CHARACTERISTICS OF TOLL TELEPHONE CABLES 



315 



20 



70 



Fig. 15- 



30 40 50 60 



PREQUENCY- KILOCYCLES 

 -Temperature variation of attenuation; decibels per degree Fahrenheit per mi'.e 

 vs. frequency — 19 gauge pairs 



.0019 



S .0013 



O .0011 



.0009 



FREQUENCY- CYCLES 



D.C. RESI5TANCE-0HMS PER 1000 FT (SINGLE Wl RE) 

 Fig. 16 — Temperature coefficient of attenuation, a. A = .45o[l + cx{T — 50)] 



The change in attenuation with temperature may be formulated in various 

 ways as a function of its component variables, R, L, G, C, the most obvious 

 way being to take the partial derivatives of one of the equations (9), (10), or 



