236 



THE BELL SYSTEM TECHXICAL JOUHXAL, JAXUAUY 1957 



bands by the use of standard A.T. and T. band-splitting equipment (EB 

 banks). Signalling and telephone equipment are provided to give the 

 required omnibus facilities on one circuit and local-calling facilities on 

 the other. The arrangement of the speaker and printer equipment at 

 Sydney Mines is shown in Fig. 11. 



In the telegraph band a third channel transmits an alarm to the re- 

 mote terminal when the 92-kc pilots incoming from that terminal fail 

 simultaneously. 



Fault Location 



The speed}^ and accurate location of faults in repeatered cables is of 

 very great importance, owing to the number of circuits involved and the 

 difficulty and cost of repairs. The standard dc methods which have been 

 applied in the past to long telegraph cables are, of course, available. The 

 application of these methods is, however, recognized as being rather more 



OMNIBUS PRINTER 



TO NEXT 

 STATION 



DIRECT PRINTER 



OMNIBUS SPEAKER 



- 2 KC y , " M 



0-4 KC ,, 



308- 

 312 KC 



312-552 KC 



,. 264- 

 ♦ > 268 KC 



DCO V V V V ' 



— TO ALARM 



— CIRCUITS 



0-4 KC t^ 



552- , 

 556 KC 1^ 



V 16-20 KC 



16-268 KC 



308- 

 556 KC 



TO 

 "CLARENVILLE 



Fig. 11 — Arrangement of speaker and printer equipment at Sydney Mines. 

 A. Submarine cable terminal equipment. B. Speaker circuit equipment. C. Emer- 

 gencj'-band bank equipment. D. Omnibus speaker telephone. E. Local speaker 

 telephone. F. Printer circuit ecjuipment. G. Three-channel telegraph equipment. 

 H. Printer. 



