The radio communications system, or network infrastructure, is the essential backbone of transmitter-receivers, links, control systems and operators with which the mobile and/or portable radio units communicate. Due to the unlimited variety and complexity of radio systems from small to large, they are more difficult to illustrate than the individual mobile or portable radio terminals. Radio communications system equipment is usually located at strategic, but remote places, often high up and on private property.
Photographs of the operator control consoles or equipment racks at the individual radio stations do not completely illustrate the scale and complexity of large radio systems. A limited number of photos survive of complete systems being run up in the factories before delivery to the final sites which can be positively identified and linked to a specific customer or application. Consequently, only a small selection of Pye radio systems network infrastructure and operator control systems will be shown below.
During the 1950s, 1960s and 1970s Pye Telecommunications was Europe’s largest exporter of radio communications systems and at one time was probably the world leader, as the leading American companies Motorola and General Electric had not at that time fully developed their export markets.
The illustration to the right shows the system installed in 1956 which controled gas flow and maintenance along the 350 miles of the Sui-Karachi gas pipeline, then owned and operated by Sui Gas Transmission Co. Ltd. This was engineered by Pye in collaboration with Ericsson Tele-phones Ltd.
Direct telephone and teleprinter circuits between Karachi and Sui and to three intermediate Headquarters stations were provided, together with telephone service to the Repeater stations and telephone distribution at major stations. The backbone of the system was the V.H.F. multi-channel radio link and carrier equipment which connected Karachi to Sui via the three intermediate Headquarters and the five Repeater stations.
Pye Mobile Radio-telephones were fitted to all maintenance vehicles so that they could be called immediately to any part of the pipe-line. Initial maintenance of the system and training of local staff was also undertaken by Pye engineers, and a complete working organisation was handed over to the Sui Gas Transmission Company.
Pye were later awarded a further contract to provide the communications system for an extension of the gas pipeline to Multan, 200 miles north-east of Sui. The facilities provided on the extension of the system were identical with those available on the Karachi to Sui section with the addition of a "through circuit" from Karachi to Multan, a distance of 550 miles.
Project description to follow
Project description to follow
One part of the nation-wide radio system for the Danish State Police being tested at York Street, Cambridge in 1965
Project description to follow
See full case study for more information.