Early Television Stations
W9XAP/WMAQ - Chicago
W9XAP broadcast from 1930 to 1933, and was the experimental television station of radio station WMAQ, owned by the Chicago Daily News.
My assignment in the fall of
1929 was to design and build the television equipment for
use at W9XAP, the companion station for the Chicago Daily
News station, WMAQ. It was to be located on the 25th floor
of the Chicago Daily News Building, on 400 West Madison St.
Multiple cameras were to be used to facilitate the
instantaneous scene changes required for smooth programming.
The W9XAP transmitter was designed like a commercial broadcast transmitter with a temperature-controlled quartz crystal to maintain the 2150 kc carrier. Several RF buffer stages amplified the carrier to drive a 1 KW water-cooled output tube. A similar tube was used as a series modulator, but this was later changed to a system using a linear amplifier after the modulator.
A large storage battery on an insulated platform supplied the RF output tube filament. The 4000 vdc supply consisted of two double commutator generators connected in series and mounted on either side of a large dc motor. The antenna was strung between the two flag poles on the roof of the building, just above the transmitter room.
The first official telecast of W9XAP was on August 27, 1930. Receivers were distributed to stores in the Chicago area, including Sears Roebuck. Large crowds assembled to see and hear WMAQ artists perform. The signal was strong but the "ghost images" caused disappointment. It seems that ionized layers 50 to 100 miles up caused the delayed signals, resulting in ghosts. Later, images from W9XAP were received up to 400 miles away.
One interesting sight-only program consisted of election returns on the evening of November 4, 1930. Television programs from W9XAO were regular enough to be listed in the Daily News. In fact, here was a two column photo of Marcella Lally in front of the photo cell bank in the May 7, 1930 issue. She may have been the first TV performer to be seen and heard simultaneously. The play, "The Maker of Dreams," was broadcast on the evening of January 7, 1931, possibly the first sight and sound dramatization broadcast. [On September 11, 1938, GE broadcast "The Queen's Messenger," but it did not include sound.
The transmission of fingerprints for the police commissioner was also considered a success. Even ticker-tape stock quotations, delayed 15 minutes were broadcast. Several programs consisting of cartoons drawn on tape were pulled past the scanner.
Phototube used at W9XAP in 1930
For more information, see Chicago Television History