MARINE RADIO TELEPHONE SERVICE 



703 



land telephone network, apparatus similar to that provided at the 

 terminals of the transatlantic and high seas ship-to-shore radio tele- 

 phone circuits has been provided. This apparatus includes controls 

 for adjusting the volume of speech into the transmitter from the 

 receiver to the wire lines and the usual voice operated devices (termed 

 "vodas") provided for the suppression of echoes and singing. 



The apparatus mentioned, together with a volume indicator, means 

 for talking, monitoring and signaling, and testing apparatus, is as- 



Fig. 1 — Installation of control unit on fishing trawler. 



sembled on one floor-mounted apparatus bay. This, mounted ad- 

 jacent to the bay containing the receiver and a noise suppression de- 

 vice, constitutes the operating position. This position is continuously 

 attended by a technical operator who adjusts the controls during the 

 progress of each call, guided by indications of the meters provided, to 

 insure the best possible connection under the conditions obtained at 

 the time. Power for the terminal apparatus is supplied by a motor 

 generator set operating from a 110-volt 60-cycle source. 



