AMPLITUDE CHARACTERISTICS OF TELEPHONIC SIGNALS 543 



VARIO- 

 LOSSER 



VOLTAGE = 

 ■INPUT VOLTAGE 



CONTROL 

 CIRCUIT 



INPUT 5 



CL 



LIMITED RANGE EXPANDOR ? 

 RADIO NOISE REDUCER 

 FIGURE 6 



AMPLITUDE 

 ^X- A 



AMPLI- 

 TUDE B 



PEAK CHOPPER - 

 FIGURE 9 



AMPLITUDE 



BIASED 



CONTROL^ 



CIRCUIT 



VARIO- 



LOSSER 



TWO VALUES 



OF LOSS 



--— Q. 



CROSS-TALK SUPPRESSOR 



AMPLITUDE 



