A 4 KMC satellite TWT for the AT&T communication satellite

This TWT was especially developed for the service in a satellite repeater. The application necessitated heavy emphasis on high efficiency, long life, reliability, and ruggedness for launch. An overall efficiency of 31% is achieved with an electronic efficiency which exceeds 36% and a ruggedized heater that requires about 1.5 watts. The collector is depressed to less than half the helix voltage. The tube is designed for a life in excess of 10 years and every precaution is taken to make it extremely reliable. The focusing structure is a "Single Reversal Magnet". This new method reduces the weight of the PM material by more than a factor of four over a straight field magnet, yet it retains its excellence of focusing. Although it is heavier than the PPM circuit, it requires much fewer critical machined parts. Beam transmission of better than 99% have been measured with full power output.