Early Television Stations
W6XAO/KTSL/KNXT - Los Angeles
One of the most interesting stories in the history of early television is that of Don Lee Broadcasting. Don Lee was a Cadillac dealer in Los Angeles who entered the broadcasting business in 1926 with the purchase of a radio station. In November, 1930, Don Lee engaged the services of 24-year-old Harry R. Lubcke, B.S., University of California, an electrical engineer, and gave him the title of Director of Television of the Don Lee Broadcasting, and applied for a construction permit for the first television station on the west coast, W6XAO.
In 1931 Lee obtained a license for W6XS, which broadcast on a frequency of 2100-2200 kHz, using a mechanical camera that worked only with film. The picture had 80 lines and 15 frames per second. Since there were few commercially available TV receivers at the time, Lubcke prepared and distributed plans for construction of mechanical receiving sets to many amateurs in the area of Los Angeles. The 80 line picture was transmitted on both W6XS and W6XAO. Here is a letter responding to a viewer of W6XS.
On December 23, 1931, W6XAO went on the air from the eighth-floor transmitter at Seventh and Bixel streets, Los Angeles, at 44 1/2 megacycles, to broadcast one hour daily except Sundays. This was one of the first VHF stations to go on the air in the United States. W6XAO broadcast the same 80 line picture as W6XS.
Here is a description of the station from the book "The Great Television Race" by Joseph H. Udelson:
In the early 30s Lubcke started experimenting with electronic television. By 1932 he had developed a CRT receiver with self synchronization. . Because Los Angeles had both 50 and 60 Hz electric power, and to facilitate use of CRT receivers, synchronizing pulses were included in the video signal.
In 1932 he demonstrated television reception in an airplane.
W2XS and W6AXO broadcast the same 80 line images until 1936, when W6XS went off the air.
On June 4, 1936 W6XAO began a month-long public demonstration of its new system, using 300 lines and 24 frames per second, and in 1937 W6XAO published instructions for building receivers for their signal. It is likely that only a handful were made.
The camera was a mechanical flying spot scanner type. One source describes it having "some sort of sine wave vibrating mirror and a Nipkow disk", while the article by F. Alton Everest describes a camera with a large disk. Only filmed material was telecast. Another article in the Los Angeles Times describes the advances made in television, including at W6XAO.
From the above information, we can conclude that the camera worked as follows: The disk spun at 3600 rpm, or 60 rps. To get the rate of 7200 lines per second (24 fps x 300), 120 holes would be required in the disk. As the article says, the holes were all the same distance from the center of the disk. It is not possible to determine the diameter of the disk from the photo, but since it was driven by a 7 1/2 hp motor it must have been quite large. Assuming a disk diameter of 6 feet, the circumference would have been 226 inches. With 120 holes, the holes would have been been 1.88 inches apart. The article says that the holes were #80, which are .0135 inches in diameter. That would allow about 135 hole diameters in the 1.88 inch space, which would roughly translate into the horizontal resolution of the camera. The article mentions that the resolution was improved by aiming the light through the holes at an angle. The screen shots look like about 150 line resolution.
Peter Yanczer commented on the above:
Actually, the disk would be rotating at 60 times per second, making the speed at the edge about 1150 fps, approaching the speed of sound.
Harry Lubke with monitor equipment (ca 1937)
DuMont and RCA Iconoscope cameras were obtained in late 1938 or early 1939, and the standard was changed to 441 lines and 30 frames per second, in line with the RCA system. In 1941 the station changed to 525 lines, and broadcast through World War Two with a limited schedule to the handful of sets in the area.
An early Don Lee camera
W6XAO claims to have broadcast the first soap opera, on April 15, 1938, called "Vine Street".
W6XYZ claimed that their 1943 remote telecast was the first on the west coast. However, W6XAO was actually first with a live telecast of the Tournament of Roses Parade on January 1, 1940.
Telecast from about 1939. The camera was made by RCA.
Rear view of Don Lee camera (ca 1939)
The caption on this picture reads "The internationally noted theatrical producer Max Reinhardt, is shown as he made his television debut Nov 9 (1939). He is shown with Ann Lee, an actress, when the producer and his company appeared in scenes from "On Human Bondage" telecast from the Thomas S. Lee station, W6XAO, only television station in the west."
California, Magazine of the Pacific, June 1939
Courtesy of Steve Dichter
The postmark is Sept. 25, 1939, and says "Betty Jane Rhodes, First Lady of Television"
The W6XAO antenna with building housing transmitter and studio on Mt. Lee in 1941
Some time after 1942 the station acquired RCA orthicon cameras. The photographs below are stereo slides taken some time between 1943 and 1945:
The orthicon camera in 1945
Marilyn Monroe ?
Courtesy of Richard Diehl
On May 6, 1948, the station was granted full commercial status. On becoming a full commercial operation the station adopted the call letters KTSL-TV. Here is an article about remote pickups done by KTSL. It was acquired by the Columbia Broadcasting System January 1, 1951, and ten months later, the call letters were changed to KNXT to coincide with CBS Radio Station KNX. Here are pictures of KNXT's transmitter facility on Mt. Wilson, probably from the early 50s.
A postcard showing the Don Lee Broadcasting building in 1949
Test pattern from the 50s
Many of the pictures above their captions were generously provided by Steve Dichter. More on Don Lee can be found in the Robert L. Pickering's article titled Eight Years of Television in California. Ed Reitan provided an account the history of Don Lee television. More information is provided in a description of W6AXO in 1942 by Al Germond. More W6XAO pictures from a 1944 book "Get Ready to Sell Television."