APPLYING CARRIER TELEPHONE SYSTEMS 



571 



OUTPUT SEALED TEST- 

 TERMINAL BAYS 



TO 

 PROTECTORS 



X X 



LINE 

 JACKS 

 i X X 



BY- PASS 

 SETS 



-(iffl: 



•\ TO TOLL 

 .(CABLE A 



CARRIER 

 CIRCUITS VOICE- 

 FREQUENCY 

 CIRCUITS 



^^ 



CONTROLLERS 



FLAT GAIN 



1 HIGH- I r 

 I FREQ. I 

 I JACKS I 



AMPLIFIER EQUIPMENT 



I 



I I 



AMPLI- 

 FIER 





AMPLI- 

 _FIER_j 



USED ONLY FOR 

 PILOT WIRES 



BY- PASS 

 SETS 



' X X 



LINE 

 JACKS 



X X 



BAL- 

 ANCING 

 COILS 



CARRIER 

 CIRCUITS 



AMPLIFIER CABLE 

 DEVIATION DEVIATION ' 



EQUALIZERS 



INPUT SEALED TEST- 

 TERMINAL BAYS 



I 



VOICE- 

 FREQUENCY 

 CIRCUITS 



FROM' 



TOLL 



CABLE B 



TO 

 PROTECTORS 



Fig. 9 — -Continued from page 570. 



In general, these offices are attended regularly by maintenance forces. 

 They serve in some cases as control or supervisory points for the 

 auxiliary repeater stations. Since the installations at main stations 

 have been made in existing voice frequency repeater offices, the avail- 

 able power plant is used to furnish filament and plate current for the 

 amplifier equipment. 



The input and output sealed test terminal bays with a high-fre- 

 quency transmission measuring bay have been installed adjacent to 

 each other to form a five-bay unit for testing and patching purposes. 



Line amplifiers for each direction of transmission have been grouped 

 together in adjacent relay rack bays. Each bay has a capacity of 20 

 amplifiers, except the first, in which is mounted the test amplifier as- 

 sociated with the high-frequency measuring system and 19 line ampli- 

 fiers. Associated with the line amplifiers are the flat gain master 

 controllers and power supply and cable balancing equipment. A 

 schematic arrangement of circuits in a flat gain repeater office is 

 shown in Fig. 15. 



Repeater offices giving both flat and twist gain regulation have been 



