History

This page documents a group of links set up for television destribution in south and west Wales. The first site to be established was at Mynydd Pencarreg in 1958: the BBC transmitter at Blaenplwyf used a "direct pickup" link, receiving the Wenvoe transmitter off-air with a short microwave link. For ITV a separate Wales (West and North) company was awarded a franchise to cover the coastal region. Transmitters were to be at Preseli, Arfon and Moel-y-Parc, with studios in Cardiff. The Post Office agreed to provide a link to Preseli and for the ITA to make arrangements to feed the other transmitters. At the same time the Post Office had agreed to provide a fully-engineered link for the BBC. Contract 23515 was awarded to GEC in November 1961, described as "Wenallt - Tall Drysch and Blaen Plwyf". The completion date was to be "1 December 1963, subject to access to buildings & towers by 1 August 1963" - but interim arrangements were made to allow Preseli to enter service in June 1962.

GEC's bid of £117,459 for a L6 GHz system was accepted, Marconi were unable to bid "due to present production position" and STC's offer of £174,030 was ruled out. The revised price at April 1966 was £133,984. The link required new sites at Wenallt, near Cardiff, Werfa and Llanllawddog which would become a "hub" with other links added subsequently. The sites were provided with varying forms of the "Standard Tower" with provision for horn antennas. The ITA site at Preseli (Tall Drysch) was equipped with a dish on the broadcast mast and the existing BBC link from Mynydd Pencarreg incorporated into the overall scheme.

Photos of the sites show dishes installed on short towers or telepgraph poles and "temporary equipment" which presumably had been used to provide the initial link for Preseli. The First extension to the system was addition of a link for the BBC transmitter at Haverfordwest. Contract 23543 was issued in November 1962 for "Llanllawddog - Woodstock" for a 2 GHz link: "The equipment to be ready for service by 1 May 1964...". GEC's bid of £25,254 was accepted, STC were unable to quote (since they did not produce 2 GHz equipment) and Marconi made a higher offer of £28,130. The link to Haverfordwest required a dish at high level on the tower at Llanllawddog.

The Haverfordwest transmitter entered service in February 1964, closing in 1984, however the Post Office link is understood to have been replaced by a "self-provided" BBC link. Blaen Plwf became a UHF transmitter site for BBC2 from December 1970. BBC1 was added in February 1972 and ITV in May 1973 - these dates may reflect delays in providing new links to 625-line colour standards. Links were provided later from Llanllawddog for the BBC services at the Carmel transmitter (BBC2 in-service July 1971, BBC1 August 1972) and for ITV at the Preseli transmitter (in-service August 1973). Channel 4 was similarly linked to Preseli (not Carmel). These arrangements reflect the original ownership of the transmitters: at Preseli the BBC used off-air reception of Carmel to feed their services.

A 1984 network diagram for the Cardiff Television Network Switching Centre shows the expected four television services routed via Wenallt to Llanllawddog for distibution to the three transmitter sites, plus an additional feed for the BBC FM services at Blaen Plwyf. A single circuit ran in the reverse direction from Blaen Plwyf to Wenallt with switching allowing this to be presented to the BBC Cardiff studios. Alternatively the protection channel from Swansea could be routed to the studio or connected to the protection channel towards Bristol (Purdown). These arrangements are assumed to have been provided for occasional outside broadcast use.

There is little information to suggest the links west of Wenallt carried any telephony traffic - however a link was added in 1977 running via Werfa to a new site at Swansea. By the mid-1990s Channel 4 had moved to new BT-provided fibre circuits and the BBC had migrated to Energis. It is likely the remaining analogue links for HTV to be "retired" as soon as alternative arrangements could be made.