HF transmitters and receivers for naval radio

When considering the history of 100 years of radio it should be remembered that some of the first applications were aboard naval vessels. The Marconi Company has been involved with naval communications systems for nearly a century since the early pioneering work of its founder, Guglielmo Marconi. To meet the ever increasing user requirements, technology has advanced through the generations of Integrated Communication Systems (ICS1, 2 and 3), to the digitally implemented receivers and transmitter drives. The use of wireless receivers and Bellini-Tosi loop antennas for direction finding had been developed by the Marconi Company before the war and by 1916, secret chains of DF stations were in use tracking Zeppelins, submarines and surface craft. 1916 also saw the first valve transmitter tests between aircraft and HMS Calliope, a light cruiser. Seventy five ships were subsequently fitted with valve receivers. In the 1960s, the UK MOD working with UK industry, embarked upon a programme of work under the title "Integrated Communications Systems for Ships". This subsequently developed from Stage 1 to Stage 3 (ICS3). The transmit antenna problems were overcome by using broadband HF antennas incorporating parts of the ship structure, e.g. masts and funnels.