CHARACTERISTICS OF TOLL TELEPHONE CABLES 327 



Un + ivn = Jn(bi \/z) (8a) 



and primes denote derivatives with respect to b. 



Substituting Zq from (7a) in (6a) and carrying out the algebraic processes 

 involved gives finally 



R-{- iX = 2 Ro C -{- i {-4 p log ks -^ 2 K Xo) 



(9a) 



1,7 



1.6 



1.2 



1.0 



2.5 



3.5 



where 



4p 



b = a ^A IT X p 



Fig. 27 — Values of correction factor, K 

 For 2k = .75 and .50 



4p 





4 XqMi -\- Vi 

 b Ro uq -{- Vo 



Z nik's) 



2 \n+lUn-lVn-l — ■Mn-l^n-l 



2 ■ 2 



Un-1 + V„-l 



(10a) 



and 



/ / /2 ■ /2 



ir 1 I O \^ /'Z.2 2^nW„_l^;„_l — w„_ii;„_i «o + ^0 



-^=1 + 22^(^5) 2 ;— 2 —, > 



i4-i + I'^-i 



4p 



+ ^j:n(k'sr'bg 



2 \n+l7 W„_it;„_i — Un-lVn-1 



62 X 



Wn-l + »n-l 



+ 2ze;n 



Mo + »0 



