THE L3 SYSTEM — DESIGN 



815 



Fig. 17 — Typical auxiliary repeater in concrete block nut. 



3.3 EQUALIZING AND SWITCHING REPEATERS 



3.31 Components 



The equalizing auxiliary and main repeaters use the same general 

 types of transmission equipment as the auxiliary repeater except for the 

 equalizers. They differ principally in the quantity of equalization equip- 

 ment provided and the bay arrangements. Table IV lists a summary of 

 the basic transmission units in each repeater. 



At these repeaters a line amplifier is used as a receiving amplifier to 

 compensate for the previous section of cable. Flat amplifiers are used 

 as transmitting amplifiers and to compensate for the loss introduced 

 by the equalizers. They have a flat gain-frequency characteristic and 

 no provision for pilot control of their gain. Their design is very similar 

 to that of the line amplifier and is covered in the companion amplifier 

 paper.^ 



