TRANSATLANTIC RADIO TELEPHONY 



333 



It is seen that the agreement between the measured and the com- 

 puted directional characteristic is much better for the shortened Houl- 

 ton A antenna than it is for the same antenna 0.70 kilometer longer. 



> 0,8 



I- 



Q. 



SO.7 

 liJ 

 a. 



0.6 

 < 



O 0.5 

 I- 

 o 

 ^0.4 



Q 

 0.3 



UJ 



> 



1^0.2 



_i 



Ct 0.1 



10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 



360 350 340 330 320 310 300 290 280 270 260 250 240 230 220 210 200 190 180 



ANGLES OF INCIDENCE (e) — DEGREES 



Fig. 8c — Relative Directional Receptivity of Wroughton, England — South Antenna 



HORIZONTAL EFFECT ONLY 



COMPUTED DIRECTIONAL CHARACTERISTIC 



LENGTH = 5.23 KM. 



HEIGHT ABOVE GROUND = 0.0064 KM. 



ANTENNA DIRECTION = N 78" 13' W 



FREQUENCY = 60 KC 



CHARACTERISTIC IMPEDANCE = 399.7 — J 174 OHMS 



ATTENUATION =0.48 TU PER KM. 



VELOCITY RATIO = 0.922 



EFFECTIVE HEIGHT = 0.0917 KM. 



10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 



360 350 340 330 320 310 300 290 280 270 260 250 240 230 220 210 200 190 180 



ANGLES OF INCIDENCE (6) — DEGREES 



Fig. Sd — Relative Directional Receptivity of Cupar, Scotland — Antenna No. 1 



The reason for this can be appreciated by reference to Fig. 7, where it 

 is shown that the far end of the long antenna is at the top of a rocky 

 hill; while after shortening, the far end is in a swamp, at the same 



