AMPLITUDE CHARACTERISTICS OF TELEPHONIC SIGNALS 541 



BIASED 

 CONTROL 

 CIRCUIT 



VARIC- 

 LOSSER 



GAIN 

 INCREASER 



GAIN 

 DECREA5ER 



BIASED 

 CONTROL 

 CIRCUIT 



GAIN INCREASE DIS- 



ABLER (BLOCKS 

 INCREASER ACTION) 



VOGAD 



BIASED 

 CONTROL 

 CIRCUIT 



VARIO- 

 LOSSER 



:zi 



GAIN ' 

 INCREASER 



A. 



GAIN INCREASE 

 DISABLER 



GAIN DE-< 

 CREASER 



BIASED 

 CONTROL 

 CIRCUIT 



VARIO- 

 LOSSER 



HALF VOGAD 



TIME FUNCTIONS SAME 

 AS VOGAD 



GAIN CHANGES HALF 

 AS GREAT 



VOLUME LIMITER - 

 FIGURE 3 



REGULATING 

 THRESHOLD 



COMPRESSOR 



\ 



EXPANDOR 



n. 



