Abstracts of Technical Articles from Bell System Sources 



North Atlantic Ship-Shore Radio Telephone Transmission During 

 1930 and 193L^ Clifford N. Anderson. Considerable data on 

 radio transmission were collected during the years 1930 and 1931 in- 

 cidental! to the operation of a ship-shore radio telephone service with 

 several passenger ships operating in the North Atlantic. This paper 

 discusses briefly the results of an analysis of these data. Contour 

 diagrams are given which show the variation of signal fields with dis- 

 tance and time of day for the various seasons on approximate frequen- 

 cies of 4, 9, 13, and 18 megacycles. Similar diagrams show the 

 distributions of commercial circuits. Curves are also shown w^hich 

 enable the data to be applied more generally for other conditions of 

 noise and radiated power. 



Short-Wave Transmission to South America.'^ C. R. Burrows and 

 E. J. Howard. The results of a year's survey of transmission condi- 

 tions between New York and Buenos Aires in the short-wave radio 

 spectrum are presented in this article. Surfaces showing the received 

 field strength as a function of time of day and frequency are given. 

 These show that frequencies between 19 and 23 megacycles were best 

 for daytime transmission, and those between 8 and 10 megacycles for 

 nighttime transmission. A transition frequency was required in the 

 early morning, but the useful periods of the day and night frequencies 

 overlapped in the evening. 



No variations that could definitely be traced to a seasonal effect 

 were found. This path is much less affected by solar disturbances 

 than the transatlantic. 



Frequencies above 30 megacycles appear to have but little commer- 

 cial value over this path. Frequencies a few megacycles higher could 

 not be received. 



The International Telegraph and Radio Conferences of Madrid.'^ L. 

 EsPENSCHiED and L. E. Whittemore. A combined meeting of the 

 International Telegraph and Radio Conferences at Madrid in the fall 

 of 1932 was attended by delegates of government communication 

 administrations and representatives of communication companies from 



' Proc. I. R. E., January, 1933. 



2 Proc. I. R. E., January, 1933. 



■^ Bell Telephone Quarterly, January, 1933. 



244 



