94 



BELL SYSTEM TECHNICAL JOURNAL 



500 

 400 

 300 



UJ 



d 200 





 -100 

 -200 

 -300 

 -400 

 -500 

 -600 



30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 

 PLATE VOLTAGE 



(a) 



600 

 500 



400 



300 



200 



100 







-100 



-200 



-300 



FILAMENT CURRENT IN AMPERES 



(b) 



Fig. 21 — Performance of reversed feed-back oscillator with loose coupling, grid 



stabilization. 



(a) Variation of frequency with plate potential. 



(b) Variation of frequency with filament current. 



