TRANSMISSION LINES FOR RADIO SYSTEMS 



417 



The results of these measurements appear on F'ig. 2. The solid 

 curves were computed by means of (3), neglecting the conductance 

 term. The points are the experimental observations. Note that, ex- 

 cepting lines G and //, the small margin between measured and calcu- 

 lated values shows that the leakage losses are very small. It is believed 

 that the scattering of the observed points could have been reduced 

 appreciably if corrections for variations of resistivity with temperature 

 had been made. 



100 

 80 



60 

 40 



2 4 6 8 10 



FREQUENCY IN MEGACYCLES 



Fig. 2 — Radio-frequency resistance measurements upon concentric tube lines. 

 The curves are based upon computations and the points are experimental observa- 

 tions. See Fig. 1 for line details. 



In lines B, E, and H the sheath and the inner conductor comprised 

 materials of different resistivities. Calculations for these cases were 

 made with the assistance of a modified form of (3) : 



a 



(3a) 



in which the subscripts denote the inner and the outer conductors. 



