CABLE CARRIER TELEPHONE TERMINALS 



119 



In a type K terminal office transmission tests are made at the four- 

 wire test board shown in Fig. 9, A, where the incoming and outgoing 

 voice-frequency circuits appear, and at the high-frequency test board 

 shown in Fig. 9, B. At the former, four-wire talking, monitoring and 

 testing circuits have been provided for voice-frequency maintenance. 



Fig. 9 — Test positions: "A" — voice frequency; "B" — high frequency. 



Adjustment of the equivalents of the individual channels can be made 

 from this point as previously described. Much can be done from this 

 position by means of monitoring and noise measuring to diagnose 

 troubles. 



At the high-frequency testboard the circuits are brought through 

 jacks and high-frequency measuring apparatus is provided. Measure- 



