH BOXES ALL LINES SWITCHED, GOLD PLATED CONNECTORS. QUAUTY SWITCHES 2 WAY $39.95 • CONNECTS 2 PRINTERS TO 1 COMPUTER OR VICE VERSA IB-? (CENTRONICS PARALLEL) IB-S ff)S232 SERIAL) • 160 CPS DRAFT. 32 CPS NLQ . 9 » 9 DOT MATRIX - SUPPORTS EPSON 'IBM GRAPHICS ■ FRICTION AND PIN FEEDS > VARIABLE LINE SPACING AND PITCH $219.95 IBM ffiWTER CIBLE $9.95 I REPLACEMENT HIBBON CARTRIDGE $7.95 j NASHUA DISKETTES NASHUA DISKETTES WERE JUDGED TO HAVE THE HIGHEST POLISH AND RECORDED AMPLITUDE OF ANr DISKETTES TESTED (COMPARING FLOPff DISKS BTTE B1S4) M-MD2D M-MD2F N-MD2H N-FD1 N-FD2D DS/DD SW SOFT DS.'QLIAD SW SOFT DS/HD SW FOR AT SS'DDH"SOFT OS/ DO S' SOFT S9.90 $19.95 $24.95 SZ7.95 $34.95 3 WAY $99.95 - CONNECTS 3 PRINTERS TO 1 COMPUTER OR VICE VERSA SWITCH -3 P (CENTRONICS PARALLEL) SNITCH-3S (RS232 SERIAL) BULK DISKETTE SALE 5V." SOFT SECTOR, DS/DD W/TYVEC SLEEVES & HUB RINGS $9 9 ° 69C ea 59Cea BOX OF 10 HILKQIY5D BULK 01* 250 DISKETTE FILES 300B MODEM $49.95 SW DISKFILE HOLDS 70 $9.95 IV DISKFILE HOLDS 40 $9.95 FOR APPLE OR IBM INCLUDES ASCII PRO-EZ SOFTWARE . FCC APPROVEO ■ BELL SYSTEMS 103 COMPATIBLE ' INCLUDES AC ADAPTOR ■AUTODIAL ■ DIRECT CONNECT . CABLE FOR APPLE lie 514.95 I SPSeagate 5W HARD DISK DRIVES ST-225 HALF HT 20MB fi5™ &27S ST-238 HALF HT 30MB eSn^HLL) S239 ST-251 HALF HT 40MB 40m* S599 ST- 277 HALF NT G0MB 40rm ,RLL) CAUL ST-4038 F U LL HT 30MB 40rru $553 .ST-409.fi FULL HT BOMB 2fi.ni Si 195 J Vj HEIGHT FLOPPY DISK DRIVES 5Vt" TEAC PD-S5B DS/OD S109.S5 5W TEAC FD-55F DS.QUAO ST24.95 SW'TEAC FD-SSGFVDS.HD S15*.95 5%" MITSUBISHI DS/HD ST29.95 3Vi" TOSHIBA KfT DS DO 5149.95 KIT INCLUDES MOUNTING HARDWARE TO FIT 5W S, FACEPLATES FOR AT I XT DISK DRIVE ACCESSORIES TEAC SPECIFICATION MANUAL S5.M TEAC MAINTENANCE MANUAL £25 0-D W HT MNTG HARDWARE FOR IBM 32.95 MO UN Tl NG fl Al LS FOR ISM AT $4 95 "V" POWER CABLE FOR SW FODs 52.95 SW FDD POWER CONNECTORS M.tS J DISK DRIVE ENCLOSURES WITH POWER SUPPLIES C*B-iSV5 DUAL SLIMLINE BV«" «49»> CHB-1FH5 FULL HT 5V," '69 1! CHB-2SVB DUAL SLIMLINE 8" '209" CaB-JFHB DUAL FULL HT 6" '218" [BUILD STEVE CIARCIA'S INTELLIGENT EPROM PROGRAMMER AS SEEN IN BYTE, OCT. M • STAND-ALONE OR RS-232 SERIAL OPERATION ■ MENU SELECTABLE EPROM TYPES- NO CONFIGURATION JUMPERS • PROGRAMS ALL 5 V 27XXX EPROMS FROM 2716 TO 27512 - READ. COPY OR VERIFY EPROM . UPLOAD /DOWNLOAD INTEL HEX FILES • PROGRAMMER DRIVER USER MODIFIABLE 0NLY$199 KIT INCLUDES PCB AND ALL COMPONENTS EXCEPT CASE & POWER SUPPLY CALL FOR VOLUME QUOTES copyright 1987 jdr micro-devices CIRCLE 182 ON FREE INFORMATION CARD I 94 QUALITY IBM COMPATIBLE MOTHERBOARDS FROM MODULAR CIRCUIT TECHNOLOGY I TURBO 4.77 / 8 MHZ $129.95 JDR PART #: MCT-TURBO * 4.T7 OR S MHjs OPERATION WITH 80BB-2 & OPTIONAL B0S72 CO PROCESSOR * DYNAMICALLY ADJUSTS SPEEO DURING DISKETTE OPERATION FOR MAXIMUM THROUGHPUT AND RELIABILITY * CHOICE OF NORMAL / TURBO MODE OR SOFTWARE SELECT PROCESSOR SPEED | STANDARD 477 MHZ $109.95 JDR PART #: MGT-XTMB * HOB B CPU. OPTIONAL &0B7 CO-PROCESSOR * 3 EXPANSION SLOTS i EXPANDABLE TO 540K ON BOARD Mi.HOBV /OK RAM INSTALLED) i A LL I Ct SOC K ETE D -HI G H EST QU ALI T¥ PC B * ACCEPTS 2764 OR 27t2H ROMS BOTH WITH FREE MCT BIOS! FARADAY FDD CONTROLLER JDR PART »: FAR-FDD ■ SUPPORTS UP T0 1 INTEHNALLY MOUNTED FDO> ■ IBM COMPATIBLE. INTERFACES TO 360K OR 72DK USING DOS 3.20 < INCLUDES CABLE FOR 2 DISK DRIVES IBM COMPATIBLE FLOPPY DISK DRIVE JDRPARTIlFDD-XO GOOD QUALITY DRIVES BY MAJOR MA NUFAC TURERS SUCH AS QUME, TANDON i CDC * 5W r HALF HEIGHT * DS/DD ■ 360K STORAGE CAPACITY * 48 TPI $24.95 $69.95 IBM STYLE COMPUTER CASE AN ATTRACTIVE STEEL CASE WITH A HINGED LID. FITS THE POPULAR PC/XT COMPA TIBLE MOTHERBOARDS BUILD YOUR OWN 256K XT COMPATIBLE SYSTEM ■.1li,i']|.Hil'llM,l'1 ■ SWITCH CUT-OUT ON SIDE FOR PC/XT STYLE POWER SUPPLY ■ CUTOUT FOR 3 EXPANSION SCOTS ■ ALL HARDWARE INCLUDED $34.95 SLIDE TYPE CASE $39.95 SIO995 PRO-BIOS (A $20 VALUE) FREE! 256K RAM $26" 130 WATT POWER SUPPLY *69" FLIP-TOP CASE '34" KEY TRONIC "KEYBOARD '49" 360K DRIVE $69" FARADAY CONTROLLER $24" MONOCHROME ADAPTOR '49" FORTROKICS MONITOR '90" TOTAL: $536.15 IBM COMPATIBLE KEYBOARDS MCT-5150 $59.95 ■ "5150" STYLE KEYBOARD . FULLY IBM COMPATIBLE • LED STATUS INDICATORS FOH CAPS & NUMBER LOCK • LARGE. EASY TO REACH SHIFT & RETURN KEYS . S3 KEY TYPEWRITER LAYOUT OLi i_|_J_U H MCT-5151 $79.95 i~t~t ; i''-'- Y-firr-n . REPLACEMENT FOR KEY THONIC'- KB-5151 KEYBOARD • SEPARATE CURSOR B, NUMERIC KEYPAD • CAPS LOCK & NUMBER LOCK INDICATORS . IMPROVED KEVBOARD LAYOUT MCT-5969 $59.95 ^ ^TTT*! > IBM AT STYLE LAYOUT • SOFTWARE AUTOS ENSE FOH XT OR AT COMPATIBLES ■ EXTRA LARGE SHIFT & RETURN KEYS ■ LED INDICATORS FOR SCROLL, CAPS ft NUMBER LOCK r AUTO REPEAT FEATURE MCT-5339 $99.95 > IBM ENHANCED STYLE LAYOUT 1 SOFTWARE AUTO SENSE FOR XT OR AT COMPATIBLES 1 12 FUNCTION KEVS ■ EXTRA LARGE SHIFT & RETURN KEYS • LED INDICATORS FOR SCROLL. CAPS & NUMBER LOCK i AUTO HEP EAT FEATURE ■ SEPARATE CURSOR PAD EASYDATA MODEMS All models feature auto-diali answer I radial on busy, Hayes compatible, power up self test, toucbtone or pulse dialing, built-in speaker, PC Talk III Communications software. Bell Systems 103 & 2I2A full or half duplex and more. INTERNAL EASYDATA-12H $99.95 1200 BAUD HALF CARD EASYDATA-12B $119.95 1200 BAUD 10" CARD EASYDATA-24B $199.95 2400 BAUD FULL CARD EXTERNAL NO SOFTWARE INCLUDED EASYDATA- 1 2D $119.95 1200 BAUD EASYDATA-24D $219.95 2400 BAUD vxf" ill U*. DISPLAY CARDS FROM MODULAR CIRCUIT TECHNOLOGY MCT-EGA $179.95 KXM IBM COMPATIBLE, PASSES IBM EGA DIAGNOSTICS • COMPATIBLE WITH IBM EGA. COLOR GRAPHICS AND MONOCHROME ADAPTORS ■ TRIPLE SCANNING FREQUENCY FOR DISPLAY ON EGA. STANDARD RGB DR HIGH RES- OLUTION MONOCHROME MONITOR • FULL 25SK OF VIOEO RAM ALLOWS 640 I 350 PIXELS IN 1 6 OF 64 COLORS • LIGHT PEN INTERFACE MCT-CG $49.95 COMPATIBLE WITH IBM COLOR GRAPHICS STANDARD * SHORT SLOT CARD USES VLSI CHIPS TO INSURE RELIABILITY t SUPPOHT5 RGB, COMPOSITE MONOCHROME & COLOR AND AN Rf MODULATOR OUTPUT fc 320 x 200 COLOR GRAPHICS MODE * 640 a 200 MONO GRAPHICS MODE 'LIGHT PEN INTERFACE MCT-MGP affiCv $59.95 COMPA TIBLE WITH IBM MONOCHROME AND HERCULES GRAPHICS STANDARDS « SHORT SLOT CARD USES VLSI CHIPS TO INSURE RELIABILITY i PARALLEL PR! NTE R PORT, CONFIGURABLE AS LPT1 OR LPT2 • 720 x 348 GRAPHICS MODE • LOTUS COMPATIBLE • CAN HUN WITH COLOR GRAPHICS CARD IN THE SAME SYSTEM MCT-MG $79.95 COMPATIBLE WITH IBM MONOCHROME AND HERCULES GRAPHICS STANDARDS • SERIAL PORT OPTION • PARALLEL PRINTER PORT . 720 it 348 GRAPHICS MODE • 80 x 25 TEXT MODE ■ LOTUS COMPATIBLE ■ SELECTABLE TO RUN ALONG WITH COLOR GRAPHICS CARD IN THE SAME SYSTEM MG-SERIftL OPTIONAL SERIAL PORT 'IS 19 MCT-MONO $49.95 ANOTHER FANTASTIC VALUE FROM JDR! IBM COMPATIBLE TTL INPUT • 720 * 34S PIXEL DISPLAY PLEASE NOTE THIS CARD WILL NOT RUN LOTUS GRAPHICS AND DOES NOT INCLUDE A PARALLEL PORT EPROM PROGRAMMERS FROM MODULAR CIRCUIT TECHNOLOGY MCT-EPROM $129.95 PROGRAMS 27xx AND ZTxrx SERIES EPROMS UP TO 27512 • SUPPROTS VARIOUS MANUFACTURERS FORMATS WITH 12.5, 21 AND 25 VOLT PROG RAMM IMG • MENU-DRIVEN SOFTWARE ALLOWS EASY MANIPULATION OF DATA FILES • SPLIT OR COMBINE THE CONTENTS OF SEVERAL EPROMS OF DIFFERENT SIZES • READ, WRITE, COPY. ERASE CHECK AND VERIFY WITH EASY ONE KEY SELECTION • INCLUDES SOFTWARE FOH STANDARD HEX AND INTEL HEX FORMATS 4 GAMG PROGRAMMER M 89" 10 GANG PROGRAMMER *299« MCT PRODUCTS CARRY A ONE YEAR WARRANTY copyright i987 jdr micro-devices CIRCLE 183 ON FREE INFORMATION CARD 1200B MODEM $9995 K& 2400b modem S19995 MULTIFUNCTION CARDS FROM MODULAR CIRCUIT TECHNOLOGY MCT-MF $79.95 ALL THE FEATURES OFASTS SIX PACK PLUS AT HALF THE PRICE! OMSK DYNAMIC RAM USING 416A. INCLUDES SERIAL PORT. PARALLEL PRINTER PORT. GAME CONTROLLER PORT AND CLOCK /CALEN DA H SOFTWARE FOR A RAMD1SK. PRINT SPOOLER AND CLOCK-CALENDAR MCT-ATMF $139.95 ADDS UP TO 3 MB OFT BIT RAM TO THE A T USER EXPANDABLE TO 1 .5 MB OF ON-ROARD MEMORY <NO MEMORY INSTALLED! FLEX ISLE ADDRESS CONFIGURATION INCLUDES SERIAL PORT. PARALLEL PORT AND CLOCK/CALENDAR OPTIONAL PIGGYBACK BOARD PERMITS EXPANSION TO 3 MH »TMF-SErI»L 2nd serial port '24" MCT-ATMF-MC '29" PIGGYBACK BOARD (ZEHQ K INSTALLED) MCT-MIO $79.95 A PERFECT COMPANION FOR OUR MOTHERBOARD * 2 DHIVE FLOPPY DISK CONTROLLER I N C LU E S S E HI A L PO RT. PA R ALLE L PORT. GAME PORT AND CLOCK/CALENDAH WITH HATTERY BACK-UP SOFTWARE FOH A RAMOISK, PRINT SPOOLER AND CLOCK/CALENDAR MIO-SFJIll 2nd SERIAL PORT *15" MCT-10 $59.95 USE WITH MCT-FH FOR A MINIMUM OF SLOTS USED SERIAL PORT ADDRESSABLE ASCOMl. COM2, COM3 OR COM4 PARALLEL PRINTER PORT ADDRESSABLE AS LPT1 OT LPT2 (n378 OR «278) CLOCK /CALENDAR WITH A BATTERY BACKUP ID-SERIAL 2nd SERIAL PORT '15« MCT-ATIO $59.95 USE WITH MCT-A TFH FOR A MINIMUM OF SLOTS USED • SERIAL PORT ADDRESSABLE AS COM1. COM2, COM3 OR COM4 » PARALLEL PHINTEH PORT ADDRESSAHLE AS LPTA OR LPTB [«378 OR »278| ■ GAME PORT - USES 18450 SERIAL SUPPORT CHIPS FOR HIGH SPEED OPERATION IN AN AT UTIO-JEIIIL 2nd SERIAL PORT '2A" Vol RAM CARDS FROM MODULAR CIRCUIT TECHNOLOGY MCT-RAM $69.95 ,4 CONTIGUOUS MEMORY SOLUTION FOR YOUR SHORT OR REGULAR SLOT SHORT SLOT, LOW POWER PC COMPATIBLE DESIGN CAN OFFER UP TO 576K OF ADDITIONAL MEMORY USER SELECTABLE CONFIG UR ATtON AMOUNTS OF 1 92 r 384. 512. 2S6 & B7GK. USING COMBINATIONS OF 64 & 25GK BAM TO MCT-ATRAM $149.95 A POWER USER'S DREAM, 4MB OF MEMORY FOR THE A T USER EXPANDABLE TO 2MB OF ON BOARD MEMORY USES FULL 16 BIT PARITY CHECKED MEMORY. I 64K OR 256K DYNAMIC RAM FLEXIBLE STARTING ADDRESS, HOUND OUT CONVENTIONAL MEMORY TO 640K & ADO EXTENDED MEMORY ABOVE 1MB MCT-ftTMM-MC *3B« 2MB PIGG TRACK BOARD (ZERO K INSTALLED) MCT-EMS $129.95 2MB OF LOTUS/tNTEL/MICROSOFT COMPATIBLE MEMORY FOR THE XT CONFORMS TO LOTUS/INTEL EMS USER EXPANDABLE TO 2 MB USES 54K OB 256K DYNAMIC RAM (NO MEMORY INSTALLED) USE AS EXPANDED OR CONVENTIONAL MEMORY. RAMDtSK OR SPOOLER SOFTWARE INCLUDES EMS DEVICE DRIVERS. J PHINT SPOOLER AND RAMDtSK <5P Seagate HARD DISK SYSTEMS 20 MB 30 MB $339 $399 Systems include half height hard disk drive, hard disk drive controller, cables and instructions. Drives are pro-tested and warranted for one year. \88seagate40 mb at drive m\ ■ 111 ifettKl WtfM FAST 40ms ACCESS TIME $599 DISK CONTROLLER CARDS FROM MODULAR CIRCUIT TECHNOLOGY MCT-FDC $34.95 QUALITY DESIGN OFFERS 4 FLOPPY CONTROL IN A SINGLE SLOT • INTERFACES UP TO 4 FODs TO AN IBM PC OR COMPATIBLE • INCLUDES CABLING FOR 2 INTERNAL DRIVES ' USES STANDARD DB37 CONNECTOR FOR EXTERNAL DRIVES . SUPPORTS BOTH DS/DD AND OS/OD WHEN U5EOW' DOS 3.2 OR JFORMAT SLOT,, MCT-HDC $89.95 MCT-ftTEMS at version of the mct-ems $139 95 HARD DISK CONTROL FOR WHA T OTHERS CHARGE FOR FLOPPY CONTROL I IBM XT COMPATIBLE CONTROLLER SUPPORTS 16 DRIVE SIZES INCLUDING S, 10, 20. 30 & 40MB . OPTIONS INCLUDE THE ABILITY TO DIVIDE 1 LARGE DRIVE INTO 2 SMALLER. LOGICAL DRIVES • INCLUDES CABLING FOR 1 INTERNAL DRIVE MCT-RLL $119.95 GET UP TO 60% MORE STORAGE SPACE ON YOUR HARD DISK ■ INCH EASES THE CAPACITY Of PLATED MEDIA DRIVES BY 50% > RLL 2.7 ENCODING FOR MORE RELIABLE STORAGE ■ TRANSFER RATE IS ALSO SO% FASTER; 750K ik vs 500K/WC . USE WITH ST 238 DRIVE TO ACHIEVE 20 ■ MB IN A HALF HEIGHT SLOT MCT-FH $139.95 STARVED FOR SLOTS? SA TISFY IT WITH THIS TIMEL V DESIGN I INTERFACES UP TO 2 FDD. & 2 HDD. I CABLING FOR 2 FDOs & 1 HDD ■ FLOPPY INTERFACE SUPPORTS BOTH DS/DD & DS/QD WHEN USED WITH DOS 3.2 OR JFORMAT • ALL POPULAR HDD SIZES ARE SUPPORTED. INCLUDING 5, 10, 20. 30 & 40MB ■ CAN DIVIDE 1 LARGE DRIVE INTO 2 SMALLER, LOGICAL OH IVES MCT-ATFH $169.95 FLOPPY AND HARD DISK CONTROL IN A TRUE AT DESIGN • AT COMPATIBLE. CONTROL UP TO 2 360K 720KOR 1.2MB FDD. AS WELL AS 2 HDDj USING THE AT STANDARD f CONTROL TABLES ■ SUPPORTS AT STYLE FRONT PANEL LED TO INDICATE HD ACTIVITY • 16 BIT BUSS PROVIDES RAPID DATA TRANSFERS ■ FULLY SUPPORTED BY AT HIOS * < illD ■\/ll#>r > SWl Al I IS^AO 1 10 Knowles Drive, Los Gatos, CA 95030 * *JL-/lt I V 111*1 UUCVItrCO Toll Free 800-538-5000 • (406) 866-6200 • FAX (408) 378-8927 • Telex 171-110 THE JDR MICHODEVICES LOGO IS A REGISTERED TRADEMARK OF JDR MtCROOEVICES JOR INSTRUMENTS AND JOR MICRODEV1CES ARE TRADEMARKS OF JOH MICHODEVICES IBM IS A TRADEMARK OF INTERNATIONAL BUSINESS MACHINES 95 CIRCLE 1S4 ON FREE INFORMATION CARD 1200B MODEM $9095 •»-' 2400B MODEM $19995 BARGAIN HUNTERS CORNER NEW FROM RIM ELECTRONICS EXPRESS $ 69« PC/XT SPEED UP KIT * INCREASE THE SPEED OF YOUR PC BY 67% OR MORE! * SIMPLE NO- SLOT INSTALLATION * SOFTWARE OR HARDWARE SPEED SELECTION * 8 MHz V20 PROCESSOR & SOFTWARE INCLUDED * SELECT FOR 3 TURBO FREQUENCIES * EXTERNAL RESET SWITCH * OPTIONAL 8088 8 MHz PROCESSOR AVAILABLE | Cartain at'ly PCs may not run *t a MHx-tn*M macfim f»r b* switched 10 on* of eta ilww •p*wk 6 66 MHi t«% 7,37 MH^5G\ 6.0 MMi=87% PAGE WIRE WRAP WIRE PRECUT ASSORTMENT IN ASSORTED COLORS 327.50 lOOna: 5 5", 6.0'. 6.5", 7.0" 250en: 2.5". 4.5". 5.0" 500>a: 3.0", 3.5". 4,0" WIRE WRAP PROTOTYPE CARDS FR-4 EPOXY GLASS LAMINATE WITH GOLD-PLATED EDGE-CARD FINGERS SPOOLS 100 feat »4.30 500 (Bat 513,25 250 fael $7,25 1000 feet S21 .95 Please specify color: Blue, Black. Yellow or Red EXTENDER CARDS IBM-PC IBM-AT $29.95 S39.95 SPECIAL ENDS 7/31/87 SOCKET-WRAP I.D.™ • SLIPS OVER WIRE WRAP PINS ■ IDENTIFIES PIN NUMBERS ON WRAP SIDE OF SO Ann • CAN WRITE ON PLASTIC: SUCH AS IC II PINS PART;: PCK. OF PRICE S IDWRAP OS 10 1.95 14 IDWRAP14 10 1.55 15 IDWRAP 16 10 1.9S 18 IDWRAP 18 5 1.95 20 IDWRAP 20 5 1.95 22 IDWRAP 22 5 1.95 24 IDWRAP24 5 1-95 23 IDWRAP 28 5 1.95 40 IDWRAP 40 5 1.95 PLEASE ORDER BY NUMBER OF PACKAGES 1PCK. OF) FRAME STYLE TRANSFORMERS 12.6VACCT 12.6VACCT 12.6VACCT 1 25.2V AC CT 2 AMP 4 AMP B AMP 2 AMP 5.95 7.95 10.95 7.95 . r 25PIND-SUB BENDER CNAHQERS $7.95 CAPACITORS TANTALUM I.Offf 15V .35 .47** 35V .45 G.8 15V .70 1.0 35V .45 10 15V ,B0 2.2 35V .55 22 15V 1.35 4.7 35V .65 .22 35V .40 10 35V 1,00 DISC 10pl 50V .05 650 SOV .05 22 50V .05 -OOljrf 50V .05 27 50V .05 .0022 SOV .05 33 50V .05 .005 SOV .05 47 SOV .05 .01 SOV .07 59 SOV .05 .02 50V .07 100 SOV .05 .05 SOV .07 220 50V .05 .1 12V .10 550 SOV .05 .1 50V .12 MONOLITHIC .01 it 50V .14 -V 50V .18 .047*4 50V .15 ■*7jrf 50V .25 ELECTROLYTIC RADIAL AXIAL Iff 2SV .14 V* 50V .14 2.2 35V .15 10 50V .16 4.7 50V .IE 22 16V .14 10 50V .IB 47 SOV 20 47 35V .IS 100 35V .25 100 15V .18 220 25V 30 220 35V .20 470 50V .50 470 25V .30 1000 16V .60 2200 16V .70 2200 16V .70 I 4700 25V 1.45 4700 16V 1.2b DATARASE EPROM ERASER $34.95 • ERASES 2 IN 10 MINUTES _. __^__ ■ COMPACT-NO DRAWER __■ - THIN METAL SHUTTER PREVENTS UV LIGHT FROM ESCAPING ■ 1/4 WATT RESISTORS 5% CARBON FILM ALL STANDARD VALUES FROM 1 OHM TO 10 MEG OHM 10 PCS ssrwvBkM .05 100 PCS same value .02 [ 50 PCS iamevakHt .025 1000 PCS same vahjc .015 , RESISTOR NETWORKS SIP 10 PIN 9 RESISTOR .69 J SIP 8 PIN 7 RESISTOR .59 : DIP 16 PIN 8 RESISTOR 1.09 DIP 16 PIN "IS RESISTOR 1.09 1 DIP 14 PIN 7 RESISTOR .99 1 DIP 14 PIN 13 RESISTOR .99 SPECIALS OH BYPASS CAPACITORS .01 fit CERAMIC DISC 100/S5-00 .01 (if MONOLITHIC 100/S10.00 .1 ^f CERAMIC DISC 100/S6.50 .1 (A MONOLITHIC 100/S12.50, WIS H SOLDERL ESSBI IEADB0J RDS PART NUMBER DIMENSIONS DISTRIBUTION STRIHSI TIE POINTS TERMINAL STRIP(SI TIE POINTS BINDING POSTS PRICE WBUD .38 jc 6.50" 1 100 ™ 2.9S WBU-T 1.38 > 6.50" 1 630 6-95 WBU204-3 3.94 x 8.45" 1 100 2 1260 2 17.95 WBU-204 5,13*3.45" 4 400 Z 1260 3 24.95 WBU20J ! 6.38 x 9.05" 5 500 3 1890 4 29.95 WBLJ-208 8 25 x 9.45" 7 700 4 2520 4 39,95 IBM-PR2 .___ IBM BOTH CARDS HAVE SILK SCREENED LEGENDS AND INCLUDES MOUNTING BRACKET IBM-PR1 WITH -5V AND GROUND PLANE , , , 427.95 IBM-PR2 AS ABOVE WITH DECODING LAYOUT $29.95 S-100 P100-1 BARE -NO FOIL PADS a 115.15 P100-2 HORIZONTAL BUS ,■ , . ■ *.,.;..,,-,., »21 SO PI 00 3 VERTICAL BUS ............ . *Z1 SO PlOO-4 SINGLE FOIL PADS PEH HOLE 422.75 APPLE P5001 BARE . NO FOIL PADS £15.15 P500-3 HORIZONTAL BUS $22.75 P500 4 SINGLE FOIL PADS PER HOLE 421.30 L 7060-45 FOR APPLE Ha AUX SLOT S30.00 PS-IBM SWITCHIHQ POWER SUPPLIES • FOR IBM PC-XT COMPATIBLE • 135 WATTS • :i V @ 1 5A r ■ I ZV @ 4.ZA -5V(£ ,SAh -12V(S .5A • ONE YEAR WARRANTY PS-IBM/ 150 | PS-IBM-150 $79.95 • FOR IBM PC XT COMPATIBLE ■ 150 WATTS * -12V @ 5.2A. .5V (S 18A .12V @ .5A, -5V (K 5A ■ ONE YEAR WAHRAIMTY PS- 130 $99.95 ' 130 WATTS I SWITCH ON HE AH • FOR USE IN OTHER IBM TYPE MACHINES ■ 90DAYWAHRANTY PSA $49.95 ■ USE TO POWER APPLE TYPE SYSTEMS. 7S.5 WATTS *+SV@7A, »12V(S3A -5V m .5 A. -12V g .5 A ' APPLE POWEH CONNECTOR i PS- 1558 $34.95 . 75 WATTS. UL APPROVED ■ -SV@7A, -12V (J) 3A -12V@>Z50ma. -5V@ .lOiVi.i BOOKSby STEVE CI B1ULD YOUR OWN Z80 COMPUTER $19.95 CIRCUIT CELLAR VOL 1 517.95 CIRCUIT CELLAR VOL 2 318.95 CIRCUIT CELLAR VOL 3 S1S-95 CIRCUIT CELLAR VOL 4 $18.95 . CIRCUIT CELLAR VOL 5 S19.9S LITHIUM BATTERY AS USED IN CLOCK CIRCUITS 3 VOLT BATTERY $3.95 , BATTERY HOLDER S1.49 MUFFIN FANS SO 14.95 3-03" SO 3.18" SQUARE 16,35 6 LINE CORDS dueler .33 3 conrfucti ductar w female socket EMI FILTER $4.95 | 3 15' SO- 14.95 3-53" SO 14.95 3.15" SQUARE 16.35 | 2 conductor .33 3 conductor -99 3 conductor w fomelc sockat 1,49 2 VOLUME SET IC MASTER THE INDUSTRY STANDARD $129.95 ol 96 Visit our retail store located at 1256 S. Bascom Ave. in San Jose, (408) 947-8881 || \^y I\ /ll*~*6*/^/~^Ck\ fMlT*QB PLEASE USE YOUR CUSTOMER NUMBER WM •JLvIl I V lll^rl vJtJIjrV I V*trO IERMS Mmimum SIC 00 Foi pping and handling im . _^ , ai Ar/^A Ground and S3.50 tor UPS An. Orders over 1 lb. and foreign 110 KnOWleS DriVe, LOS GatOS, CA 95030 .rdditailfllihippingrhargriS -pleaseeonlactoursalesdepartmen aai i-*r* #«M«#fc restdenls musl include applicable sales tan Allrnerchandiseisw Toll Free 800-538-5000 • (408) 866-6200 «*« o»w«i*i :sui«i puck an.- subtuci io change wimoui responstble tor lypographscol error*. We reserve Ihe n^hl :■ lin FAX (408) 378-8927 • TeleX 171-110 substitute manulaclurei All rrKrchandLse subject So pool sale- y^^ COPYRIGHT 1987 JDR MICRODEVICES THE JDR MICRODEVICES LOGO IS A REGISTERED TRADEMARK OF JDR MICRODEVICES. JDR INSTRUMENTS AND JDR MICRODEVICES ARE TRADEMARKS OF JDR MICRODEVICES IBM IS A TRADEMARK OF INTERNATIONAL BUSINESS MACHINES APPLE IS A TRADEMARK OF APPLE COMPUTER CIRCLE 185 ON FREE INFORMATION CARD Radio /hack Part/ Place THE BUILDER'S STORE! OVER 1000 COMPONENTS IN STOCK Communications Circuit Book «|49 A Must For Project Builders The latest of the "hands- on" electronic- project books by Forrest M, Mims in. Includes projects (or wired and wireless voice and code systems, shortwave listening and much more. Contains 48 pages with schematics. #276-5015 Unusual Buzzers (5) Trl-Sound Alarm. Contains an IC. driver circuit and 8-ohm speaker. Three distinctive sounds. 3 VOC. #273-072 5.95 (6) Electronic Chime. Melody- synthesizing EC and speaker combo produce a pleasant "ding- dong" sound. Operates 6 to 18 VDC. #273-071 7.95 Deluxe Enclosures Vented steal tops, easy-to-work aluminum chasis. With protective rubber feet and hardware. S.ze Cat. No Each 3V.x2Vex4" 4x2%x 6" 5V« x 3 x 5W 270-251 270-252 ??n.?53 2.99 3.99 4.99 Archer^ Hand Tools Professional Quality (13) 5V«* Long Nose Pliers. Spring return, insulated grips. #64-1812 5.99 (14) 4'/2" Diagonal Cutters. Spring return, long lasting and in- sulated grips. #64-1813 5.99 (15) 6" Locking Forceps. Use as a temporary heal sink and to pick up or hold parts. #64-1866 . 4.95 Attention-Getting LEOs (1) Super-Bright Red. Outputs 300 mcd, 20 mA #276-066, 1.19 (2) Blinking Red. MOS driver and red LED combo. #276-036 . . 1.29 (3) Blinking Green. #276-030 1.29 (4) CdS Photocell. Mated 200 mW, 170 volts. #276-116. 1.79 Panel Switch Values (7) Lighted SPST Normally Open or Normally Closed. Rated 5 amps at 250 VAC. 12-volt lamp. #275-676 S.95 (8) SPST Rocker Switch. Rated 6 amps, 125 VAC #275-690 . . 1.89 DPDT. #275-691 2.49 (9) SPDT Mini-Toggle. Rated 5 amps. 125 VAC. #275-603 . . 1.49 Miniature PC Pots Rated at Vs-watl. Sealed against noise-causing contaminants. Ohms Cat. No. 1k 10k 25 k 100k 271-333 271-335 271-336 271-338 Archer coax Cable Low As per foot Low loss— no more than 4.0 dB per 100 feet at 50 MHz. RG Type Ohms Vel Fact. Cat. No. Price Per Ft. 8' 8 58 59 52 52 52 75 66% 75% 66% 75% 278-1323 278-1328 278-1326 278-1327 .36 .21 .16 .16 •NEW! 95% Shielding. Hotline" Save With our Order Service We send your order directly to the Radio Shack near you. We pay the postage. Delivery time on most items is one week. Your Radio Shack store manager can special-order a variety ot parts and ac- cessories not listed in our catalog— tubes, linear and digital iCs, diodes, transis- ' / tors, crystals, phono cartridges and more. There's no minimum order requirement for this convenient ser- vicel Your order will be sent to your nearby Radio Shack store, and we'll notify you when it arrives. %> Put These High-Tech ics to work (10) <11> WW With Data, Circuit Sampt (10) SP0256-AL2 Speech Synthesizer. MOS/LSI device with built-in pro- gram easily interfaces with most computers. Requires 3.12 MHz crystal (special order via ■'hotline" above). 28-pin DIP. #276-1784 12.95 (11) CTS256-AL2 Text-to-Speech tC. Preprogrammed 8-bil processor translates ASCII into control data for figure 10. Requires 10 MHz crystal [special order). 40-pin DIP. #276-1786 16.95 (12) SSI 202 Touch-Tone Decoder IC. Easy-to-use OTMF receiver is just right for remote-control applications. Requires a minimum of support parts and is easily interfaced with most microprocessors. #276-1303 .... 12.95 Tantalum Caps Maximum Capacity In an Extremely Small Package Low As 49* Each IC pin spacing . 20% tolerance. F WVDC Cat. No. Each 0.1 0.47 1.0 35 35 35 272-1432 272-1433 272-1434 .49 .49 .49 22 10 22 35 16 16 272-1435 272-1436 272-1437 .59 .69 .99 28-RangeFETVOM Top-Quality Memory Upgrade Your Computer 4164 64K Dynamic RAM. 150 ns access time, low-power design (230 mW, typical). Single 5 VDC supply. #276-2506 3.95 TMS 4256 256K Dynamic RAM. 150 ns maximum access, low- power 16-pin DIP with specs and pin-out. Single 5 VDC supply. #276-1252 6.95 Dual-Tracking DC Supply Big 5" Color- Coded Scale Works like a solid-state VTVM! Super-sensitive — 10-megohm input impedance. With 28 ranges and "beep" continuity. Includes test leads and spare fuse. Requires one 9V and one "C" battery. #22-220 Delivers stable DC with extremely tow ripple at precisely the voltage you need. Adjustable from to 15 VDC. or series output provides up to 30 VDC. Selectable independent or slave operation of two voltages. Meter for monitoring voltage or cur- rent of either output. UL listed. #22-121 69.95 Over 1000 items in stock: Binding posts, Books, Breadboards, Buzzers, Capacitors, Chokes, Ciips, Connectors, Fuses, Hardware, ICs, Jacks, Knobs, Lamps, Memory Chips, Multitesters, PC Boards, Plugs, Power Supplies, Rectifiers, Relays, Resis- tors, Switches, Tools, Transformers, Transistors, Wire, Zener Diodes, more! Radio /hack A DIVISION OF TANDY CORPORATION Prices apply at parmeipating Radio Sriack stores and oaicrs CIRCLE 78 ON FREE INFORMATION CARD > C a c CO CO -J 97 illMIU'lJl^- fJilMlllUilJilSl ALL ELECTROMCS CORP. (ml m^mmm mm SPRING LEVER TERMINALS is Two color codtd twminats on a alurdy 244" x 3 ' < bakelita piste Gnat tor speaker cndoiurcs or power supplies. 75* EACH 10 Jot $6.00 FUSES Q^^J 3AG (AGO SJZE ], 1^.2.2^.3.4. 5, SAMP 1.2.3,4. SAMP 1**^=*» 5 of j ny ON E am perage 7 $ -: ^PHOTO-FLASH CAPACITORS ^170 MFD 330 Volt CAT! FPC-170 "7 5c each 400 MFD 330 Volt CAT) PPC-4 00 $1.00 ea LIGHT ACTIVATED MOTION SENSOR This device contains a photocell which scuS'.-i sudden changes in ambient liqht . When an object or person passes., within it's field of view (about b") it beeps for several seconds then resets Could be used as a door annun- ciator or modified to trigger other devices. 5 1/2" x 4" x J . Operates on 6 Vdc Requires 4 t\h batteries (not included)* CATi LSMU S5.75 pet unit SOUND EFFECTS BOARD PC board with 2 1/4" speaker, 2 LEDsh IC h battery snap, other components 2 3/8 p x 3". When switch is pushed board beeps and Leds lightl r. Operates on 9v battery (not included) Experimenter ' s delight' CAT* ST- 3 SI. 2 5 ea. 4 inch paper COMMODORE PRINTER PLOTTER Commodate ModM * 1520 Feu* cok* X-Y plotter, standard VIC sana! in I. efface allows easy connection 10 Commodorg 64 compuEnrg. Up TO 80 ch&raciera. par iwe. CAT I CONM520 $49.95 each EXTRA pen seta $1.50 per set. MINIATURE TOGGLE SWITCHES ALL ARE HATED 5 AMPS® 125 VAC COMPUTER GRADE CAPACITORS 1,*V00 mfd, 200 Vdc 3" X 2" dia. 52.00 6,400 irrfd 60 Vdc 4 1/4"* 1 3/8" dia.SJ.50 7,500 mfd 200 Vdc b 3/4" x 3" dia. S4 .00 12,000 mfd 40 Vdc 4 1/4" x 2" dia, $2*50 22,000 mfd 25 VdC 4 3/4 H x 2" dia. 52.50 48,000 mfd 10 Vdc 3" v. 2 1/2" dia. $2.50 66,000 mfd 15 Vdc 3 3/4" x 3" dia. S3. 50 72,000 mfd 15 Vdc 4" v- 2"' dia* $3.50 100,000 mfd 10 Vdc 6" x 2 1/2" dia. si. 00 S.P.S.T. CARLING (on-off J TOGGLE RATED. SWITCH L0 flm P § 125 Vac. All plastic body and toggle. CAT! 5T5- $1.00 ea 10 for$8.50 100 for $7,50 LARGE QUANTITIES tail light, emergency warning light, or special^ef f ects lamp. Red reflective lens is 2 3/4" jc 5 1/2" is mounted on a 4* high pedestal with up^down swivel ad justment. Includes 12v replaceable bulb* CATt TLB $3.95 each. XENON FLASH TUBE 3/4" long X 1/8" dia- Flash tube designed (or use in compact camera flash units. Ideal lor experimenTcrs. CAT* FLT-1 2 lor $1.00 LED'S STANDARD JUMBO DIFFUSED T 1-3/4 RED 10 for $1-50 MICRO-CASSETTE MECHANISM Micro-cassette tape transport for standard MC60 or MG45 micro .casSfitlas. 3 Vdc operation. Contains: drive motor, belt, head, capstan, pinch wheel and other components. 3 1/2" X 2 1/4" X 5,'8 _ CAT* MCMEC $3.00 each 10 lor 127.50 GREEN YELLOW 10D tor 113.00 10 (or 12.011 100 lor 117.00 to lor 12 00 100 tor 117.00 I FLASHER LED 5 volt operation red jumbo T 114 sue GMtlEChl $1.00 NEW GREEM FLASHER CATILSD-tG $1.00 BIPOLAR t jumbo Tissue 2 lor SI 70 48 KEY ASSEMBLY FOR COMPUTER OR HOBBYIST LED HOLDERS „ Two piece holder ^^ rR Fw jumbo LEG lOforSS* 100 lot 35. (X? CLEAR CLIPLITE LED HOLDER Mane LEDa fancy j indicator. Clear. 4tarfljM D.RS.T. LIGHTED ROCKEH SWITCH IHrrte irotitsti rocker. snap mounts in it'xiWi hole Orange lens 16 amp contact $1,50 MINI-PUSHBUTTON S-PS.T. momentary normally opAn %- bushing 35t*Jcn Bed tjutton. ^ o to T $3.00 SNAP ACTION SWITCH Cherry elect. *E-2i. N.O.mN.C, Q.1A contacts. SuttaWe ror alarms and other low energy circuits 11a" lever. AStEACH 10 FOfl 14.10 WALL TRANSFORMERS all plug dircctsyii into 120 vac outlet 4 VDC ■ TO mi. VAC Q 500 ma. 6 VDC a ™ me- SVDCrssoOms. 12.5VAC«S2S5me. IB VAC ffl 11 VA and 4.5 VAC & 1.ZB VA 24 VAC @ 250 m >. MULTI- VOLTAGE tfy 500 12' 12 00 13.50 14.50 15.00 13.00 «.so 13.00 3,4Vl,S,7Vi,(or12VDC 17.50 TRANSISTORS 2N70S 2N2S22A PM22S2A 2N2904 ZN2905 MJ2955 2K3055 PHD 10K40 TIP 1J1 TIP 125 4lqr$1.00 3 (or 11.00 4 tor 11 .00 3 tor 31.00 3torii,00 11.50 (1.00 11.00 75* 75t WE'VE MOVED Our Mall Order Operation* NEW u> " rv * Ub#t MAILING ADDRESS P.O. BOX 567 NEW T.I. KEYBOARDS. OrvjhaHy used on computers, these key- boards contain 4B S.P.S.T.mech- anical switches- Terminates to _ 1 5 din connector. Frame4 _ x9" CATt KP- 48 11.50 ...„ I VAN NUYS, CA 91408 EDGE CONNECTORS ALL ARE. 156' SPACING. *rfillt tiwitiiimttrtnunii 12 EDGE CONNECTOR 11.25 •• solderlogstyle lOforltl.OO 22/44 EDGE CONNECTOR 12.00 H RC.slyla 10 lor 115.00 22/44 EDGE CONNECTOR soloertug style 12.50 each 21'5S EDGE CONNECTOR RC styla 12.50 « 3«/72 EDGE CONNECTOR RC. style 13.00 >lcn 43/16 EDGE CONNECTOR RC.styra H.SOeich WALL TRANSFORMER 11.5 Vdc \^\ 1-« Amp. 1 ^ r INPUT: SIZE: 120 Vac 3 3/4" X 2 7/8" X 2 5/8" CAT t DCTX-11519 S6.50 ooch TRANSFORMERS 120 volt pnmarira m 2K 10 TURN MULTI -TURN POT SPECTROL #MOD534-Tl6l iA VOIH & 750 ilia. 6.3 VQlt it SOD mi. 13 V.CT. & 200 mi. 12 «CT, £t 400 rn*. 12 V.C.T. & 1 «T»p 11 V.CT. & lamp 12 VrC-T. %% * *mf\ 11 will ffl 660 mi. 14 V£-T. © 100 ma. 24 V.CT. o i amp 24 V.CT ft 2 imp 24 V.CT. ® 3 imp 24 V.CT. O 4 amp J3.00 II. 75 12.00 13/00 (*.OD S4.B5 4700 S2 .00 S2.50 J4B5 S6.7S (11.00 RELAYS 10AMPSOUDSTATE lONTROL^-JSv^c r®J*\ LOAD: 140 vac 10 amp 1 , V € -^r?- jIZEj 2MT il-il 1 iiiXj 19.50 EACH 10-FOR *90.00 ULTRA-MINIATURE 5 VDC RELAY Fujitsu 9 FBR£1tNEO0O5M20 Htan sensitivrty COIL: 120onm5 CONTACTS: lamp Mountain 14 pin DIP socket H.25»Kti 10torI10.MI MINIATURE 6 VDC RELAY Aromat #RSO-6V Super Small S.RD.T relay GOIdcolDali contacts rated 1amp@30vdc Highly sensitive, TTL *act dtiva possibw 1 20 ohm coll. Oparale Irwti 4.3-6 vdc COIL: IZDffin-,5 S1.5BHCH l'/n ""/«'" 7.|' 10 lor 11 3.50 13 VDC RELAY CONTACTS: SRN.C 10anq>@12rjyac Energizocoilto open contact . . . COIL" 13 vdc 650 ohms S PE C1AL PBIC E 5 1 . 00 n a c h 4PDT RELAY 14 pin KH style... 3 amp Kmtacts . USED Put tuny tostad . , ,1.1.70 each spGiiry exja voltage desired Eathef 24 vdc or 120 vac LARGE QUANTITIES AVAILABLE SOCKETS FOR KH R ELAT 75c tach Tl SWITCHING POWER SUPPLY Compact., wflJI-rt^kJljiEecl switching powef supply designed ic^ power lexas lnal^mErnisoofTipy!«?f INPUT: M - 25 vac ®1 amp ■ >rt L IiRL OUTPUT *l?vdc@350ma. PRICE * 5 vdc @ I 2 amp - 5 vdc @ £00 SIZE ^^'xi'.i' Rl'ii-lT™ sr % 3 50 13.8 VDC REGULATED POWER SUPPLY Trifl&G are sotid ata(o. fully ■■oflLrlaiad 13.& vdc power supplies. Bom Feature 1 &&*<> solid stele ■ccwisUuclJon, (use protection, and L E.D.poww Indtcaior. u. L listed 2 ampionatont, 4 nmpiLirgn $20.00 each 3 emp eomtnit.. S amp turg* $27^0 *ach TELEPHONE JEl COUPLING %& TRANSFORMER Stincor t TTPC4I SOOchmf c.l. 1o BOO rjhmi c.l P.C. board mount W"it5fl"n3W" SOUND AND VIDEO MODULATOR TI#Urtl3&l-l Designed for use with T.I- computers. Can o-e used with video cameras, gaffies or other audio/video sources. Built in A/fl switch enables user to switch from T.V. antenna without disconnection Channel 3 or * seletion. Operates on 12 Vdc. Hook-up diagram included. CAT* AVMOD S5.00 each RECHARGEABLE NI-CAD BATTERIES AAA SIZE 1. 25V $1 3 5 AA SIZE 1.25V SOOmAH $1.85 AA ,m: :,-: :.::■ $2.00 C SIZE 1.2V l.'ji.:niAr S3. 50 SUB-C SIZE soldeMati $3.50 SIZE ] 2V 120rjmAH $3.50 NI-CAD CHARGER TESTER Will charge most every size Hi-cad battery available Cat! UHCC-H S12.50 8" 15 WATT SPEAKER C.T.S Model SB3079 ^£ Full range speaker. tVyp^S 100-io.tsooHi: **(C\W Ideal Tor PA syat&rm. (t-^ffj Mounting lutes for line-matching tranilormei. CATaSKJUS 13.50 *a. Cast of B pea. 125.00 par case LJ g Q < LC 98 STORES LOS ANGELES, CA 905 S. Vermont A VI. 213 360-8000 VAN NUYS. CA $228 Sepulveda Blvd. SIB 397-1 80S MAIL ORDERS TO: ALL ELECTRONICS P.O. BOX 587 91408 TWX- 101010163 ALL ELECTRONIC QUANTITIES LIMITED minimum ortoERE sio ci, TOLL FREE ORDERS CALIF. ABO SALES TAX 800-826-5432 USA: S3.D0 SHIPPING NOC.O.D.I FOREIGN ORDERS: INCLUDE SUFFICIENT SHIPPING. INFO • (213) 380-8000 FAX - (213) 389-7073 POLARITY SWITCH external coaxial relay on a v satellite TV system. IDEAL FOrVI^ 553 THE EXPERIMENTOR AS PARTS,?; Heavy chassis box containing a **™ CA 358 op ampl and other parts. Catalog I rdfs SI. 7 5 each 10 for S15.0Q SOLID STATE BUZZER Star #SMB-OBL 6 vdc TTL compatiWa. Sl.&Dfl&ch 10 lor $9.00 CIHCLE 107 ON FREE INFORMATION CARD that's New at AMERICAN DESIGN COMPONENTS? "The Source" of the electro-mechanical components for the hobbyist. We warehouse 60,000 items at American Design Components — ex- pensive, often hard-to-find components for sale at a fraction of their original cost! You'll find every part you need — either brand new, or removed from equipment (RFE} in excellent condition. But quantities are limited. Order from this ad, or visit our retail showroom and find exactly what you need from the thousands of items on display. OpenMon. - Sat., 9-5 THERE'S NO RISK. With our full 90-day warranty, any purchase can be returned for any reason for full credit or refund. ADAM COMPUTER. 5 X A" DISK DRIVE Gives your Adam fast, reliable data storage and retrieval. Can hold up to 16GK bytes of information. Uses industry- standard SS/DD disks. Connects directly to your Adam memory console. Comes with disk drive power supply* Disk Manager disk and owner's manual, Mfr - Coleco, Model 7817 Item #12630 $199.00 New ADAM Accessories. . . ADAM COMPUTER KIT - (Less printer.! Includes: Keyboard, digital data drive. 2 game controllers, power sup- piy, all memory boards* and one cassette. No wiring necessary; hook-up diagram incl. Hem #7410 $99,00 COLECOVISION to ADAM EXPANSION KIT - Plugs into your Colnco Vision. With printer power supply & one data drive, you'll have & working Adam Computer! Keyboard & one Smart Basic cassette also included. Item #3318 $59.50 ADAM PRINTER - Item #BB39 $69.50 DATA DRIVE - Item *6B41 . LASTCHANCE- $19.95 PRINTER POWER SUPPLY - Item #6642 $14.95 ASCII KEYBOARD - Item #6643 $19.95 CONTROLLERS - ISetof4) ltem#70T3 $9.95 ADAM CASSETTES - (Consisting of Smart Basic, Buck Rogers fit blank cassette.) ltem#77BB jij -. - BAKERS DOZEN - $19.95 LOGIC BOARD- tPartsonly.l ltem#7231 $9.95 GAME BOARD- IPartsonly.l Item #7679 $6.95 ADAM LINK MODEM - (Software included.) Item #12363 $29.95 AUTO -DIALER ADDRESS BOOK - . „ „ Item #12365 $19.95 PC 8300 HOME COMPUTER (Advanced version of the Umax 1000] 42-key mechanical keyboard I not membrane). Contains 2K of RAM. Reverse video. 2 BOA, 6.5MHi processor, ROM 8K BASIC. Graphics capability/sound- music, TV or monitor. Joystick input operates on 115 VAC. In- cludes: AC adapter, TV cable, and pair of cassette cables. Will run ell prerecorded tapes for Sin- claWTimex 1O0O-ZX81. Mfr - Power 3000. In orig. boxes. Item #10336 $29.95 New Accessories. . . * 1 6K RAMPACK upgrade Item #10337 $9.95 New * 32K RAMPACK upgrade Item #12148 $19.95 New * COLOR PACK Item #12147 $19.95ljew 12", High Resolution TTL MONITOR Z%", 10Mb HARD DISK DRIVE {IBM® Compatible) Fits standard S&" spacing. Shook mounted. High speed, low power. Mfr — Rodime #H0252F Item #10151 $159.00 New Controller Card for above Item #10150 $89.00 5 1 /i" FULL HT. DISK DRIVES 48TPI [IBM' Compat.) Double sided /double density, full height drive, 48 T.P.I. , 80 tracks. Mfr - TandonTM 100-2 Item #7328 $79.95 2 for $150.00 96 TPI, DS/Quad Density Mfr - CDC #940ST Item #1893 $99.00 SWITCHING POWER SUPPLY 12 VDC/110 VAC Iw/built-in power supply}. Green phosphor. Mtd. in metal housing- Schematic supplied. Mfr — Ca patron ic #05-1030: .„_ _.-_ Item #BB11 $19.95 New 115 & 230V, 47-440 Hz. Inputr 9Q-135V7180-270V Output: 5VDC@5.5A + 12VDC@.4A - 1 2VDC @ ,3A Perforated metal case enclosure, Dim.:9rt-Lx3>S-Wx2"H. Mfr — General Instrument Item #79B3 $14-.95Nev 5%\ 1.2 Mb. AT HALF HT. DISK DRIVE 48/96 TPI (IBM"" Compatible) Double sided, single/double density; 80 track. Mfr - Panasonic #JU-475 Item #10005 $119.00New 5%" 1 12 HT DISK DRIVE DOS 3.2 Compatible 96 TPt, DS/QUAD DENSITY Tan don TM55-4 DS/Quad Item #1304 $79.00 2 for $150.00 COMPUTER GRADE POWER SUPPLY Other usas-rvns CB & car radios. Comas ready to pkig in? DC Output: - 5V @ ,5 amp. + 5V @ 3 emp. + 12V @ 6 amp. Input 115VS60H. Dim.: 9M "W x3#'H. LRubterft-ifKlL) Item -9501 $24 95 New 15" COMPOSITE VIDEO . MONITOR \ i 15*, green phosphor, high reso- lution [1 2 tines center) and: band- width from IOHi to 30Hj ± 3dB. Operating volt. : 120/240VAC, 50/60H1-, 65VA max. Mfr — Motorola - Alpha Series hem #10044 $34.95 New Insides of the Commodore Computer ^! . Commodore VIC 20 CPU board & mechanical keyboard. Guaranteed not to work, (For parts only.) Item #12144 $14.95 RFE Hl-POWER SWITCHING POWER SUPPLY Output; *5,15V@>70A + 1 2V ® 4A + 1 2V fi> 4A + 5.2V@5A Input: 11 5/ 2 30V nominal, .72SKW cont, 47-63HI. En- closed in metal housing. Dim.: 15"Wi( 2Vi"Hx6" deep. Mfr - Todd Prod. #4XS8 1 S 1 A Item #9749 $29.95 New PUMPS-COMPRESSORS-BLOWERS-MOTORS- POTENTIOMETERS- COUNTERS TIMERS -RELAYS -VOLTAGE REGULATORS -POWER SUPPLIES 1 -PIECE TELE- PHONE Touch- tone to rotary (may be used even where there is only a rotary phone]. Features: I a si number radial & mute button. Comes w/15" cord & standard modular plug. Color: Ivory, Mfr — Spectra -phone. Modal OP-1. Item #10748 $6.95: 3 for $15.00 New JOYSTICK CONTROLLERS Fits Atari, Apple, Commodore. and our #10336 PC8300 Com- puter. Has 4-ft. cord with plug. Dim.: 3)4" sq. xl ft" H. Item *12143 $5.95 New 12/24VDC MUFFIN- TYPE FANS V'V 55/100 CFM S W. Can be mounted lor blow- ing or exhaust- Aluminum hous- ing, ptushless, ball-bearing type. 1 " Thin: 5 plastic blades with feathered edges. Mfr - Centaur KCUDC24K4 601 ltam#B541 $19.95 New 1 Vj" Standard: 5 plastic blades Mfr - Centaur #CNDC24K4-601 Item *1 21 03 $14.95 RFE AT-STYLE COMPUTER CABINET Contains 1 tulMength expan- sion slots (w 'guide si. With room for an internal 5 V* " hard disk drive. Has 3 half-height disk drive slots. Rear on/off switch, notched to hold in power supply I not incl.h and security switch w/key. Item #12266 $49.95 New AMERICAN DESIGN COMPONENTS, 62 JOSEPH STREET, M00NACH1E, N.J. 07074 YES3 Please send me the following items: How Many? Description Price Item No. Total Shipping & handling, we ship UPS unless r"-~^_^ otherwise specified. Add $3 plus 10% total. / ^c"^~~~-~^ Canadian: S3 plus P.O. cost. Charge only. / C 4Tai n^8?~~~ > SalES Ta * (N - J - ™siaents only. 4*W) gl u G s 9n / please add 6% of total) ^^23^0ro< B ; / ORDER TOTAL 1 D My check or money order is enclosed. [1 Charge my credit card. □ Visa n Master Card Q Amex Card No. MINIMUM ORDER S15 RE- 8 7 E*p. Pate Signature Telephone: Area Code Number Name Address City State Zip J AH inquiries end f/ee catalog requests Cat/ 201-939-27W. For all phone orders, ca// TOLL- FREE 800-524-0809. In New Jersey, 201-939-2710. > c o c 03 CO CO 99 CIRCLE 195 ON FREE INFORMATION CARD THIS 45 SQ. INCH t^PB LIGHT PANEL IS .035 INCH THICK PRODUCES NO HEAT COMES IN 3 BOLD COLORS HAS ITS OWN 12 VOLT POWER SUPPLY ANDTHATS WHY WE CALL IT, iTS4 ' They were developed by the computer industry a: hi- tec LCD. back lights you can bend and Lwist them into almost any shape, Tbe white one turns a brillant coiboll blue, The pink one turns bright while, The green one, veil it looks like the power source from a space ship! A manual explains how they work and the assembly directions are clear. Even the solder is included! EACH 139 KIT INCLUDES: 1 INSTRUCTION MANUAL WITH THEORY SECTION SEND !5 (APPLIED 70 PURCHASE) FOR THE MANUAL ON LI 5:L1GHT PANELS: 1EA 10 INCH BY -j.5 INCH (SPECIFY WHITE 0! BLUE) 1EA 9.3 INCH BY 2.5 INCH (pink that turns white) 3EA 9.5 INCH BY 2.5 INCH [MELT DOWN GREEN) I:POWESSUPPLYKIT 15 DHY mOIlEY BflCK THIHL Call for a copy of t S do* trial agreement. Tax & rrenht extr».5end check pr arid 1.90 far COD. Price mes change Store Price mt* differ. While supplies leat. Ho POe* terms > or credit ctrdj S iliconValle y S urplus 415-261-4506 4401 OAK PORT OAKLAND CA, 94601 OPEN 1 0am- 6pm CLOSED 5UN&M0N CALL OUR BBS 415-261-4513 CIRCLE 186 ON FREE INFORMATION CARD miM d SCIENTIFIC & ELECTRONIC PRODUCTS PLANS— Guild YourseSF— All Puts AvailaMe In Stock • LC7— BUflNING CUTTING COa LASf R S 20.00 ■ RUM-POKTABLE LASER RAY PISTOL „ 20.00 • TCC1— 3SEPABATETESLA00IL PUNS TO 1.5 MEV 20.00 • IOG1-I0N FUVGUN 10.00 • GRA1 —GRAVITY GENEflATOFt 10.00 « fMLI-ELECTRO MAGNET COtL GUNJUUHC KITS • MFT1 K-FM VOICE TRANSMITTER 3 Ml RANC ■ VWPM5K-TELEPH0NE TRANSMITTER 3 Ml • 6IC3K-250.00 VOLI 10-H" SPARK TESIA • LHC2K- SIMULATED MULTICOLOR LASER.. ■ BLS1K-1 00,000 WAn BLASTER DEFENSE [ 'ITM1K-10O.O0O VOLT 20' AFFECTIVE RANGE INTIMIDAT0R HER 6.00 E 49.50 WNGE 39.50 MIL 199.50 39.50 PACE 69.50 B9.50 • PSP4K— TIME VARIANT SHOCK WAVE PIST0. • RTG1K-SPECTACULAR PLASMA TORNADO GENERATOR 59.50 149.50 • MVPIK SEE IN DARK KIT ASSEMBLED • PG7OH-MULTICOL0RE0 VARIABLE MODE PLASMA GLOBE "7" • BTC10-50.000 VOLT-WORLD'S SMALLES TESLACOIL 425.00 44.50 • LGU40-1MW HeNe VISIBLE RED LASER GU • TAT2D AOT0 TELEPHONE RECORDING 0EVIC • GPV10-SEE IN T0TAI DARKNESS IR VI EWE « UST10-SN00PER PHONE INFINITY TRANSt • IPS70-INVIS1BLE PAIN FIELD GENERAT0R- MULIIMODE • CATALOG CONTAINING DESCRIPTI0 HUNDREDS MORE AVAILABLE FOR $1 . (X WITH ALL ABOVE ORDEFtS. PLEASE INCLJDE S3. 00 PH ON ALL K PLANS ARE POSTAGE PAID. SEND CHE OS F0NDS. INFORMATION UrJ P.0.B0X716DEPT.RE.AMH 1 299.50 E 24.50 1 299.50 co o z 1 ts HI _l LU 6 Q < or mEfi 169.50 M.W js of above plus or include free is and products ;k,mo,visa,mcin LIMITED IRST, NH 03031 ADVERTISING INDEX RADIO-ELECTRONICS does not assume any responsibility for errors that may appear in the index below. Free Information Number Page 81 A.I.S. Satellite 79 108 AMC Sales 29 107 All Electronics 98 103 Allen W.O .....38 — Amazing Devices , 100 195 American Design Components 99 98 Beckman Industrial . 3 85 Blue Star Industries 78 109 C&'S Safes 14 — C.O.M.B 16 60 CIE 34 89 Cameo Enterprises 79~~ 54 Chemlronics 33 196, 19S Circuit Cellar 78, 79 — Command Productions . . 29 203 Computer Technologies ............. 72 194 Cook's Institute 24 193 Crystek 8 200 Dactron , 12 127 Dsco Industries 78, 79 189, 190 Dick Smith Electronics 90 82 Digi-Key 87 — Electronic Technology Today . 78, 79 CV3 120 Elephant Electronics 24 111 Elronix 81 10O Firestik II 29 188 First Street Computer 26 — Fordham Radio 10 — Grantham College of Engineering 5 86, 176 Heath 9. 20 — ICS 8t 65 J& W IS 59 JDR Instruments 7 1 13, 182 JDR Microdevices 92, 93 183, 184 JDR Microdevices 94, 95 185 JDR Microdevices 96 114 Jameco 88, 89 104 Jan Crystals 33 87 MCM Electronics 91 204 MD Electronics 79 93 Mark V. Electronics 85 205 Mercer 13 61 Microprocessors LTnltd 72 — NRI 11, 17 187 NTS 79 — Ncsda 28 202 NuScopc Associates. . , 72 191 OCTE Electronics 79 110 Omnitron 31 — Pacific Cable 83 181 Parts Express 84 101 Pomona Electronics CV4 78 Radio Shack 97 177, 178 Sencore 21, 23 179, 180 Sencore 25, 27 186 Silicon Valley Surplus 100 74 Solid State Sales 86 94 Star Circuits 79 92 Tektronix CV2 66 W.S.Jenks . . . ... ..... ... 26 Gernsback Publications, Inc. 500 B Bi- County Blvd. Farmingdale, NY 11735 (516) 293-3000 President: Larry Stockier Vice President: Cathy Steckler For Advertising ONLY 516-293-3000 Larry Steckler publisher Arline Fish man advertising director Shelli Weinman advertising associate Lisa Strassman credit manager Christina Estrada advertising assistant SALES OFFICES EAST/SOUTHEAST Stanley Levi tan Eastern Sales Manager Radio- Electronics 259-23 57th Avenue Little Neck, MY 11362 718-428-6037, 516-293-3000 MIDWEST/Texas/Arkansas/ Okla. Ralph Bergen Midwest Sales Manager Radio-Electronics 540 Frontage Road — Suite 339 Northfield, IL 60093 312-446-1444 PACIFIC COAST/ Mountain States Marvin Green Pacific Sales Manager Radio-Electronics 15335 Morrison St.— Suite 227 Sherman Oaks, CA 91403 818-985-2001 100 Electronics Paperback Books EVERY BOOK IN THIS AD $6 OR LESS! m M ^ n BP12S— 25 SIMPLE AMATEUR BAND ANTENNAS 55.00. All are inexpensive to build, yel perform well. Diodes, beams, triangle and evert 3 mini rhombic. D BP12B-^0 PROGRAMS FOR THE ZX SPECTRUM AND 16K ZX8Z SS.7S. Included wilh each program is a flow charl and a description ol what happens. Notes for converting programs lor use on other computers are also included. □ 160— COIL DESIGN i CONSTRUCTION MANUAL., ...55.95. How the hobbyisl can build RF. IF, audio and power coils, chokes and transformers. Covers AM, FM and TV applications. D JOB— PRACTICAL STEREO t QUADROPHONT HANDBOOK $3.00. A refer- ence book lor all interested in stereo and multichannel sound reproduction. HI BP99— MINI-MATRIX BOARD PROJECTS S5.00. Hsre are 20 useful circuits thai can be buift on a mini-matrix board that is jusl 24 holes by ten copper-foil strips. n BP157— HOW TO WRITE ZX SPECTRUM AND SPECTRUM r GAMES PRO- GRAMS $5.95- A cryslal-clear step-by-slep guide 10 wriling your own graphics games programs. n BP117— PR ACT1CAL ELECTRONIC BUILDING BLOCKS— Book 1 $5.75, Oscillators. Timers, Noise Generators, Rectiliers, Comparators, Triggers and more. D 2t9— SOLID-STATE NOVELTY PROJECTS S4.95. Fun projects include Ihe Optomin. a musical inslrument lhat is played by reflecting a light beam wilh your hand, and many more. □ BPt79— ELECTRONIC CIRCUITS FOR THE COMPUTER CONTROL OF ROBOTS S5.00. Data and circuits for interfcing the computer to the robot's motors and sensors. □ BP126— BASIC & PASCAL IN PARALLEL 54.95. Takes Ihese two program- ming languages and develops programs in both languages slmullaneously. n 224—50 CMOS IC PROJECTS 55.25. Includes sections on mullivibrators. amplifiers and oscillators, trigger devices, and special devices. [~l 225— A PRACTICAL INTRODUCTION TO DIGITAL IC'S 54.95. Mainly con- cerned with TTL devices. Includes several simple projects plus a logic circuit lest set and a digital counter timer. □ BP170— I NTROD UCTtON TO COMPUTER PE Rl P H E RALS $5.95. Shows tow to use a variety of co computer add-ons in as non-technical a way as possible. □ 227— BEGINNERS GUIDE TO BUILDING ELECTRONIC PROJECTS 55.00. How 10 lackle the praclical side of electronics so you can successfully build eleclronic projects. [7i BP168— HOW TO GET YOUR COMPUTER PROGRAMS RUNNING 55.95. Shows how to identify error in program and what to do about them. □ 123— FIRST BOOK OF PRACTICAL ELECTRONIC PROJECTS $3.75. Proj- ects include audio distortion meter, super FET receiver, guilar amplifier, rnel ronome and more. H BP24—52 PROJECTS USING tC 741 55.25. Lots of projecls buill around Ihis one available IC. O BP110— HOW TO GET YOUR ELECTRONIC PROJECTS WORKING $5.00. How lo find and solve Ihe common problems lhat can occur when building projects. ^*w»» **■ Hmeirvrr* Tkn«> ritoti □ BP33— ELECTRONIC CALCULATOR USERS HANDBOOK $5.75. Invaluable book For all calculator owners. Tells how to get the most qui of your calculator. D BP36— 50 CIRCUITS USING GERMANIUM, SILICON & ZENER DI- ODES S5.0D, A collection ol useful circuits you'll want in your library, D BP37— 50 PROJECTS USING RELAYS, SCRS & TRIACS 55.00. Build pri- ority indicators, light modulators, warning devices, light dimmers and more. D BP183—AN INTRODUCTION TO CP/M S5.75. To run and use programs oper- ating under the CP/M operating system you will find this book extremely useful. □ BP42— SIMPLE LED CIRCUITS S5.00. A large selection of simple applications for Ihis simple electronic component. U BP127— HOW TO DESIGN ELECTRONIC PROJECTS $5.75. Helps Ihe reade* to put projects together from standard circuit blocks with a minimum of trial and error. I~l SP122— AUDIO AMPLIFIER CONSTRUCTION $5.75. Conslruclion delails for preamps and power ampliliers up through a 10D-waH DC-coupled FED amplifier. D BP92—CRVSTAL SET CONSTRUCTION $5.00. Everything you need lo know about building crystal radio receivers. O BP4S—PROJECTS IN OPTOELECTRONICS SS.DO, Includes infra-red detec^ tors, transmitters, modulated tight transmission and photographic applications. n BPia— ELECTRONIC PROJECTS FOR BEGINNERS $5.00. A wide range ol easily completed projects lor the beginner. Includes some no-soldering projects. H BP49— POPULAR ELECTRONIC PROJECTS $5.50, Radio, audio, household and lest equipment projecls are all included. □ BP51— ELECTRONIC MUSIC AND CREATIVE TAPE RECORDING $5.50. Shows how you can make eleclronic music al home with Ihe simplest and mosi inexpensive equipment, \J SPSS— ELECTRONIC SECURITY DEVICES $5.00. Includes both simple and more sophisticated burglar alarm circuits using light, infra-red, and ultrasonics. n BP59— SECOND BOOK OF CMOS IC PROJECTS S5.00. Moredftuils show- ing CMOS applications. Most are of a fairly simple design. □ BP72— A MICROPROCESSOR PRIMER $5.00. We starl by designing a smalt computer and show how we can overcome its shortcomings. □ BP74— ELECTRONIC MUSIC PROJECTS $595. Provides the experimenter wilh a variety of practical circuits including a Fuzz Box, Sustain Unit, Reverberation Unit, Tremelo Generator and more. G BP91— AN INTRODUCTION TO RADIO DXING $5.00. How you can tune in on those amaleur and commercial broadcasts from around the world in the comfort ol your home. C BP94— ELECTRONIC PROJECTS FOR CARS AND BOATS $5.00. Fifteen simple projects that you can use with your car or boat. All are designed to operate from 12-vol! DC supplies. m A ELECTRONIC TECHNOLOGY TODAY INC. PO. Box 240, Massapequa Park, NY 11762-0240 Name . Address City .Stale . .Zip. SHIPPING CHARGES IN USA S CANADA $0.01 to $5 CO 55.01 U £10.00 $10.01 10 20.00 $20.01 10 30.00 $30.01 to 40.00 $40.01 to 50.00 S1.00 S1.75 $2.75 $3.75 $4.75 S5.75 R8-87 $50.01 and above. $7.00 ™ E " SA s " N " A , Number of books ordered Q Multiply Shipping by 2 for sea mail Multiply Shipping by 4 tor air mail Tolal price of merchandise $ Sales Tax (New York State Residents only) $ Shipping (see chart) £ All payments must be in U.S. funds Tolal Enclosed . S . 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