CROSSTALK AND NOISE FEATURES 161 



impedance of one of these coils, and the approximate suppression which 

 a set of them provides, are shown in Fig. 18. 



In addition, the carrier circuits are carefully separated, electrically 

 and physically, from existing voice frequency circuits in common re- 

 peater stations. To this end the carrier pairs in the outside cable are 

 brought out on the line side of the noise suppression coils into a separate 

 cable connected directly to a sealed terminal. From this terminal 

 they are carried in shielded wire to the units in the carrier ofEce and 

 then to a similar sealed terminal leading to the outside cable in the 

 opposite direction. Filters for filament and plate battery supply are 

 included in the carrier amplifiers and additional filament battery 

 supply filters are provided at the carrier fuse panels. 



