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词条 Llandrindod Wells transmitting station
释义

  1. Specifications and history

  2. Services listed by frequency

     Analogue television  4 December 1961 - 1964  1964 - 4 July 1969  4 July 1969 - Late 1975  Late 1975 - 1 November 1982  1 November 1982 - 3 January 1985  3 January 1985 - 26 August 2009  Analogue and digital television  26 August 2009 - 23 September 2009  Digital television  23 September 2009 – 22 May 2013  22 May 2013 – Present  Analogue radio (FM VHF)  4 December 1961 - Circa 1990  Present  Digital radio (DAB)  Present 

  3. See also

  4. References

  5. External links

{{Infobox UK transmitter
|name = Llandrindod Wells
|image =
|caption =
|map_name = Wales Powys
|coordinates = {{coord|52.260429|-3.43948|type:landmark_region:GB|display=inline,title}}
|height = {{convert|65|m|ft|0}}
|gridref= SO018634
|built = 1961
|demolished =
|collapsed =
|relay = Carmel
|BBC = BBC Wales
|ITV = ITV Wales
}}

The Llandrindod Wells transmitting station is a broadcasting and telecommunications facility located on high ground about midway between Llandrindod Wells and Rhayader, in Powys, Wales. It was originally built by the BBC, entering service in 1961 transmitting the now-defunct 405-line VHF television system and the original three FM Radio services.[1][2]

Currently, the transmitter provides DVB-T digital television to the area, along with FM radio and a single multiplex of DAB digital radio.

Specifications and history

Originally, the site has a guyed 65 m lattice mast erected on land that is itself about 440 m above sea level. Unusually for the era, when 405-line Independent Television came to the area in 1969, the ITV transmissions were hosted on the same mast as the BBC ones.

UHF television was added to the site in late 1975,[3] launching with just the three programme services that were active at the time. S4C was added in 1982 when it launched.

405-line television from this site was shut down in January 1985.[4]

In 1991, the site was re-engineered. A self-standing 75 m lattice mast was erected on the site, the services were transferred from the old mast on 13 November 1991. The television broadcasts primarily cover the towns of Llandrindod Wells (to the east), Builth Wells (to the southeast) and Rhayader (to the northwest).

[5]

On 23rd September 2009 all the analogue television transmissions from the station were switched off and replaced by 3 digital television signals carrying the basic Freeview (UK) television service. The digital service used the higher three channels previously used by the analogue services (42,45 and 49). In 2014 the UK telecommunications regulatory Ofcom decided that the 700MHz band should be cleared of digital television to be used for mobile broadband services by the summer of 2020. In anticipation of this decision, on the 22nd May 2013 the BBC A frequency was changed from channel 49 to channel 39.

[6] [7]

Services listed by frequency

Analogue television

4 December 1961 - 1964

BBC 405-line television started up with the site acting as an off-air relay transmitter of Wenvoe about 90 km to the south, near Cardiff. About 42 km south there is the 700 m ridge to the east of Pen y Fan which obstructs the line-of-sight, but the off-air signal was good enough, as evidenced by the BBC's 1963 report on long-distance rebroadcast links[8] (see map on page 8).

{{no2Frequency{{no2VHF{{no2kW{{no2Service
ch=1}}11.5BBC TV

1964 - 4 July 1969

BBC Wales launched from Wenvoe on 9 February 1964 on channel 13, and the off-air repeaters of Wenvoe (within Wales) were reconfigured to use this signal.

{{no2Frequency{{no2VHF{{no2kW{{no2Service
ch=1}}11.5BBC Wales

4 July 1969 - Late 1975

When ITV 405-line television commenced, the site additionally became an indirect off-air relay of Preseli about 90 km to the west. Available documentation does not state how the signal from Preseli was routed to Llandrindod Wells. There is a 30 km long stretch of high ground (the southern Cambrian hills) obstructing the direct signal from Preseli starting about 10 km to the west. However, the 100 W off-air relay at Llandovery is line-of-sight about 30 km away on a bearing of 218°.

Llandovery relay had been built a year earlier in 1968, and as can be deduced from the geometry of MB21's photos,[9] it was indeed chosen for the signal source. Eight yagi aerials (four in use, four as reserves) were needed to pick up a reliable signal off-air.

{{no2Frequency{{no2VHF{{no2kW{{no2Service
ch=1}}11.5BBC1 Wales
ch=9}}93HTV Wales

Late 1975 - 1 November 1982

When 625-line colour television was added, the site additionally became a relay of Carmel about 65 km to the southwest. This despite the fact that line-of-sight is obstructed about 24 km to the southwest by the slopes of Esgair Dafydd just north of the Sugar Loaf.

{{no2Frequency{{no2VHF{{no2UHF{{no2kW{{no2Service
ch=1}}11.5BBC1 Wales
ch=9}}93HTV Wales
ch=39}}392.25BBC1 Wales
ch=45}}452.25BBC2 Wales
ch=49}}492.25HTV Wales

1 November 1982 - 3 January 1985

Channel 4 was added to the set radiated from the site when it launched in November 1982. Being in Wales, Llandrindod Wells radiated the S4C variant.

{{no2Frequency{{no2VHF{{no2UHF{{no2kW{{no2Service
ch=1}}11.5BBC1 Wales
ch=9}}93HTV Wales
ch=39}}392.25BBC1 Wales
ch=42}}422.25S4C
ch=45}}452.25BBC2 Wales
ch=49}}492.25HTV Wales

3 January 1985 - 26 August 2009

405-line television was shut down across the UK and Llandrindod Wells' Band I and Band III transmitters ended their service after 24 years and 16 years respectively. From then until the start of the digital switchover 24 years later, only UHF television would be available from the site.

{{no2Frequency{{no2UHF{{no2kW{{no2Service
ch=39}}392.25BBC One Wales
ch=42}}422.25S4C
ch=45}}452.25BBC Two Wales
ch=49}}492.25ITV1 Wales (HTV Wales until 2002)

Analogue and digital television

26 August 2009 - 23 September 2009

The UK's digital switchover commenced, mirroring the changes taking place at the parent transmitter at Carmel. Analogue BBC Two Wales closed on channel 45 and ITV1 Wales took over on that frequency for what would be its final 3 weeks of service, vacating channel 49 as it did so. The new digital BBC A multiplex started up at full power in 64-QAM mode on channel 49.

{{no2Frequency{{no2UHF{{no2kW{{no2Service{{no2System
ch=39}}392.25BBC One WalesPAL System I
ch=42}}422.25S4CPAL System I
ch=45}}452.25ITV1 WalesPAL System I
ch=49}}490.4BBC ADVB-T

Digital television

{{col-start}}{{col-2}}

23 September 2009 – 22 May 2013

FrequencyUHFkWOperator
ch=42}}420.4Digital 3&4
ch=45}}450.4BBC B
ch=49}}490.4BBC A
{{col-2}}

22 May 2013 – Present

FrequencyUHFkWOperator
ch=39}}390.4BBC A
ch=42}}420.4Digital 3&4
ch=45}}450.4BBC B
{{col-end}}

Analogue radio (FM VHF)

4 December 1961 - Circa 1990

From the outset, Llandrindod Wells radiated the BBC's three FM radio services, acting as an off-air relay of Wenvoe.

{{no2Frequency{{no2kW{{no2Service
89.1 MHz1BBC Light Programme
91.3 MHz1BBC Third Programme
93.5 MHz1BBC Welsh Home Service

Present

Radio 2, Radio 3 and Radio Cymru still use the original frequencies that have been used since 1961. Radio 1 and Radio 4 commenced transmission from this site on 13 November 1991. Radio 4, along with Radio Cymru, have replaced the Welsh Home Service (later known as Radio Wales).

FrequencykWService
89.1 MHz1.4BBC Radio 2
91.3 MHz1.4BBC Radio 3
93.5 MHz1.4BBC Radio Cymru
98.7 MHz1.4BBC Radio 1
103.8 MHz1.4BBC Radio 4

Digital radio (DAB)

Present

FrequencyBlockkWOperator
225.648 MHz12B5BBC National DAB

See also

  • List of masts
  • List of radio stations in the United Kingdom
  • List of tallest buildings and structures in Great Britain

References

1. ^http://downloads.bbc.co.uk/rd/pubs/reports/1964-26.pdf
2. ^http://downloads.bbc.co.uk/rd/pubs/reports/1956-24.pdf
3. ^{{cite web|url=http://txlib.mb21.co.uk/main.php?g2_itemId=2209&g2_imageViewsIndex=3 |title=Welcome to the Gallery Upgrader |publisher=Txlib.mb21.co.uk |date= |accessdate=2013-05-28}}
4. ^{{cite web|url=http://www.pembers.freeserve.co.uk/405-Lines/Transmitters.gif |title=Archived copy |accessdate=2013-11-15 |deadurl=yes |archiveurl=https://web.archive.org/web/20120813054041/http://www.pembers.freeserve.co.uk/405-Lines/Transmitters.gif |archivedate=2012-08-13 |df= }}
5. ^{{cite web|url=https://ukfree.tv/transmitters/tv/Llandrindod_Wells|title=Freeview Light on the Llandrindod Wells (Powys, Wales) transmitter|publisher=ukfreetv|year=2018|accessdate=19 June 2018 |deadurl=no}}
6. ^{{cite web|url=https://www.ofcom.org.uk/__data/assets/pdf_file/0022/106933/700mhz-clearance-timescale-review.pdf|title=700 MHz clearance programme timescale review|publisher=Ofcom|year=2017|accessdate=15 June 2018 |deadurl=no}}
7. ^{{cite web|url=http://www.digitaluk.co.uk/operations/700mhz_clearance|title=700MHz clearance|publisher= DigitalUK |year=2018|accessdate=14 June 2018 |deadurl=no}}
8. ^http://downloads.bbc.co.uk/rd/pubs/reports/1963-10.pdf
9. ^{{cite web|url=http://tx.mb21.co.uk/gallery/gallerypage.php?txid=790&pageid=1092 |title=mb21 - The Transmission Gallery |publisher=Tx.mb21.co.uk |date=2012-02-07 |accessdate=2013-05-28}}

External links

  • MB21's page on BBC 405 TV to Wales and the West
  • 405 Alive's list of transmitters"
  • [https://web.archive.org/web/20120414222659/http://www.pembers.freeserve.co.uk/405-Lines/tx-list.html#BBC#BBC More details on 405-line BBC transmitters]
  • The Transmission Gallery: Photographs and Information
  • The 'ukfree' listing for Llandrindod Wells
{{Transmitter sites in Wales}}{{FM radio transmitter sites in Wales}}{{Wenvoe VHF 405-line Transmitter Group}}{{Preseli VHF 405-line Transmitter Group}}{{Carmel UHF 625-line Transmitter Group}}{{Carmel UHF DVB Transmitter Group}}{{Television transmitters in the UK}}

3 : Buildings and structures in Powys|Transmitter sites in Wales|Wenvoe VHF 405-line Transmitter Group

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