TRANSMISSION LINES 



297 



carrier system described in a recent A. I. E. E. paper by A. B. Clark 

 and B. W. Kendall.^ 



The losses in the cable circuits do not, of course, remain absolutely 

 constant with time, and slow variations due to change of temperature 

 are compensated for by occasional adjustments of the variable equal- 

 izer arrangements provided. These adjustments were required only 

 infrequently; approximately at weekly intervals because in an under- 

 ground cable the temperature experiences only slow, seasonal 

 variations. 



As noted, new repeater stations were established at two points. The 

 housing arrangements for one of these points, Abingdon, is shown in 

 Fig. 9. The equipment at this repeater point also included relays 

 remotely controlled from the nearest attended repeater station to 

 permit the repeaters to be turned on and off at will and the power 

 supply, which consisted of storage batteries, to be switched from the 

 regular to the reserve battery or either battery put on charge if 

 required. 



Fig. 9 — Interior and exterior of special intermediate ri-poatcr 

 Abingdon, Md. 



:.Latiou at 



