Radiotelephone System for Harbor and Coastal Services

Radiotelephone service with harbor and coastal vessels is now being given through coastal stations in the vicinities of seven large harbors on the Atlantic and Pacific coasts with additional stations planned. The system is designed to be as simple as possible from both the technical and operating standpoints on both ship and shore. Recent developments in the shore-station design eliminates all manipulations of the controls by the technical operator. This is made possible principally because of crystal-controlled frequencies on shore and ship, a "vogad" which keeps the transmitting volume of the shore subscriber constant, and a "codan" incorporated in the shore radio receiver which will operate on signal carrier but is highly discriminatory against noise. A signaling system permits the traffic operator to call in an individual boat by dialing the assigned code which rings a bell on the particular boat called. The ship calls the shore station by turning on the transmitter. The radio signal operates the codan in the shore receiver which in turn lights a signal lamp in the traffic switchboard. Gradually the system has been taking on more and more the aspects of the wire telephone system.