Low-, medium-and high-frequency communication to and from H.M. Ships

The five-year period preceding the war was one of great activity in the field of naval communications. The separation aboard ship of transmitting and receiving offices and aerials, the development of common power supply and control systems and of new ranges of transmitters and receivers, were parts of a large-scale effort to modernize the communication equipment used by the Navy and to make possible simultaneous transmission and reception in ships. Increasing shore station, particularly ship-shore, traffic, and a more accurate knowledge of propagation phenomena, led to an extensive modernization of shore station equipment and improvements in procedure. As a result of this effort, ships of the Fleets were, at the outbreak of war, well equipped and well manned to carry out long-distance or Fleet communications. The early war years were a period of rapid naval expansion, particularly in connection with auxiliary craft, escort vessels, armed merchant cruisers and co-operation with aircraft. This necessitated the wide use of medium-power radiotelephony transmitters and receivers, and the training of large numbers of operators and mechanics skilled in the use and maintenance of these equipments. These r.t. services were provided by existing types of commercial, and later of American naval, equipments. Meanwhile, at the A.S.E., efforts were devoted to the improvement of the frequency stability of transmitters; the reduction of interference aboard ship; the improvement of ships´ aerial arrangements, particularly in so far as these were affected by the increased communication requirements, the large-scale use of radar and of anti-aircraft armament; and arrangements for improved maintenance in all classes of H.M. Ships. During the later stages of the war, a new range of communication transmitters and receivers was developed to embody the lessons of the war. These sets are now being fitted and are undergoing trials at sea. The paper concludes with a short statement on develop- ments which are envisaged for the immediate future.