Precision gain and phase matching of low-noise traveling-wave amplifiers

A highly-refined group of low-noise traveling-wave amplifiers has been developed for use in a monopulse tracking system for the Apollo program. A total of 36 amplifiers must gain and phase track each other across a wide frequency band and over wide temperature ranges while maintaining an extremely low noise figure. This was accomplished by building tubes permitting final gain and phase adjustments to be made external to the vacuum envelope and by using a very stable and well-regulated power-supply.