Preseli transmitting station

Preseli
Height of mast 235.4 metres (772 ft)
Grid reference SN172306
Built 1962
BBC region BBC Wales
ITV region ITV Wales

The Preseli transmitting station (also spelt Presely) is a broadcasting and telecommunications facility, situated close to the village of Crymych, in Pembrokeshire, Wales (grid reference SN172306). It is owned and operated by Arqiva.

It has a 235.4 metres (772 ft) high guyed steel lattice mast. It was constructed in 1962 by the IBA to transmit ITV 405-line television with transmissions commencing on Band III channel 8 from antennas at 559 m (1,835 ft) above sea level. The triangle of antenna arrays aimed beams of signal towards Pembrokeshire, another lobe was directed towards western Carmarthenshire and a northward beam covered south western Cardiganshire. The northward beam from the site also fed the transmitter at Arfon in North Wales.

The Welsh region ITV programming was initially provided by Teledu Cymru which was taken over by TWW in 1964, and eventually HTV Wales who took over from 1968.

In 1971, three protesters from Cymdeithas yr Iaith Gymraeg were jailed for "conspiring to trespass" after gaining access to the site compound and climbing the lower section of the mast. This was part of a series of protests in Wales aiming to get a dedicated Welsh-language TV channel established. The campaign was eventually considered to have been mostly successful with the establishment of S4C (Sianel 4 Cymru) eleven years later.

The site was uprated in 1973[1] to transmit UHF 625-line PAL analogue television channels, starting with BBC1, BBC2 and HTV Wales, with S4C being added in late 1982. The VHF channel 8 transmissions were discontinued in January 1985 as 405-line TV in the UK was phased out. Channel 5 started analogue TV transmissions in 1997. Six digital TV multiplexes were added in 1998 and the site kept this configuration until 2009, when all analogue television signals were permanently switched off.

The mast also carries Classic FM on 100.5 MHz and Real Radio on 105.7 MHz, and transmits national digital radio multiplexes for the BBC and Digital One multiplexes.

Transmissions

Analogue television

14 September 1962 - 16 August 1973

Frequency VHF kW Service
189.75 MHz 8 100 HTV Wales (TWW until 1968)

16 August 1973 – 1 November 1982

Colour TV eventually came to West Wales. This was fairly late by UK standards, but even the area's M.P. couldn't get it started any quicker.[2]

Frequency VHF UHF kW Service
189.75 MHz 8 — 100 HTV Wales
623.25 MHz — 40 100 BBC2 Wales
647.25 MHz — 43 100 HTV Wales
671.25 MHz — 46 100 BBC1 Wales

1 November 1982 – 3 January 1985

The launch of Channel 4 (S4C in Wales) took the UHF capabilities of the site to its design maximum. Being in Wales, this transmitter radiated the S4C variant.

Frequency VHF UHF kW Service
189.75 MHz 8 — 100 HTV Wales
623.25 MHz — 40 100 BBC2 Wales
647.25 MHz — 43 100 HTV Wales
671.25 MHz — 46 100 BBC1 Wales
703.25 MHz — 50 100 S4C

3 January 1985 – 30 March 1997

The VHF television transmitter was shut down after 22 years and 3 months of service.

Frequency UHF kW Service
623.25 MHz 40 100 BBC2 Wales
647.25 MHz 43 100 HTV Wales
671.25 MHz 46 100 BBC1 Wales
703.25 MHz 50 100 S4C

30 March 1997 – 15 November 1998

Channel 5 started broadcasting on UHF channel 37. A fifth analogue TV channel was outside the design specifications of the British UHF transmitter plan and this forced the use of out-of-band channel 37 which was supposed to be kept clear of transmissions.

Frequency UHF kW Service
599.25 MHz 37 100 Channel 5
623.25 MHz 40 100 BBC Two Wales
647.25 MHz 43 100 HTV Wales
671.25 MHz 46 100 BBC One Wales
703.25 MHz 50 100 S4C

Analogue and digital television

15 November 1998 – 19 August 2009

This was the initial roll-out for digital television using the DVB-T system. The transmitter frequencies and power outputs were chosen not to interfere with the UHF TV channels, but to be received with the same aerial-group. The QAM constellations and number of carriers were changed around 2002 after the collapse of ITV Digital as the service was taken over by the Freeview consortium.

Frequency UHF kW Service System
599.25 MHz 37 100 Channel 5 PAL System I
618.000 MHz 39 1 SDN (Mux A) DVB-T
623.25 MHz 40 100 BBC Two Wales PAL System I
641.833 MHz 42- 2 BBC (Mux B) DVB-T
647.25 MHz 43 100 ITV1 Wales (HTV Wales until 2002) PAL System I
665.833 MHz 45- 1 Arqiva (Mux C) DVB-T
671.25 MHz 46 100 BBC One Wales PAL System I
682.166 MHz 47+ 2 BBC (Mux 1) DVB-T
697.833 MHz 49- 1 Arqiva (Mux D) DVB-T
703.25 MHz 50 100 S4C PAL System I
714.166 MHz 51+ 2 Digital 3&4 (Mux 2) DVB-T

19 August 2009 – 16 September 2009

BBC Two Wales on channel 40 closed after 36 years of service, and HTV Wales was moved from channel 43 to the vacated channel 40 for what would be its final month of service.

Multiplex 1 on channel 47+ was renamed BBC A and moved to channel 43+ (which had just been vacated by analogue HTV Wales). In addition to the power increase to 20 kW ERP, it was reconfigured to 64QAM and 8k carriers, which resulted in a service area similar to the old analogue transmissions but with much more bandwidth available than Multiplex 1 ever had.

For the duration of the switchover, all the channels carried on Multiplex B were duplicated on this new PSB1 multiplex.

Frequency UHF kW Service System
599.25 MHz 37 100 Channel 5 PAL System I
618.000 MHz 39 1 SDN (Mux A) DVB-T
623.25 MHz 40 100 ITV1 Wales PAL System I
641.833 MHz 42- 2 BBC (Mux B) DVB-T
650.166 MHz 43+ 20 BBC A DVB-T
665.833 MHz 45- 1 Arqiva (Mux C) DVB-T
671.25 MHz 46 100 BBC One Wales PAL System I
697.833 MHz 49- 1 Arqiva (Mux D) DVB-T
703.25 MHz 50 100 S4C PAL System I
714.166 MHz 51+ 2 Digital 3&4 (Mux 2) DVB-T

Digital television

16 September 2009 – 31 October 2012

All remaining analogue television was shut down after 36 years of service. The pre-switchover low-power digital transmissions (apart from Arq A and SDN) were upgraded to full power and configured to 64QAM and 8k carriers, with some frequency changes and with new names for the multiplexes:

Frequency UHF kW[3] Operator
641.833 MHz 42- 10 SDN
650.166 MHz 43+ 20 BBC A
665.833 MHz 45- 10 Arqiva A
674.166 MHz 46+ 20 Digital 3&4
697.833 MHz 49- 10 Arqiva B
706.166 MHz 50+ 20 BBC B

31 October 2012 - present

As a side-effect of frequency-changes elsewhere in the region to do with clearance of the 800 MHz band for 4G mobile phone use,[4] Preseli's "Arqiva B" multiplex was moved from channel 49- to channel 39+ and the "BBC B" multiplex was moved from channel 50+ to channel 40+.[5]

Frequency UHF kW[6] Operator
618.166 MHz 39+ 10 Arqiva B
626.166 MHz 40+ 20 BBC B
641.833 MHz 42- 10 SDN
650.166 MHz 43+ 20 BBC A
665.833 MHz 45- 10 Arqiva A
674.166 MHz 46+ 20 Digital 3&4

Analogue radio (FM VHF)

September 1992 - September 2003

First FM transmissions from Preseli.

Frequency kW Service
H V
100.5 MHz 1.4 5.9 Classic FM

September 2003 - present

Frequency kW[7] Service
H V
100.5 MHz 1.4 5.9 Classic FM
105.7 MHz 9.4 — Real Radio Wales

Digital radio (DAB)

20 April 2006 - present

Frequency Block kW Operator[8]
222.064 MHz 11D 1 Digital One
225.648 MHz 12B 5 BBC National DAB

See also

References

  1. ↑ "ITV75p146w". Txlib.mb21.co.uk. Retrieved 2014-05-31.
  2. ↑ "Television Transmitter, Preseli (Hansard, 9 November 1970)". Hansard.millbanksystems.com. 1970-11-09. Retrieved 2014-05-31.
  3. ↑ Television Viewers Guide 2009
  4. ↑ Martin Bryant (2012-02-15). "EU States Must Allow 4G on Analogue TV Spectrum". Thenextweb.com. Retrieved 2014-05-31.
  5. ↑ "4G clearance retunes". a516digital. 2010-06-08. Retrieved 2014-05-31.
  6. ↑ Television Viewers Guide 2009
  7. ↑ Radio Listeners Guide 2010
  8. ↑ "News". ukdigitalradio. Retrieved 2014-05-31.

External links

Coordinates: 51°56′40″N 4°39′40″W / 51.94444°N 4.66111°W