258 BEI.L SYSTEM TECHNICAL JOURNAL 



at the junction of the cable and the open wire construction. An 

 incidental cable occurring at a line terminal is ordinarily known as a 

 toll entrance or a terminal cable; when occurring at an intermediate 

 point, it is known as an intermediate cable. 



The reduction of junction impedance irregularities has become 

 especially important during recent years as a result of the rapidly 

 increasing use of telephone repeaters, since in repeatered circuits, 



Fig. 13— Installation of aerial toll cable loading— single pole fixture for small branch 



cables 



line impedance irregularities, by virtue of their effect upon the re- 

 peater circuit balance, may reduce the effective repeater gain and 

 thereby impair transmission by an amount much larger than the 

 ordinary reflection loss. Prior to the general use of telephone re- 

 peaters, satisfactory results w^ere obtained by using some one of the 

 standard heavy or medium weight cable loading systems on the 

 entrance and intermediate cables associated with loaded open wire 

 lines, and a special weight of loading was used on the incidental 

 cables in the non-loaded open wire lines. In some cases ordinary 

 medium loading was used, wdth suitable types of step-up or step- 

 down transformers at the terminals of the inserted cable. 



Incidental Cables in Loaded Open Wire Lines. In toll entrance 

 and intermediate cables associated with loaded open wire lines, the 



