LOCATION or OPENS IN TOLL TELEPHONE CABLES 



35 



But 



whence, substituting, 



Zii-2 = Zoi i 



Zn = 



Zfn 

 tanh Q-i ' 



Zoo 



tanh ^1 + 



Zo\ tanh B-i 



f 



tanh Qx tanh ^2 + 



= Zoi i 



Z/0. 



Z02 

 Zo\ 



tanh (92 + tanh Bi 



Zen 

 Zo\ 



Here, as in the case of the non-transposed cable, even values of 

 hyperbolic functions are chosen and the corresponding odd values of 

 length are calculated. Thus, the impedances of different arrange- 



I Hyperbolic error 



II Capacitance error 

 in Summation of errors 1 and n 



I riyperbolic error 

 H Capacitance error 

 in Summation of errors land 11 



Fig. 4 — Diagram showing the construction of a correction curve for a transposed 

 cable. The fault is assumed to be at point Li. Ordinates are the same as in Fig. 

 2. The lower curves I and II show the two errors which are algebraically added 

 to give the total error. 



Fig. 5— This diagram is similar to Fig. 4 except that the fault at Li is in that 

 group of conductors which enters the measuring office in the inner layer of the 

 transposed cable. 



