THE VODAS 



469 



"six" over a telephone circuit transmitting a band of frequencies 

 from about 800 to 2000 cycles per second, which is the range normally 

 effective in operating the vodas. The upper trace shows the point at 



60 



52 



</) 



48 



Z 



o 

 (J 



uj 44 



36 



32 





 Z 28 



Z 



20 



9. 16 



-12 



-26 -24 -22 -20 -18 -16 -14 -12 -10 -8 -6 -4 -2 



INPUT IN DECIBELS (RELATIVE TO I MILLIWATT) 



Fig. 8 — Operation on a 5-C.P.S. sine wave. 



which the syllabic Type B device operated and the lower trace shows 

 the point at which the Type A device operated. Since the speech 

 wave shown was used to operate both devices, the reduction of clipping 



