Factsheet 1966: ITA Engineering 

4 October 2018 tbs.pm/66563

An important duty of the Independent Television Authority is to plan, build, and operate the nationwide network of transmitting stations which brings ITV programmes to viewers throughout the United Kingdom.

The ITA’s first transmitter went on the air at Croydon on [22nd] September 1955. In 1966 the ITA has 30 transmitters covering about 97 per cent of the population; and plans are in hand to build some 20 more relay stations during approximately the next three years.

Main stations range from the small Fremont Point transmitter on Jersey, with an effective radiated power of 10 kW, to the Black Hill transmitter in Central Scotland, with a maximum of 475 kW. The coverage of stations is extended by a number of relay stations which pick up the transmissions and re-broadcast them on other channels. Most of these relays are automatically operated without staff in attendance.

In making its plans the ITA has taken account of the Postmaster-General’s directive that wherever possible the ITA and BBC should share transmitter masts. At three sites this has required a new type of mast: exceptionally tall in order to give sufficient range, and very strong in order to carry all the aerials needed for existing ITA and BBC services and all foreseeable television and FM sound services. These three new masts have been built by the ITA of tubular steel instead of the usual open lattice construction. The two at Emley Moor in Yorkshire and Belmont in Lincolnshire are 1,265 feet high, the tallest manmade structures in Europe. The third, at Winter Hill in Lancashire, is 1,015 feet high.

Technical characteristics of transmitting stations, particularly channel frequencies, require the Postmaster-General’s approval and by international agreement are designed to minimise interference with the services of neighbouring countries.

The ITA employs an engineering staff of over 250 of whom some 200 are at the transmitting sites. Under the Chief Engineer, the engineering staff is divided into three sections – the Planning and Construction Department which builds the stations, the Operations and Maintenance Department which runs them, and the Telecommunications and Experimental Department which organises the programme distribution network and runs an experimental and investigational laboratory.

The Post Office builds and operates the network of inter-city cables and many of the microwave links between studios and transmitters so that programmes produced in one region can be distributed in others. Switching arrangements are planned at the ITA’s headquarters; the switching itself is carried out at a number of Post Office Network Switching Centres throughout the country.

Where practicable and economic the Authority always places its research work with British industry, but the Telecommunications and Experimental Department has a small well-equipped laboratory which studies specialised reception and radio propagation problems; undertakes the design of prototype equipment; as occasion demands operates a mobile field strength measuring unit; and takes part in national and international research programmes.

Fremont Point