Museum Hours:

Saturday 10-6

Sunday 12-5

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.

Here are recollections of William N. Parker, written in 1984. Parker worked for U. A. Sanabria in the late 20s and early 30s.

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.

Two flying-spot scanners were provided, each with a turret of four projection lenses and a steerable surface-reflecting mirror to properly position the scanned field. The low scanner was used for seated persons seated behind a bank of photo-cells built into the wall. The other scanner projected its beam at eye height into the studio. The light sources for the scanners were 30 volt, 30 amp incandescent projection lamps.

Light pickup for the long shots was by means of two large photo-cells suspended from ceiling tracks on either side of the studio. Each one had a separate preamplifier and cable to the main amplifier rack adjacent to the scanners. The main amplifier boosted the picture signal and sent it over a special low capacitance cable to the W9XAP transmitter over 100 feet away. A viewing monitor mounted in the rack permitted convenient checking of the picture. Switching between pickups employed relays, pushbuttons and signal lamps. A special feature automatically blanked out the picture briefly during lens turret operation.

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.

Here are comments by James T. Hawes:

Some of your mechanical TV directory pages list Chicago's WCFL/W9XAA as transmitting 45-line pictures. See...

Of course 45 lines would seem true. After all, U.A. Sanabria was behind the WCFL/W9XAA 1928 Navy Pier telecasts. We know him for his 45-line standard, one of the best due to interlacing.

Yet WCFL/W9XAA was *before* U.A. filed his famous, interlaced scanning patent. During the WCFL/W9XAA years, apparently Sanabria used 48 lines *without* interlacing. Peter Yanczer pointed out this fact to me in 1991. I've since confirmed it, partly by research on your site. (Thanks!) Chicago might still have some 48-line Sanabria equipment. In a city museum basement, a friend spotted a 48-line scanner. He thought that this was an Alexanderson machine. But perhaps it was Sanabria apparatus, a leftover from WCFL. I wish that someone would oil the motors, switch on the scanners and produce a half hour show!

See the last page of this link from your site, column 1 (bottom of the page). This story notes that WCFL/W9XAA is using 48-line pictures. As I recall, Sanabria patented 45-line, interlaced pictures in 1929. Here is a link to my Sanabria and Early Chicago television page, including patent data...


Phototube used at W9XAP in 1930

W9XAP - WMAQ's Experimental Television Station
W9XAP on the Silver Screen
Chicago Television History
Early Chicago Television