AMPLITUDE RANGE CONTROL 



527 



obtained by multiplying the original wave by a factor which is inversely 

 proportional to the rectified envelope. For comparison, the original 

 wave is shown in Fig. 5a, and the result of instantaneous compression 



2 20 



5 40 



< 30 



10 20 30 40 50 60 70 80 90 100 



PER CENT OF TIME EMF IS ETQUAL TO OR LESS THAN EMF SHOWN 



Fig. 4— The amplitude range of the wave of Fig. 3 is infinite on a db scale but most 

 of the values are bunched in a much smaller range. 



by the same control ratio in Fig. 55. It is assumed that the arbitrary 

 reference voltage which is not changed by compression corresponds to 

 the maximum value of the input wave, although any other value 

 might be used instead. It is evident from Fig. 5 that envelope com- 



