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Mechanical Television

A Short History of Television Station W9XK/W9XUI

By Rick Plummer, broadcast historian

The electrical engineering department at the State University of Iowa (SUI) in Iowa City demonstrated television at an exhibit at the Iowa State Fair in Des Moines on August 28, 1931.  J. L. Potter supervised the project.  At the conclusion of the fair, the television experiment is set up in the communications laboratory in the electrical engineering building at SUI in Iowa City.

On September 10, 1931, a suggested finding of fact is submitted to the Federal Radio Commission for a construction permit for an experimental visual broadcasting station.  Several months later, on November 17th, FRC examiner Elmer W. Pratts recommended that a construction permit be issued to SUI.  On January 8th, 1932, a construction permit is issued for the experimental station.  Construction of the station commenced on January 23rd, 1932 and was completed on April 7th, 1932.  A license was granted and the call W9XK was assigned by the Secretary of Commerce to SUI on May 27th, 1932.

Mechanical Scanning Transmitter Specs:

     Power granted: 100 watts

     Frequency:  2000-2100 KHz, 

     Carrier frequency 2050 KHz 

     Wavelength: 146 meters

     Emission: A3, special

     Antenna height: 23 meters

     Frequency tolerance: 0.03%

     Visual studios and transmitter are located on the ground floor of the electrical engineering building located at the corner of Iowa Avenue and Dubuque Street in Iowa City

Scanning Disc Specs:

     45 holes on 3 spirals.  A 15-rpm driving motor spun the disc. The image was scanned 15 times per second.  A 1000-watt projection lamp and 3 condensing and focusing lens were used as well as 10 banks of photoelectric cells connected in parallel.

 Camera and transmitter

On January 25th, 1933, a combined broadcast from W9XK and WSUI was held at 7:15 pm from room 102 in the electrical engineering building.  A brief lecture on the university was presented which included a violin solo by Irene Ruppert,  a lesson in freehand sketching by Aden Arnold, and a dramatic scene from the play "The First Mrs. Fraser", portrayed by Mrs. Arnold Gillette and Miss Helene Blattner. 

On March 4th, 1933, a 15-minute closed circuit demonstration of the television facility consisting of news flashes from the Daily Iowan was broadcast by editor Frank Jaffe and announced by Carl Menzer, director of WSUI. More than 1000 persons witnessed the demonstration. Here areletters from W9XK to an experimenter.

FromPaul Lindemeyer:

Researching the Daily Iowan suggests U of Iowa's 45-liner W9XK showed only visuals for "children's hour" readings during its last year of operation, 1938-'39. Campus radio WSUI offered stories for the young folks at 7 pm Tuesday and Thursday, joining '9XK for 1/4 hour of tv at 7:15. No subject was given for the tv period. With image quality blurry at best - and sometimes marred by a frustrating venetian-blind effect - the instructional usefulness of mechanical tv must have seemed nil after 7 years of regularly scheduled telecasts (a record unmatched anywhere in the world at the time). But plucky W9XK did not shut down until UI's new 441 line camera/receiver pair was ready in mid 1939.

Early Television

W9XUI

A construction permit was granted to SUI for a high-frequency electronic scanning station operating on 42-56 MHz and 60 to 86 MHz (5 meter band) with an output of 100 watts.  The Call sign W9XUI was granted to the new station on September 29th, 1936.  This transmitter used an electronic scan 441-line 30 frames per second system developed by RCA.  In the fall of 1938, an electronic camera and monitor were in operation, but the electronic system but was not being transmitted over the air.

On June 29, 1939, the last program was broadcast over W9XK and WSUI.

On May 15th, 1941, W9XUI transmitted a closed circuit signal of "A Cup of Coffee" to an electronic receiver in an adjacent room.  Twelve technicians and 9 players were necessary to produce the play.  World War II stopped all television experiments at the university and these experiments were never resumed after the conclusion of the war.  Today, two television stations are licensed to Iowa City: KIIN-12, a satellite station of the Iowa Public Broadcasting Network whose transmitter is located near West Branch, and KWKB-20, a Warner Brothers affiliate whose studio, transmitter, and tower are located just across the road from KIIN.

Early Television

Early Television

Early Television

Pictures courtesy of Rick Plummer

Early Television

Ray C. Kent behind the camera - 1941

Courtesy of Harry Moore

Early Television

E. G. Blackstone writing shorthand for the camera - 1933

Courtesy of Harry Moore

Early Television

 


 
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