RADIO TELEPHONE SERVICE TO SHIPS AT SEA 425 



The subscriber's booth is provided with a desk telephone set having a 

 high-grade transmitter. The outgoing and incoming circuits are 

 shielded from each other and brought separately to the transmitter and 

 receiver of the subscriber's set. An illustration of the subscriber's 

 booth on the Leviathan is shown in Fig. 15. 



Fig. 15 — Subscriber's booth on Leviathan. 



The Wavelength Situation and Simultaneous Telephone 



AND Telegraph Operation 



Communication between ship and shore is carried out by the use of a 

 pair of frequencies, one for transmission in each of the two directions, 

 separated from each other by about 3 per cent. The specific frequen- 

 cies which were first assigned by the Federal Radio Commission to the 

 shore station and the Leviathan were necessarily chosen on more or less 



