PHASE DISTORTION AND PHASE DISTORTION CORRECTION 203 



With regard to the loaded cable, we have similarly the phase angle 

 B{co) of the transfer impedance of the cable of length / miles with 

 load impedance Z and smooth line constants R, L, G and C per mile, 

 given rigorously by 



where 



B{ui) = imag. comp. -cosh~^ 



cosh 75 + Try sinh 75 



(10) 



5 = spacing of load coils in miles, 



7 = V(i? + icoL)(G + «coC), 



k = VcrT7^Z)7(gT^^. 



It has been found, however, that dissipation and the distributed 

 nature of the line constants have no appreciable effect on the phase 



30 



w25 



2 



< 



<20 



_i 

 o 



z 



tu 



< 



I 

 0- 5 



500 1000 1500 2000 2500 3000 3500 4000 



■ FREQUENCY IN CYCLES PER SECOND 



Fig. 6 — Phase distortion correction on 20 mile 19 gauge H-44-25 loaded cable. 



< f < 4000 



variation below 4,000 cycles. Hence, as a close approximation, we 

 may take B(w) for the non-dissipative cable without distributed 

 inductance; i.e., simply, 



where 



5(co) = 2iVsin-i///„ 

 1 



(11) 



/c = 



ttVLoCo 

 N = number of sections, 



Lo is the coil inductance and Co the lumped line capacity per secti on 



