TRANSATLANTIC RADIO TELEPHONY 



323 



connecting to a discrete terminal which is the real ground. As is 

 shown in Fig. 6a, the actual wave-antenna may still be considered as 

 a smooth line, but between the terminals of the wave-antenna and the 

 terminals that are available at the physical ends of the wave-antenna 

 ground-connection impedances exist. To determine the constants of 

 the wave-antenna, these impedances must be evaluated and taken into 

 account as follows: In Fig. 6a, an impedance Z is applied to the avail- 



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2 G, 6 



SMOOTH LINE 

 WITH CONSTANTS 

 K,7 



(a) 



(M 



(c) 

 Fig. 6. 



able terminals of the wave antenna 3-4 and the impedance 5 measured 

 at the available terminals 1-2 ; under this condition, the actual terminal 

 and input impedances of the wave-antenna are respectively: 



Z' = Z + G2 

 S' = S - Gi 



(1) 

 (2) 



where Gi and G2 are the ground-connection impedances at the two 

 ends of the antenna. 



Figs. 6b and 6c illustrate the method that was used to determine 

 the ground-connection impedance. In Fig. 6b, lines 1 and 2 represent 

 two smooth ground-return transmission lines extending in opposite 

 directions from the ground connection for )4 kilometer 01 more, the 

 lines being terminated at the distant end in impedances Z/ and Z2', 

 respectively. In practice one of these lines was the wave-antenna 



