Machynlleth transmitting station explained

Machynlleth
Map Name:Wales Powys
Coordinates:52.5868°N -3.8841°W
Height2:30m (100feet)
Gridref:SH724004
Built:1965
Bbc:BBC Wales (1967-1982)

The Machynlleth transmitting station is a broadcasting and telecommunications facility located on a hill about 2.5km (01.6miles) west of the town of Machynlleth, in Powys, 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 14m (46feet) wooden telegraph poles (one for the transmitting aerials, one for the receiving aerials) erected on land that is itself about 92m (302feet) 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 30m (100feet) 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 30km (20miles) to the southwest, receiving its signal by direct off-air pickup.

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]

FrequencyVHFUHFkWService
5H0.05BBC1 Wales
570.02BBC1 Wales
600.02HTV Wales
630.02BBC2 Wales

1 November 1982 - January 1984

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

FrequencyVHFUHFkWService
5H0.05BBC1 Wales
530.02S4C
570.02BBC1 Wales
600.02HTV Wales
630.02BBC2 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.

FrequencyUHFkWService
530.02S4C
570.02BBC1 Wales
600.02HTV Wales
630.02BBC2 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.

FrequencyUHFkWServiceSystem
530.02S4CPAL System I
570.004BBC Mux ADVB-T
600.02HTV WalesPAL System I
630.02BBC1 WalesPAL 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.

FrequencyUHFkWService
530.004BBC Mux B
570.004BBC Mux A
600.004Digital 3&4

Analogue radio (FM VHF)

28 June 1965 - Early 1990s

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

FrequencykWService
89.4 MHz0.06BBC Light Programme
91.6 MHz0.06BBC Third Programme
93.8 MHz0.06BBC Welsh Home Service

Early 1990s - present

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

FrequencykWService
89.4 MHz0.06Radio 2
91.6 MHz0.06Radio 3
93.8 MHz0.06Radio Cymru
99.0 MHz0.06Radio 1
103.6 MHz0.06Radio 4

See also

External links

Notes and References

  1. Web site: TRANSMITTING AERIALS FOR THE MACHYNLLETH V.H.F. TELEVISION AND V.H.F. SOUND STATION - Technological Report No. E-114/10. BBC. August 1965.
  2. Web site: Archived copy . 2012-06-12 . https://web.archive.org/web/20090106035542/http://www.bbceng.info/Eng_Inf/EngInf_13.pdf . 2009-01-06 . dead . bbceng.info.
  3. Web site: About us. www.freeview.co.uk.