ULTRA-SHORT WAVE PROPAGATION 



133 



the free space value. At 69 mc. the best paths, 8 and 9, gave values 

 which were 15 and 13 db below the inverse distance amplitude. The 

 former gave 32 db at 17 mc. and the latter gave 28 db at 34 mc. In 

 general, the highest frequency showed the smallest attenuation over 

 land. 



LEBANON 



NEW EGYPT 



CHESILHURST 



Fig. 6— Profiles of typical overland paths: A, path No. 8, over hilly country, 

 with receiving location not masked by nearby hills; B, paths Nos. 16 and 17, over 

 level country. 



Fig. 7 — Table of data taken with transmitter at Deal. 



It should be pointed out that these measurements are not inde- 

 pendent of the local receiving conditions. The proximity of the ground 

 has the effect of making the vertical directive characteristic far 

 different from that of the same antenna in free space. In all cases the 

 held increased as the receiving antenna was raised up to the maximum 



