242F-9 50 watt VHF UHF AM Transmitter

Developed in the 60s for the commercial and military aircraft ground communication market, this transmitter is reputedly the design team’s nemesis. The quality is serious Collins and it features a cavity tuned PA using a 4CX250B that covers both the VHF (108-152 mHz) and the UHF (200-400 mHz) aircraft bands.  Now for those of you that are at all familiar with cavity amplifier design, building a cavity that will tune 3 octaves is a monstrous job. Collins accomplished this with a gold plated Swiss Watch design that actually has a gear shift and is an electrical mechanical marvel. This transmitter was also designed for 24/7 operation and its reliability prompted its use in VOR ground station applications requiring 100% duty cycle. This particular unit was installed in the Lockheed Skunk works on the California desert and heard a lot of SR-71 chatter come through its pipes.