Knock More transmitting station

The Knock More transmitting station (sometimes spelled "Knockmore") is a broadcasting facility, located at Knock More,[1] to east of the parish of Boharm, Scotland, in Moray (grid reference NJ322497). It is a guyed steel lattice mast which stands 113 metres (371 ft) high. The mast is located on elevated ground which is about 355 m above sea level,[2] and is between Elgin and Keith. It was built by the Independent Broadcasting Authority (IBA) to improve and extend UHF television coverage in north east Scotland, and is now owned and operated by Arqiva.[3]

Knock More
Knock More transmitting station is located in Moray
Knock More transmitting station
Knock More transmitting station (Moray)
Locationnear Boharm, Moray
Mast height113 metres (371 ft)
Coordinates57°31′56″N 3°08′06″W / 57.532332°N 3.135127°W / 57.532332; -3.135127
Grid referenceNJ322497
BBC regionBBC Scotland
ITV regionSTV North

Coverage

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Knock More broadcasts to an area of Scotland which lies between the transmission areas of the Durris and Rosemarkie stations,[4] primarily in the Moray region of Scotland. There is good reception of Knock More in Buckie, Elgin, Dufftown, Keith, Lhanbryde and Lossiemouth. The Rumster Forest station also provides an overlap and alternative television signal along the coastal area between Burghead and Banff. Across the Moray Firth, reception of Knock More is also possible in coastal locations from Balintore and Brora as far north as Lybster.[5]

History

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The ITU conference held in Stockholm, Sweden in 1961[6] led to the planning of the UHF television broadcasting network in the United Kingdom.[7] A high power UHF television transmitter was allocated for 625-line colour transmissions close to Banff, with the broadcasting channels 23/26/29/33 broadcasting at 100 kW effective radiated power (erp).

The station opened on 28 October 1974[8] broadcasting the BBC and ITV colour 625-line television channels on UHF band IV, using the PAL system, with horizontal polarisation.

Frequency UHF kW Service
487.25 MHz 23 100 ITV Grampian
511.25 MHz 26 100 BBC2
567.25 MHz 33 100 BBC1

Previously, 405-line television (broadcasting on the VHF bands I and III) had been available for many viewers from neighbouring transmitters at Meldrum and Rosemarkie (BBC)[9] and Durris, Mounteagle and Rumster Forest (ITV Grampian).

Programmes from Channel 4 opened on UHF channel 29 in April 1984, with BBC Radio broadcasts on VHF band II commencing from October 1984.[10]

Knock More also broadcast its UHF 625-line colour television programmes on alternative frequencies (UHF channels 66/55/59/62) in a south-westerly direction to provide a better source for the television relay at Grantown. The Grantown relay is located on high ground, and two of the incoming programme sources from Knock More (ITV on ch23 and BBC2 on ch26) would have experienced adjacent-channel interference from Rumster Forest (which broadcast on ch24 and ch27).

Interim Digital terrestrial television opened from 15 November 1999 at Knock More using channels 34, 30, 53, 60, and 56. Knock More had been considered a "group A" transmitter (UHF channels 21–34, Band IV). Three of the new digital multiplexes were in the upper part of Band V, which would have required some viewers to replace their aerials with a wideband[11] television aerial covering channels 21–68.

Full digital switchover completed on 22 September 2010, with the public service broadcast multiplexes using UHF channels 23, 26, and 29, and the commercial multiplexes on 53, 57, and 60.

The 700 MHz clearance event[12] in 2017 meant the commercial multiplexes were required to vacate their part of the television broadcasting spectrum, and as a result of this, a retune for viewers was required.

Current broadcasting

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Television

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As of 2023, Knock More broadcasts digital terrestrial television on the following UHF frequencies[13]

Frequency UHF kW Multiplex System
538.000 MHz 29 20 BBC B DVB-T2
554.000 MHz 31 20 BBC A DVB-T
570.000 MHz 33 10 SDN DVB-T
594.000 MHz 36 10 Arqiva A DVB-T
602.000 MHz 37 20 Digital 3&4 DVB-T
690.000 MHz 48 10 Arqiva B DVB-T

Analogue radio (FM VHF)

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[14]

Frequency kW Service
88.2 MHz 20 BBC Radio 2
90.4 MHz 20 BBC Radio 3
92.6 MHz 20 BBC Radio Scotland
94.8 MHz 20 BBC Radio 4
97.8 MHz 20 BBC Radio 1

Digital radio (DAB)

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Frequency Block Operator
218.640 MHz 11B Bauer Inverness
225.648 MHz 12B BBC National DAB

Relays

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Below is a list of DTT transmitters that relay television broadcasts from Knock More. (Note: only public service broadcast multiplexes are broadcast from these relay sites)[15]

Transmitter kW BBC-A BBC-B D3&4 Pol.
Aviemore 0.0026 28 25 22 V
Avoch 0.002 32 34 35 V
Balblair Wood 0.00263 32 34 35 V
Craigellachie 0.014 40 43 46 V
Grantown 0.07 44 41+ 47 V
Kingussie 0.02 46 43 40 V
Lairg 0.0026 44 41+ 47 V

References

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  1. ^ "Knockmore Transmitter · Aberlour AB38 9RL, UK". Knockmore Transmitter · Aberlour AB38 9RL, UK.
  2. ^ "Bing Maps". Bing Maps.
  3. ^ "Television transmission services". www.arqiva.com.
  4. ^ https://www.ofcom.org.uk/__data/assets/pdf_file/0023/48614/stv_v2.2.pdf
  5. ^ "Knock More UHF Post-DSO digital TV transmitters". tx.mb21.co.uk.
  6. ^ "Regional Radio Conferences". ITU.
  7. ^ "mb21 – The Transmission Gallery". txfeatures.mb21.co.uk.
  8. ^ "The Transmission Gallery Knock More 2004". Retrieved 19 November 2023.
  9. ^ "mb21 – The Transmission Gallery – UK TV in 1965". txfeatures.mb21.co.uk.
  10. ^ "mb21 – The Transmission Gallery". tx.mb21.co.uk.
  11. ^ "Wideband TV aerials". Ofcom. 23 September 2016.
  12. ^ "700 MHz Clearance Programme: The journey". www.freeview.co.uk.
  13. ^ "Ofcom Digital television transmitter details 12 October 2021". Retrieved 19 November 2023.
  14. ^ "Knockmore Transmitter". RadioDNS.uk.
  15. ^ "Ofcom: Digital television transmitter details". ofcom.org.uk.
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