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The Llanidloes transmitting station is a broadcasting and telecommunications facility consisting of a self-supporting 23 m lattice mast erected on land that is itself about 245 m above sea level about 1 km to the west of the town of Llanidloes in Powys, Wales. It was originally built by the BBC,〔http://downloads.bbc.co.uk/rd/pubs/reports/1968-16.pdf〕 entering service just before Christmas 1966 transmitting the now-defunct 405-line VHF television system. Transmissions of the original three FM Radio services began in February 1967. Currently, the transmitter provides DVB-T digital television to the area, along with FM radio. With only 2 W ERP, the television broadcasts only cover the town of Llanidloes to the east, the radio broadcasts reach somewhat further east along the Severn valley towards Llandinam. ==Specifications and history== As built, the 405-line television and VHF FM radio services came (indirectly) from Wenvoe near Cardiff, and this site was therefore classed as a relay of Wenvoe. UHF television was added to the site in the late 1970s, launching with just the three programme services that were active at the time. S4C was added in 1982 when it launched. This made Llanidloes a very indirect off-air relay of Blaenplwyf, receiving its signal from Llandinam which relayed Long Mountain. Curiously, Long Mountain was classed as a relay of Blaenplwyf despite being fed from an SHF link from Blaenplwyf via Llangurig Link. A site was normally considered a "relay" only if it picked up its signal off-air. Across the UK, 405-line television was finally shut down in January 1985.〔http://www.pembers.freeserve.co.uk/405-Lines/Transmitters.gif〕 However, Llanidloes was closed early - in the second quarter of 1983.〔http://www.bbceng.info/Eng_Inf/EngInf_8.pdf〕 When digital television was introduced in 2009, the site formally became a relay of Long Mountain which had now become classed as a main transmitter in its own right. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Llanidloes transmitting station」の詳細全文を読む スポンサード リンク
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