Tesla 4001A

Year of manufacture: 1953/57
Manufacturer: Tesla Prague-Strašnice
Tubes used: 8x 6F32, 2x 6B31, 6BC32, 2x 6L31, 3x 6CC31, 6L50, 6Z31, 1Y32, 25QP20, 2x AZ4
Wave bands: pre-tuned to the 1st or 2nd channel of Czechoslovak TV norm, OIRT intercarrier sound

The first Czechoslovak series-produced TV receiver. It is a "tuned radio frequency" receiver, so it is not possible to switch the channels. It is tuned to a single channel depending on where the receiver was to be sold (1st channel near Prague and Ostrava, 2nd channel near Bratislava). Round picture tube with 25 cm diameter. The frame does not cover the whole surface of the screen - the picture could be enlarged just by replacing the frame with a bigger one. The first series did not have the decorative wooden beams in front of the speaker. After the first series was manufactured, the production was halted and the factory waited until all the receivers were sold because it was not clear whether the customers will actually be interested in the television. At first, the television produced little interest among the customers, mainly because the programme was not attractive. In 1955, the Czechoslovak television got a production truck and broadcast an ice hockey match, which dramatically increased the interest. The TV was also made with a radio receiver, this type was marked 4002A. To enlarge the picture, people could buy a plastic lens that would be positioned in front of the screen. The lens was hollow and when it was filled with water, it worked as a magnifying glass, but the viewing angle was reduced. These TVs were frequently placed in public places, pubs etc. and many people watched the tiny picture together. If anyone had the TV at home, then they would invite their neighbours to watch it. In the end, about 200 000 pieces of 4001A and 4002A were manufactured. They were often modified to a 35 cm rectangular picture tube or the receiver was rebuilt as a superheterodyne which enabled channel switching.