Operation of a Ship-Shore Radiotelephone System

During the past two years, ship-shore radiotelephone service has been available with several of the large transatlantic liners. This service has been fairly reliable over distances up to about halfway across the Atlantic and some measure of service has been available all the way across. This paper reviews the essential physical and operating features of the land and ship terminals employed in giving this service. Problems encountered in establishing and operating this service are discussed, together with measures applied for their solution. The most difficult problems have arisen in connection with adapting the ship terminal for operation under the limited space conditions encountered on shipboard. These conditions impose undesirable proximities between units of equipment and between antennas. The operating plan used in coördinating the establishment of the contacts between ship and shore stations is discussed. Considerable data have been collected during the past two years incidental to the operation of the system. Of interest are the contour diagrams indicating the variation of signal fields with time of day and with distance. The variations of the grades of circuit at various distances obtained as a result of operation are shown. During the first six months of 1931, commercial grades of circuit were obtained in about 85 per cent of the contacts.