thebigtower |
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presely (preseli) |
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THE PRESELY STATION is the main UHF transmission site for the coastal county of Pembrokeshire in south-west Wales. Known as both Presely and Preseli, English/Welsh respectively, it is one of two significant transmitting stations in the vicinity, the second being the Haverfordwest transmitter that provides BBC National FM services and also acts as a UHF relay of Presely. Historically, the two stations combined represented the last example (in terms of opening dates) of ITA and BBC stations sited adjacent to each other for the purpose of providing 405-line television coverage. In its original capacity, Presely was the basis for the 405-line ITV regional service serving West and North Wales, as detailed below in VHF TELEVISION HISTORY. |
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Site Images 2004 / 2011 (740x430 or 930x570) |
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TRANSMISSION STRUCTURE |
The Presely mast is a triangular cross-section lattice stayed structure which is 235.4 metres (772-ft) high, surmounted by the main UHF transmitting aerial. It is supported by fifteen stay lines attaching to a total of nine ground anchoring blocks. DIGITAL SWITCHOVER AND AERIAL GROUPING |
Digital Switchover at Presely was implemented by the usual two-stage process, respectively taking place on 19 August 2009 and 16 September 2009, subject to COM4 and COM5 not adopting final power until 30 September 2009 and COM6 until 24 March 2010. The post-DSO channels allocated have enabled Presely to remain within the existing Aerial Group B bandwidth. |
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Aerials> Site 2004> Site 2011 (740x430 pixels or 930x570 pixels)> Supersize Images> UHF Coverage Map |
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Above: As this station is located firmly in Welsh-speaking territory, the station plates here offer only the Welsh spelling as opposed to both English and Welsh as seen at St Hilary. |
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The Presely station was built by the Independent Television Authority in order to extend their 405-line VHF Band III service to West Wales. The authority’s presence in Wales was established in January 1958 with the opening of the St Hilary transmitter which served South Wales (including the country's main population bases of Cardiff and Swansea) as well as the West of England. Commissioned as the authority’s second transmitter installation in Wales, Presely was to establish a dedicated ITV service for West and North Wales that would initially operate as a separate franchise area to that covered by St Hilary. Based at Foel Drych in Pembrokeshire, a mountainous site 1063-ft (324 metres) above sea-level, the Presely station was constructed and a 750-ft (228 metre) mast erected to support the transmitting aerial. Amplifying power delivered from one vision and one sound transmitter rated at 5kW and 1.25kW respectively, the aerial needed to meet specific coverage objectives whilst also complying with several power restrictions imposed to avoid co-channel interference. The aerial that was eventually produced beamed an Effective Radiated Power (e.r.p) of 100kW towards the east and south-east, which covered Carmarthenshire and provided a fringe overlap with the St Hilary service area. Across the south and west, Pembrokeshire itself was served by a 50kW signal, whilst a narrow beam of 80kW was direct north along the western coastline towards Cardigan Bay. Presely entered full programme service on 14 September 1962, transmitting on VHF Channel 8. The new region would however be based on the combined coverage of Presely plus a major relay station in North-West Wales (Arfon) and a further main station in North-East Wales (Moel-y-Parc). The intention had been for all three stations to be ready at the same time but this was thwarted by construction delays at the other two sites. The Arfon relay (serving the far north-west of Wales and Anglesey) eventually entered service on 9 November 1962, whilst the main station at Moel-y-Parc followed on 28 January 1963. The delay in bringing these two stations to air, whilst relatively minor, was to prove a critical factor in the subsequent financial failure of the region's franchise holder WWN (Teledu Cymru). From 15 February 1965, prompted by the behind-the-scenes takeover of the West and North Wales franchise by the South Wales and West operator (TWW) in 1964, the Welsh service carried by Presely, Arfon and Moel-y-Parc was extended to South Wales, with St Hilary providing this by means of a second transmitting aerial using VHF Channel 7. Within the coverage area of Presely, the service was enhanced with the addition of relay stations at Bala (from 26 July 1967), Ffestiniog (28 February 1968), Llandovery (30 August 1968) and Llandrindod Wells (1 July 1969). ANALOGUE UHF SERVICE START DATES |
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ITV |
: 16 August 1973 |
BBC1 |
: 1 September 1973 |
BBC2 |
: 1 September 1973 |
S4C |
: 1 November 1982 |
CH5 |
: 31 March 1997 |
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Aerials> Site 2004> Site 2011 (740x430 pixels or 930x570 pixels)> Supersize Images> UHF Coverage Map |
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STATION INFORMATION |
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Location: |
Foel Drych, Crymych, Pembrokeshire |
Grid Reference: |
SN172306 |
Landlord: |
Arqiva (Legacy: ITA/IBA/NTL Broadcast) |
Ground Height: |
324m |
BBC Region: |
Wales |
Mast Height: |
235.4m |
ITV Region: |
Wales |
Aerial Height: (*) |
564m |
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UHF Tx Number: |
12900 |
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(*) Average UHF aerial height above sea level (a.o.d) |
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Digital Television |
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Analogue Radio (FM) |
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: Ch/Polarisation/e.r.p |
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Service: |
(MHz) |
(e.r.p) |
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PSB1 |
: 43 / H / 20kW |
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Classic FM (VP): |
100.5 |
5.9kW |
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PSB2 |
: 46 / H / 20kW |
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Classic FM (HP): |
100.5 |
1.4kW |
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PSB3 |
: 50 / H / 20kW |
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Real Radio (South Wales): |
105.7 |
9.4kW |
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COM4 |
: 42 / H / 10kW |
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COM5 |
: 45 / H / 10kW |
Digital Radio (DAB) |
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COM6 |
: 49 / H /10kW |
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BBC National (Block 12B) |
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Digital One (Block 11D) |
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Mid and West Wales (Block 12D) |
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PRE-DIGITAL SWITCHOVER UHF TRANSMISSIONS |
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(Shutdown completed 16 September 2009) |
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Analogue Television |
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Digital Television |
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Service |
Ch/Polar/e.r.p |
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Service |
Ch/Polar/e.r.p |
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BBC1 |
: 46 / H / 100kW |
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Mux1 |
: 47 / H / 1.0kW |
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BBC2 |
: 40 / H / 100kW |
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Mux2 |
: 51 / H / 1.0kW |
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ITV1 |
: 43 / H / 100kW |
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MuxA |
: 39 / H / 2.0kW |
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S4C |
: 50 / H / 100kW |
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MuxB |
: 42 / H / 2.0kW |
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CH5 |
: 37 / H / 100kW |
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MuxC |
: 45 / H / 1.0kW |
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MuxD |
: 49 / H / 1.0kW |
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Arfon Blaenplwyf Carmel Llanddona Moel-y-Parc St Hilary Wenvoe |
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