 | |
| Media type | Magnetic tape |
|---|---|
| Encoding | NTSC,PAL |
| Read mechanism | Helical scan |
| Write mechanism | Helical scan[1] |
| Developed by | Ampex |
| Usage | Video production |
| Released | 1965 (1965) |
1-inch Type A Helical Scan orSMPTE A is areel-to-reelhelical scananalog recordingvideotape format developed byAmpex in 1965, that was one of the first standardizedreel-to-reelmagnetic tape formats in the 1-inch (25 mm) width; most others of that size at that time were proprietary. It was capable of 350 lines.[2]
Type A was developed as mainly an industrial and institutional format, where it saw the most success. It was not widely used forbroadcast television, since it did not meetFederal Communications Commission (FCC) specifications for broadcast videotape formats; the only format passing the FCC's muster at the time was the then-industry-standard2-inch quadruplex.
The Type A format received broad use by theWhite House Communications Agency from 1966 to 1969. The WHCA, under U.S. PresidentLyndon B. Johnson, used the format to videotape television broadcasts off the air or from direct White House feeds.[3] The WHCA recorded programs and events including television appearances by President Johnson, special news broadcasts and news interview programs. Beginning on April 1, 1968, the WHCA taping system was expanded to also include daily morning and evening news programs, both network and local. When U.S. PresidentRichard M. Nixon succeeded Johnson in office in 1969, the WHCA's Type A recording system was continued until it was gradually phased out, later that year, in favor of a recording system using a 2-inch format.[4]
The format was also used by theVanderbilt Television News Archive atVanderbilt University in Nashville, Tennessee, upon the archive's founding in 1968. The archive would continue to use the Type A format to make black & white recordings of national television newscasts (received off-air, and recorded by the archive, from the local Nashville network-affiliated TV stations that aired them) until 1979, when the archive upgraded to full-color-capableU-Matic VCRs for recording.
Early VTRs wereblack-and-white (B/W) only, later VTRs supportedcolor television, with aheterodyne playback. Still later units hadtime base correction playback, like the VPR-1 that could be used attelevision station andpost-production houses.
The VPR-1 had several problems, it did not record thevertical blanking interval (as the format in general was not capable of), which is why it was not compliant to FCC broadcast standards. Thevideo quality was not as good as other broadcast VTRs. ThusSony and Ampex agreed to make a SMPTE approved typeC format VTR (which was based on Type A).Hitachi also later made a C format VTR.
