18 



BELL SYSTEM TECHNICAL JOURNAL 



90" 

 60" 

 30' 





 10 f-KC 20 10 f-KC 



Fig. 21 — Envelope transmission through tuned circuit. 



20 



AUXILIARY 

 FILTER 



Fig. 22 — Special .\-V-C oscillator. 



60 



40 

 Adb 



20 



0.1 



120 



80 



r 



40 



10 100 1,000 10,000 100,000 1,000,000 

 f-'^/SEC. 



Fig. li — Characteristics of au.xiliarv filter. 



