Tesla SRV 22 medium wave transmitter

This transmitter was used to provide regional radio broadcast in the medium-wave band. The electronics use semiconductors, only the output stages use two vacuum tubes. The transmitter uses pulse-width modulation which ensures good power efficiency. These transmitters are still regularly used. The safety of the maintenance workers is provided by a system of keys which lock the doors of the cabinets. Only when all the cabinets are locked and the keys are placed in the main lock, the transmitter can be switched on.