648 



BELL SYSTEM TECHNICAL JOURNAL 



The data indicate that if only one of the seven groups of 200-ft. explor- 

 ing wires had been used, the maximum deviation of any one point from 

 the corresponding point on the average curve would have been less than 

 25 per cent and that the probable deviation would have been less than 

 10 per cent. This deviation could probably be reduced by using a 

 somewhat longer exploring wire. 



O 

 O 



a. 



UJ 

 Q. 



0.1 



0.07 



0.05 

 0.04 



0.03 



0.02 



0.01 



0.007 



U 0.005 



< 0.004 



H 

 O 



< 0.003 



o 0.002 



z 



< 



UJ 



o 



< 0.001 



11 



<n 0.0007 



UJ 



_i 0.0005 

 D 0.0004 



0.0003 



0.0002 



0.0001 



10 



20 



30 



50 



100 200 300 500 1000 



HORIZONTAL SEPARATION IN FEET 



2000 3000 5000 



Fig. 18 — Massillon tests. Experimental values of mutual resistance and reactance. 



Measurements were also made of the voltage induced in sections of 

 the telephone line when the power line was energized with ground- 

 return current. A comparison of the measured values of the mutual 

 impedance and those given from calculations using the coupling curves 

 of Fig. 1 8 are given in Table III. With the exception of the section from 

 pole 5134 to 5211, for which the calculations may be subject to some 



