1330 THE BELL SYSTEM TECHNICAL JOURNAL, NOVEMBER 1956 



4.0 



4.5 5.0 5.5 6.0 6.5 7.0 7.5 



FREQUENCY IN KILOMEGACYCLES PER SECOND 



Fig. 36 — Maximum power output after fading as a function of frequency for 

 several beam currents; in (a) with the helix voltage adjusted for maximum gain 

 at low-level and in (b) with the helix voltage adjusted for maximum power output. 



