SELECTIVE FADING OF SUPER-HIGH FREQUENCY SIGNALS 1193 



10 



20 



_j 40 

 < 



a. 



o 50 



< 



o 

 o 



5 10 



o 

 a. 



it 20 

 if) 



5 30 

 o 



b 10 



20 



30 



50 



3800 3900 4000 4100 4200 



FREQUENCY IN MEGACYCLES PER SECOND 



Fig. 3 — Typical path-loss versus frequencj^ curves observed on the Princeton- 

 Lowden, Iowa, path during July and August, 1950. 



by relatively small components such as components 5 and 6. In the case 

 of deeper fades much smaller components may be of importance in 

 determining the shapes of the curves near maxima of path loss; hence the 

 curves for deep fades are quite difficult to synthesize. The shape near the 

 maximum of path-loss on the curve in Fig. 2(a) is quite typical of the 

 shapes to be found in the data under discussion. 



Based on the experience gained in attempting to synthesize some of 

 the cur\^es, it is possible to recognize the significance of certain features 

 of other curves, and to generalize the nature of all the curves. The prin- 

 cipal conclusions are: 



1. No deep fades were found which did not show definite frequency 



