530 



BELL SYSTEM TECHNICAL JOURNAL 



uniformity of construction and detailed specifications of the equipment 

 with which the minimum net loss to be obtained with new toll cables 

 can be closely predicted. 



Performance Characteristics of Two-Wire Circuits 



Fig. 3 shows, for B and H-88-50 two-wire circuits used exclusively 

 for terminating business, the minimum working net losses for various 

 distances as limited separately by crosstalk, echoes and singing. 

 Of course, the lower the net loss the greater is the tendency toward 

 excessive echoes, crosstalk or possibility of singing. For any given 

 case the most exacting limitation controls the minimum working 

 net loss. 



-J 9 



Q 8 



O 



z 



a: 

 o 

 5 



KILOMETERS 

 400 



800 



\ 



200 



300 



MILES 



400 



Fig. 3 — ^Minlmum working net loss of 19-ga. B and H-88-50 two-wire facilities 

 \ ersus circuit length for terminating business. These apply to cither 50-mile (80 km.) 

 sections of B-88-50 or 45-mile (72 km.) sections of H-88-50, whichever has the more 

 severe limitations. 



