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BELL SYSTEM TECHNICAL JOURNAL 



only part of the pairs on a line are designated and transposed for J 

 systems and the remaining pairs are not so transposed, absorption in a J 

 pair can be caused by a nearby non-J pair. Consequently, considera- 

 tion of the crosstalk relations at J frequencies between all of the pairs 



u .4 



FREQUENCY- KtLOCYCLES PER SECOND 



Curves A and B: Side 19/20 and 1/2 respectively, on Alternate Arm line, 104 mil, 



12-inch, 56.7 miles, 90° F. at Mascoutah, 111. 

 Curve A is transposed for voice frequencies. 

 Curve B is transposed for carrier operation up to 30 kc. 

 Curve C is pair 39/40 on K-8-2 line, 104 mil, 8-inch, 68 miles, 50° F. and CS insulation 



between Denmark, S. C. and Rincon, Ga. Transposed for carrier operation up 



to 140 kc. 



Fig. 8 — Attenuation of open-wire pairs of different types. 



on the line cannot be avoided even though some of them will not be 

 used for J systems. 



Figure 8 illustrates the effect of absorption on three different pairs. 

 Curves A and B show the absorption measured over the type J 

 frequency range on a line of the Alternate Arm type. Curve A was 



