The Bell System Technical Journal 



April, 1933 



Ultra-Short Wave Propagation * 



By J. C. SCHELLENG, C. R. BURROWS and E. B. FERRELL 



Part I of this paper first describes a method of measuring attenuation 

 and field strength in the ultra-short wave range. A resume of some of the 

 quantitative experiments carried out in the range between 17 mc. (17 meters) 

 and 80 mc. (3.75 m.) and with distances up to 100 km. is then given. Two 

 cases are included: (1) "Optical" paths over sea-water and (2) "Non- 

 optical" paths over level and hilly country. An outstanding result is 

 that the absolute values of the fields measured were always less than the 

 inverse distance value. Over sea-water, the fields decreased as the fre- 



CORRECTION SLIP FOR ISSUE OF JANUARY, 1933 



Page 36 : Line 4, " two lines and their associated apparatus " 

 should read 

 " impedance of each line and that of its balancing network " 



Page 38: Second paragraph, lines 7-8, "do not balance each other" 

 should read 

 " are not perfectly balanced by their networks " 



ditterent paths may tHerelore have widely amerent optimum irequencies. 

 Thus, among the particular cases mentioned, the lowest optimum values 

 vary from frequencies which are well below the ultra-high frequency range 

 up to 1200 mc. (25 cm.). For other paths the lowest optimum frequency 

 may be still higher. 



Introduction 



WITH the extension of the radio frequency spectrum to higher and 

 higher frequencies have come new problems, both of experi- 

 ment and of theory, which require quantitative study for solution. 



* Presented at New York Mtg. of I. R. E., Nov. 2, 1932. Published in Proc. 

 I. R. E., March, 1933. 



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