TWELVE-CHANNEL OPEN-WIRE CARRIER SYSTEM 



373 



Typical far-end crosstalk measured between 8-inch spaced pairs 11/12 

 and 19/20 on a new J-3 line and on a reconstructed K-8-2 line is shown 

 by Fig. 7. The superiority of the new line with its fewer wires, greater 



KILOCYCLES 



Fig. 7 — Far-end crosstalk between 8-inch spaced pairs 11/12 and 19/20. 



pair separations, better transposition system and smaller irregularities 

 is evident. 



Absorption Effects 



The attenuation of an open-wire pair may be quite unsatisfactory if 

 there are what are known as absorption effects, caused by induction 

 into surrounding circuits such that energy is absorbed in particular 

 frequency bands and the attenuation of the pair increased. These 

 effects, which depend on the transposition arrangements in the 

 circuits, may cause objectionable transmission distortion at critical 

 frequencies unless the transpositions are planned to avoid them. The 

 same arrangements necessary to control crosstalk between J systems 

 will automatically eliminate absorption effects with one exception. If 



