Machynlleth transmitting station

Machynlleth
Tower height 30 metres (98 ft)
Coordinates 52°35′12″N 3°53′03″W / 52.5868°N 3.8841°W / 52.5868; -3.8841Coordinates: 52°35′12″N 3°53′03″W / 52.5868°N 3.8841°W / 52.5868; -3.8841
Grid reference SH724004
Built 1965
BBC region BBC Wales (1967-1982)

The Machynlleth transmitting station is a broadcasting and telecommunications facility located on a hill about 2.5 kilometres (1.6 mi) west of the town of Machynlleth, in Gwynedd, Wales. It was originally built by the BBC,[1] entering service in June 1965 acting as a relay transmitter for the now-defunct 405-line VHF television system.

Specifications

The site originally consisted of a pair of 14 metres (46 ft) wooden telegraph poles (one for the transmitting aerials, one for the receiving aerials) erected on land that is itself about 92 metres (302 ft) above sea level. The television broadcasts primarily covered the town of Machynlleth and the villages of the upper Dyfi river valley.

625-line colour TV came to the site in the late 1970s. A new 30 metres (98 ft) self-supporting lattice mast was built to carry the UHF aerials but the original VHF TV and VHF radio services continued to use the site's original wooden poles.

The three original VHF radio transmitters were upgraded to stereo in late Spring 1983.[2]

The 405-line VHF television service closed across the UK in 1985, but Machynlleth's 405 line services closed a year early - in January 1984.

Machynlleth currently broadcasts digital television and analogue FM radio.

Services listed by frequency

Analogue television

28 June 1965 - Late 1970s

The transmitter was classed as a relay of Blaenplwyf about 30 kilometres (19 mi) to the southwest, receiving its signal by direct off-air pickup.

Frequency VHF kW Service
66.75 MHz 5H 0.05 BBC1 Wales

Late 1970s - 1 November 1982

Colour TV eventually arrived, with the site continuing to act as an off-air relay of Blaenplwyf for the 625-line services.[3]

Frequency VHF UHF kW Service
66.75 MHz 5H — 0.05 BBC1 Wales
759.25 MHz — 57 0.02 BBC1 Wales
783.25 MHz — 60 0.02 HTV Wales
807.25 MHz — 63 0.02 BBC2 Wales

1 November 1982 - January 1984

Channel 4 launched across the UK on 1 November 1982. Being in Wales, Machynlleth broadcast the S4C variant.

Frequency VHF UHF kW Service
66.75 MHz 5H — 0.05 BBC1 Wales
727.25 MHz — 53 0.02 S4C
759.25 MHz — 57 0.02 BBC1 Wales
783.25 MHz — 60 0.02 HTV Wales
807.25 MHz — 63 0.02 BBC2 Wales

January 1984 - 10 February 2010

405-line television was discontinued after 19 years of service. For the next 25 years there were to be no changes to the television output at this site.

Frequency UHF kW Service
727.25 MHz 53 0.02 S4C
759.25 MHz 57 0.02 BBC1 Wales
783.25 MHz 60 0.02 HTV Wales
807.25 MHz 63 0.02 BBC2 Wales

Analogue and Digital Television

10 February 2010 - 10 March 2010

Digital switchover started at Blaenplwyf and therefore at Machynlleth and all its other relays. BBC 2 was closed down on channel 63 and BBC 1 was moved from channel 57 to channel 63 for its final month of service. Mux A started up on the newly vacated channel 57 at full post-DSO power of 4 W.

Frequency UHF kW Service System
727.25 MHz 53 0.02 S4C PAL System I
762.000 MHz 57 0.004 BBC Mux A DVB-T
783.25 MHz 60 0.02 HTV Wales PAL System I
807.25 MHz 63 0.02 BBC1 Wales PAL System I

Digital Television

10 March 2010 - present

All the remaining analogue TV transmitters were shut down and the three multiplexes of Freeview Lite took over their frequencies.

Frequency UHF kW Service
730.000 MHz 53 0.004 BBC Mux B
762.000 MHz 57 0.004 BBC Mux A
786.000 MHz 60 0.004 Digital 3&4

Analogue radio (FM VHF)

28 June 1965 - Early 1990s

For its FM radio services, Machynlleth is an off-air relay of Blaenplwyf.

Frequency kW Service
89.4 MHz 0.06 BBC Light Programme
91.6 MHz 0.06 BBC Third Programme
93.8 MHz 0.06 BBC Welsh Home Service

Early 1990s - present

Radio 1 gained its own frequency and National Radio 4 was added.

Frequency kW Service
89.4 MHz 0.06 Radio 2
91.6 MHz 0.06 Radio 3
93.8 MHz 0.06 Radio Cymru
99.0 MHz 0.06 Radio 1
103.6 MHz 0.06 Radio 4

See also

References

  1. ↑ http://downloads.bbc.co.uk/rd/pubs/reports/1965-28.pdf
  2. ↑ http://www.bbceng.info/Eng_Inf/EngInf_13.pdf
  3. ↑ http://www.digitaluk.co.uk/transmitternetwork/tools__and__resources/almanac/installer_newsletters_transmitter_groups2009_pdfs/Installer_Newsletter_Blaenplywf_1_month_out_FINAL_7_Jan_10.pdf
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