Radio Extension of the Telephone System to 

 Ships at Sea 1 



By H. W. NICHOLS and LLOYD ESPENSCHIED 



Synopsis: The paper describes the development of a two-way radio- 

 telephone system and its use in extending the Bell Telephone System to con- 

 nect with ships at sea. The electrical considerations and the experimental 

 work invoked in determining the system-design of the radio link are dis- 

 cussed. Two land stations were established, one of them a permanent 

 three-channel station on the New Jersey coast. Two coastal vessels and 

 finally one trans- Atlantic liner were equipped. These installations are 

 briefly described in the paper. 



The operation of the combined radio and wire system is explained, par- 

 ticularly in respect to the transmission characteristics of the over-all system 

 and the effect thereupon of the movement of the vessel and of variations in 

 atmospheric conditions. Measurements of the variations in the field strength 

 received from field vessels at sea show why it is possible to receive over very 

 long distances at favorable times at night and not during the day. The 

 method of establishing combined radio-telephone-wire circuits to ships is de- 

 scribed and representative results are given of the considerable telephone 

 traffic which was handled over the system experimentally during a period of 

 trial operation. Tests of multi-channel telephone operation to several ships 

 through the Deal Beach shore station, and also tests of simultaneous tele- 

 graph and telephone operation from the same vessel are described. Con- 

 nection of a vessel thru the transcontinental telephone line to the Catalina 

 Island radio-telephone system, whereby the vessel in the Atlantic talked 

 with an island in the Pacific, is briefly described, and finally the outstand- 

 ing conclusions of the entire development work are given. 



IN 1919, the American Telephone and Telegraph Company and 

 the Western Electric Company initiated a development pro- 

 gram which had for its object the development of a radio telephone 

 system capable of enabling the service of the Bell Telephone System 

 to be extended to include vessels at sea. The program involved 

 extensive development work in the laboratory and field, the establish- 

 ment of shore and ship stations, and the putting of the system into 

 practical operation, altho on a limited and experimental scale. 



It is the purpose of this paper to describe the results of this develop- 

 ment work from the standpoint of the complete system, with emphasis 

 upon the general transmission and operating features rather than 

 upon the details of the apparatus developed to perform the necessary 

 functions. The development divides itself, naturally, into two parts: 

 first, the determination of the system-design and the establishment 

 of the necessary stations, and, second, the study of the transmission 

 and operating characteristics of the system. 



1 Presented before The Institute of Radio Engineers, New York, January 3, 1923, 

 Reprinted with minor changes from the Procd. of Institute of Radio Engineeis, 

 June, 1923. 



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