Development of a 400 watt 8.0-12.4 GHz traveling wave tube for airborne ECM applications

Prior to the development of the Sperry STX-54400, the state-of-the-art for PPM focused, conduction cooled, airborne X-band helix TWT´s was approximately 200 watts. Through the use of improved heat transfer techniques including improved depressed collector and output window designs, the state-of-the-art was advanced to the 400 watt level. This paper discusses the novel design features, solution of some of the problems encountered, construction details, and performance.