AN IMPROVED THREE-CHANNEL CARRIER TELEPHONE SYSTEM 63 



Regulation 



At the transmitting terminal each channel is adjusted to the same 

 output level and in the operation of the system it is desirable to restore 

 this equality of levels at each repeater point and at the receiving 

 terminal. In each direction of transmission the line losses at the 

 upper end of the frequency range will be higher than at the lower 



(0 l^ 



I- 

 cr 

 < 



o 

 z 

 < 



50 

 48 

 46 

 44 

 42 

 40 

 38 

 36 

 34- 

 32 

 30 

 28 

 26 

 24 

 22 

 20 

 18 

 16 

 14 



22 



20 



18 



O 



_J 



I2q.<d 



UJU 

 N_J 



'°5o 



u 

 6 (0 



17 18 19 20 21 22 23 24 25 26 27 28 29 

 FREQUENCY - KC 



Fig. 11 — Theory of regulator. 



