86 BELL SYSTEM TECHNICAL JOURNAL 



connected to a No. 16 two-wire circuit with a two-wire repeater at 

 Bedford. This arrangement was used in order to start service through 

 the cable with the facilities available, but it is intended later on to use 

 the arrangement shown in example No. 2. 



In example No. 2, No. 16 heavily loaded conductors are used and 

 two-wire repeaters are located at Reading, Shippensburg and Ligonier. 

 The total transmission equivalent of this circuit without repeaters is 



PITTSBUnCH LICONIER BCOrORD SHIPPCNSBURC HtRRISBURC READING PHILIDCLPHI* 



1\ 



pnr^^w^g -g—*! 



Philadelphia- Pittsburgh Circuit Initial Arrangement 



-Two -Wire Telephone Repeater 



Philadelphia- Pittsburgh Circuit Proposed Arrangement 



/I6 4WG Heavy Loaded Two - Wire Circuit H Telephone Repealer tlement 



/I9AWG Medium Loaded Four-Wire Circuit Q Balancing Network 



Fig. 30 — Cable Circuit Arrangements 



about 50 miles of standard cable so that in order to obtain a net 

 equivalent of 12 miles for the circuit each of the three repeaters must 

 give a transmission gain of nearly 13 miles of standard cable. This 

 circuit could not of course be used for telephone purposes without 

 repeaters. 



The third example shows how it is expected to operate New York- 

 Pittsburgh circuits intended for business between these two terminals. 



PITTSBURGH BEDFORD HARRISBURS PHILADELPHIA NEW YORK 



New York - Pittsburgh Circuit 



/I9AWG Medium Loaded four-Wire Circuit 



Q Telephone Repeater Element Balancing Netwsrk 



Fig. 31 — Cable Circuit Arrangements 



Four-wire No. 19 loaded cable facilities are used with four-wire tele- 

 phone repeaters located at New York, Philadelphia, Harrisburg, 

 Bedford and Pittsburgh. 



Even with conductors of only two gages in the cable, it is clear that 

 many different combinations of facilities can be built up into tele- 

 phone circuits and an endeavor is always made to use the most eco- 



