One-Kilowatt Tetrode for UHF Transmitters

A forced-aircooled power tetrode capable of delivering 1,200 watts output in television service at frequencies up to 900 mc is described. Particular features of the design include a coaxial electrode structure, novel metal-to-ceramic seals, and a unipotential matdx-type cathode having a 120-volt heater. A discussion is included of the special parts-making techniques and precision assembly methods in which radio-frequency heating is used together with accurate jigging to maintain uniform electrode spacings. A typical 900-mc circuit for use with the tube is described and tube performance data as a cathode-driven amplifier are given.