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Mendip transmitting station

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Coordinates:51°14′13″N2°37′31″W/ 51.2370°N 2.6253°W/51.2370; -2.6253
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Mendip
The Mendip UHF television mast
Mendip transmitting station is located in Somerset
Mendip transmitting station
Mendip transmitting station (Somerset)
Mast height293 m (961 ft)
Coordinates51°14′13″N2°37′31″W/ 51.2370°N 2.6253°W/51.2370; -2.6253
Grid referenceST564488
Built1967
BBC regionBBC West
ITV region
Local TV serviceTalkBristol

TheMendip transmitting stationis abroadcastingandtelecommunicationsfacility on the summit ofPen Hill,part of theMendip Hillsrange in Somerset, England, at 305 metres (1,001 ft) above sea level. The station is inSt Cuthbert Outcivil parish,approximately 2 miles (3.2 km) north-east ofWells.Its mast, 293 m (961 ft) high, was built in 1967 and is the tallest structure inSouth West England.The mast broadcasts digital television, FM analogue radio and DAB digital radio, and had broadcast analogue colour television from 1967 until 2010.

Description[edit]

The station is owned and operated byArqiva(which acquired National Grid Wireless, previously Crown Castle).

Until 2008 aGRPaerial cylinder, containing the analogue television transmittingantennas,was mounted at the top of the mast, bringing the total height of the structure to 305 metres (1,001 ft). With a mean height of 596 metres (1,955 ft) above sea level, these antennas were among the highest in the UK. They were removed in 2010, the antenna cylinder being replaced with a new antenna assembly, ready fordigital switchoverlater that year. The present assembly is slightly shorter than the previous cylinder, causing the overall mast height to be reduced from 305 metres (1,001 ft) to 293 metres (961 ft).[1][2]

There are redaircraft warning lamps(six sets of two lights) on the mast and two lights on top. The lights were upgraded in February 2007[3]to comply withCAA2000 Air Navigation Order, designed to prevent low flying aircraft from hitting the mast. The mast was repainted during 2007.

The mast can be seen from as far away asPuritonduring the day and the red aircraft warning lights make it visible at night from most of theSomerset Levelsand from areas of South Wales, such as the high ground near theWenvoe transmitting station.

Television[edit]

Mendip was configured as a C/D group transmitter when it entered service with analoguePALtransmissions. In July 2007,Ofcomconfirmed that it would remain a C/D group transmitter atdigital switchover.The mast broadcasts digital television over a large area of the west of England, includingSomerset,Wiltshire,Bristol,southernGloucestershire,and northernDorset.Northern Gloucestershire – such as most ofCheltenhamandTewkesbury– is outside the coverage area, instead receiving signals from theRidge Hilltransmitter in Herefordshire.[4]

Cardiff and other parts of southeastWaleswere also able to receive the analogue TV transmissions from Mendip,[5]and many households used it in preference to their more localWenvoetransmitter which carries the Wales variations of BBC One, BBC Two, and ITV. This was originally because the Wenvoe transmitter broadcastS4C(with programmes in Welsh and some prime-time English programmes from Channel 4 scheduled at much later times) rather than Channel 4 itself. Even after digital switchover when transmitters in Wales also began to broadcast Channel 4 in addition to S4C, some households continued with their preference for the West variations of BBC One, BBC Two, and ITV, and having Channel 4 (not S4C) as number 4 on the electronic programme guide.

Power on analogue transmissions was 500 kW (ERP) for BBC 1, BBC2, HTV West, Channel 4, and 126 kW (ERP) for Channel 5. The latter was transmitted outside of the original C/D grouping of the transmitter but most homes in reasonable signal areas for the C/D group could receive it with their C/D group aerial. All six digital multiplexes were transmitted at 10 kW until switchover in 2010 when the power on the "BBC A", "BBC B/HD" and "D3&4" multiplexes was boosted to 100 kW. In 2011, SDN was boosted to 50 kW and in 2012 the remaining two Arqiva multiplexes were boosted to 50 kW too.

In June 2019, as part of the 700MHz clearance programme, Mendip became K group (excluding muxes 7 and 8, which are due to be switched off between 2020 and 2022). This means that homes in poor signal areas which still have a C/D group aerial may have difficulty in receiving all multiplexes.[6]

Mendip's population coverage is around 1.5 million, although some homes in the immediate vicinity, such as those inCheddar,are unable to receive a signal due to being in the shadow of the Mendip Hills and therefore depend on local relays.

Radio[edit]

Mendip broadcastsFM(analogue VHF) radio forBBC Radio Somersetand the Severn Estuary regional serviceKiss 101.Mendip also transmits high powerDigital Audio Broadcasting(DAB) signals for theDigital One,Sound Digital andBBC National DABmultiplexes. An additional DAB multiplex,MuxCo Somerset,was awarded a licence in 2008 to broadcast local and national services to Somerset, and began transmission in 2014.[7]After the closure of the Severn Estuary digital radio multiplex, the equipment from Mendip was reused to improve coverage on the Welsh coastline for the Cardiff & Newport, now South East Wales, multiplex.[8][9]

Output[edit]

Radio[edit]

Analogue[edit]

Frequency kW[10] Service Notes
95.5MHz 5 BBC Radio Somerset
101.0 MHz 40 Kiss 101 Directional antenna towards South Wales[11]
102.6 MHz 4 Heart West

Digital[edit]

Frequency Block kW[10] Operator Notes
211.648 MHz 10B 1.2 MuxCo Somerset
216.928 MHz 11A Sound Digital Limited
222.064 MHz 11D 5 Digital One
225.648 MHz 12B 5 BBC National DAB
227.360 MHz 12C 1.5[8] South East Wales For improved coverage on the Welsh coastline[12]

Television[edit]

Analogue[edit]

1 December 1969 – 11 May 1970[edit]
Frequency UHF kW Service
815.25MHz 64 500 BBC2 West
11 May 1970 – 30 May 1970[edit]
Frequency UHF kW Service
767.25MHz 58 500 BBC1 West
815.25MHz 64 500 BBC2 West
30 May 1970 – 2 November 1982[edit]
Frequency UHF kW Service
767.25MHz 58 500 BBC1 West
791.25MHz 61 500 HTV West
815.25MHz 64 500 BBC2 West
2 November 1982 – 30 March 1997[edit]
Frequency UHF kW Service
735.25MHz 54 500 Channel 4
767.25MHz 58 500 BBC1 West
791.25MHz 61 500 HTV West
815.25MHz 64 500 BBC2 West
30 March 1997 – 15 November 1998[edit]
Frequency UHF kW Service
599.25MHz 37 126 Channel 5
735.25MHz 54 500 Channel 4
767.25MHz 58 500 BBC1 West
791.25MHz 61 500 HTV West
815.25MHz 64 500 BBC2 West

Analogue and digital[edit]

15 November 1998 – 24 March 2010[edit]

Digital terrestrial television was first transmitted from the Mendip mast from 15 November 1998 using the frequency gaps between the analogue TV broadcasts. To limit interference to the analogue transmissions, power output on the digital multiplexes was low.

Frequency UHF kW Operator System
599.25MHz 37 126 Channel 5 PALSystem I
735.25MHz 54 500 Channel 4 PAL System I
746.166MHz 55+ 10 Digital 3&4(Mux 2) DVB-T
754.166MHz 56+ 10 Arqiva(Mux C) DVB-T
767.25MHz 58 500 BBC1 West PAL System I
778.166MHz 59+ 10 BBC(Mux 1) DVB-T
791.25MHz 61 500 HTV West PAL System I
802.166MHz 62+ 10 SDN(Mux A) DVB-T
815.25MHz 64 500 BBC2 West PAL System I
826.166MHz 65+ 10 BBC (Mux B) DVB-T
842.000MHz 67 10 Arqiva (Mux D) DVB-T
24 March 2010 – 7 April 2010[edit]

On 24 March 2010 BBC2 was switched off on UHF 64 and HTV West was switched from UHF 61 for its final weeks of service. Multiplex 1 on UHF 59+ was closed and replaced by BBC A on UHF 61 (which had just been vacated by analogue HTV West). BBC A was transmitted at full power (100 kW) and in 64QAM, 8k carriers mode from the start.

Frequency UHF kW Operator System
599.25MHz 37 126 Channel 5 PALSystem I
735.25MHz 54 500 Channel 4 PAL System I
746.166MHz 55+ 10 Digital 3&4(Mux 2) DVB-T
754.166MHz 56+ 10 Arqiva(Mux C) DVB-T
767.25MHz 58 500 BBC1 West PAL System I
794.000MHz 61 100 BBCA DVB-T
802.166MHz 62+ 10 SDN(Mux A) DVB-T
815.25MHz 64 500 HTV West PAL System I
826.166MHz 65+ 10 BBC (Mux B) DVB-T
842.000MHz 67 10 Arqiva (Mux D) DVB-T

Digital[edit]

7 April 2010 – 28 September 2011[edit]

Following the completion of analogue TV shutdown on 7 April 2010, Mendip transmitted all of its higher powered multiplexes at 100 kW. From this date until the second-stage switchover of 28 September 2011 the frequency allocation was:

Frequency UHF kW Operator System
738.000MHz 54 100 Digital 3&4 DVB-T
754.166MHz 56+ 10 ArqivaA DVB-T
770.000MHz 58 100 BBCB DVB-T2
794.000MHz 61 100 BBC A DVB-T
802.166MHz 62+ 10 SDN DVB-T
842.000MHz 67 26 Arqiva B DVB-T
28 September 2011 – 28 March 2012[edit]

With the completion of digital switchover at Oxford, all multiplexes could be moved to their final channel allocations with the exception of Arqiva A. SDN increased to half its full power output (50 kW).

Frequency UHF kW Operator System
690.000MHz 48 50 SDN DVB-T
722.000MHz 52 25.7 ArqivaB DVB-T
738.000MHz 54 100 Digital 3&4 DVB-T
770.000MHz 58 100 BBCB DVB-T2
794.000MHz 61 100 BBC A DVB-T
842.000MHz 67 26 Arqiva A DVB-T
28 March 2012 – 26 March 2013[edit]

On 28 March 2012 Arqiva A moved to its final channel allocation at UHF 56, after the completion of digital switchover at Salisbury. Arqiva A and B and SDN also increased to full power (100 kW) on this date.[13]

Frequency UHF kW Operator System
690.000MHz 48 100 SDN DVB-T
722.000MHz 52 100 ArqivaB DVB-T
738.000MHz 54 100 Digital 3&4 DVB-T
754.000MHz 56 100 Arqiva A DVB-T
770.000MHz 58 100 BBCB DVB-T2
794.000MHz 61 100 BBC A DVB-T
27 March 2013 – 27 February 2018[edit]

BBC A moved from UHF 61 to UHF 49 to allow for the clearance of the 800 MHz band for 4G LTE mobile services.[14][15]

Frequency UHF kW Operator System
690.000MHz 48 100 SDN DVB-T
698.000MHz 49 100 BBC A DVB-T
722.000MHz 52 100 ArqivaB DVB-T
738.000MHz 54 100 Digital 3&4 DVB-T
754.000MHz 56 100 Arqiva A DVB-T
770.000MHz 58 100 BBCB DVB-T2
27 February 2018 - 4 April 2019[edit]

Arqiva A has moved from UHF 56 to UHF 33 for the start of the 700MHz clearance programme at Mendip.

Frequency UHF kW Operator System
570.000MHz 33 100 Arqiva A DVB-T
690.000MHz 48 100 SDN DVB-T
698.000MHz 49 100 BBC A DVB-T
722.000MHz 52 100 ArqivaB DVB-T
738.000MHz 54 100 Digital 3&4 DVB-T
770.000MHz 58 100 BBCB DVB-T2
4 April 2019 – 5 June 2019[edit]

BBC A has moved from UHF 49 to UHF 32 as part of the 700MHz clearance programme at Mendip.

Frequency UHF kW Operator System
562.000MHz 32 100 BBC A DVB-T
570.000MHz 33 100 Arqiva A DVB-T
690.000MHz 48 100 SDN DVB-T
722.000MHz 52 100 ArqivaB DVB-T
738.000MHz 54 100 Digital 3&4 DVB-T
770.000MHz 58 100 BBCB DVB-T2
5 June 2019 - Present[edit]

Digital 3&4 has moved from UHF 54 to UHF 34, and BBC B have moved as well from UHF 58 to UHF 35 as part of the 700MHz clearance programme at Mendip. Many Welsh residents also prefer Mendip's service to the Wenvoe service as it provides a stronger signal to the coastline and areas in the shadow of the Wenvoe mast.

Frequency UHF kW Operator System
562.000MHz 32 100 BBC A DVB-T
570.000MHz 33 100 Arqiva A DVB-T
578.000MHz 34 100 Digital 3&4 DVB-T
586.000MHz 35 100 BBCB DVB-T2
594.000MHz 36 100 ArqivaB DVB-T
690.000MHz 48 100 SDN DVB-T

See also[edit]

References[edit]

  1. ^"Mendip".The Big Tower.Retrieved6 April2018.
  2. ^"Mendip".mb21.Retrieved26 March2024.
  3. ^http:// cheddarvalleygazette.co.uk/displayNode.jsp?nodeId=216909&command=displayContent&sourceNode=216903&contentPK=16636764&moduleName=InternalSearch&formname=filtersearch[permanent dead link]
  4. ^"Ridge Hill (County of Herefordshire, England) Full Freeview transmitter".UK Free TV.1 May 2004.Retrieved26 March2024.
  5. ^"UHF Analogue TV Transmitters – Mendip".mb21 UK Broadcast Transmission.Mike Brown.Retrieved7 February2021.
  6. ^"Mendip Transmitter".A.T.V. Poles, Brackets, Clamps & Aerials.Retrieved7 February2021.
  7. ^"South West England and Wales"(PDF).Frequency Finder. Archived fromthe original(PDF)on 19 February 2009.Retrieved23 August2011.
  8. ^abhttps:// ofcom.org.uk/__data/assets/pdf_file/0030/83829/south_east_wales_dab_coverage_plan_final_report_jan15.pdf[bare URL PDF]
  9. ^"Technical parameters for broadcast radio transmitters".Ofcom.9 May 2022.Retrieved17 April2023.
  10. ^abRadio Listeners Guide 2010
  11. ^https://fmscan.org/power.png.php?i=2801161[bare URL]
  12. ^"mb21 - The Transmission Gallery".tx.mb21.co.uk.Retrieved17 April2023.
  13. ^"Corporate"(PDF).7 February 2023.
  14. ^Butterworth, Brian (13 January 2012)."2013 - post-switchover changes to Freeview transmission frequencies".ukfree.tv.Retrieved22 July2019.
  15. ^"Corporate".7 February 2023.

External links[edit]

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