354 



BELL SYSTEM TECHNICAL JOURNAL 



The use of non-loaded paper insulated pairs in existing entrance 

 cables has been mentioned. However, it is in general not practicable 

 for crosstalk reasons to use all the non-loaded pairs which are available 

 in one cable, and the selection of pairs suitable for type J operation is 

 illustrated by a discussion of the methods used on the Dallas cable. 



FILTER HUT 



LEGEND 



P I = PAPER INSULATED 

 SP 4 = SPIRAL FOUR 

 TERM= CABLE TERMINAL 

 t )' CABLE 



EXISTING .,. 



SHIELDED— <=ttt= 

 CABLE 



Fig. 10- — Circuit connections through Austin. 



The Dallas cable is composed of three sections of different make-up. 

 The section nearest the central ofhce, 1.3 miles long, and the inter- 

 mediate section, 1.6 miles long, each contained 22 idle non-loaded pairs, 

 and the third section, one mile long, had only six. The Houston line 



