Droitwich Transmitting Station
Template:Short description Template:Use dmy dates
Template:Infobox UK transmitter
The Droitwich transmitting station is a large broadcasting facility for long-wave and medium-wave transmissions, established in 1934 in the civil parish of Dodderhill, just outside the village of Wychbold, near Droitwich in Worcestershire, England ({{#if:SO929663|[[Ordnance Survey National Grid|{{#if:Template:Yesno|Grid|grid}} reference]] {{#invoke:Ordnance Survey coordinates|oscoord|SO929663_region:GB_scale:25000|SO929663|name=}}}}). The site is the location of the British Broadcasting Corporation's most powerful long-wave transmitter, which together with the two Scottish long-wave transmitters at Burghead and Westerglen forms a network broadcasting on the same frequency. The masts can be seen to the east from the M5 motorway, between Droitwich and Bromsgrove, as well as to the west from the Herefordshire/Worcestershire border. At night, the two sets of aircraft warning lights are visible from a long distance. The station is owned and operated by Arqiva.
History
In February 1932, radio broadcasting strength tests took place at Wychbold and Whittington, Worcestershire.<ref>Birmingham Daily Gazette Friday 26 February 1932, page 5</ref>
By March 1932, it was decided to put the 5XX LW transmitter at Droitwich, at 120 kW, and to boost the Midland Regional to 70 kW there.<ref>Staffordshire Sentinel Saturday 5 March 1932, page 3</ref> The Wychbold site was chosen in December 1932.<ref>Birmingham Daily Gazette Thursday 15 December 1932, page 11</ref> The site was bought in March 1933, three miles north east of Droitwich.<ref>Birmingham Daily Post Saturday 25 March 1933, page 18</ref>
The foundations were built by May 1933.
In November 1933 the expected power was increased to 150 kW, as that was the maximum allowed under the Lucerne Plan, which took effect on 15 January 1934.<ref>Birmingham Daily Gazette Tuesday 16 January 1934, page 5</ref>
Tests began on Monday 30 July 1934 at 12.05am until 3am, to 31 August, except on Sundays. The station was expected to partly open on Thursday 6 September 1934, on 1,500 metres LW. It would open at 3.45pm until 4.15pm, then from 10.40pm in the evening. The first morning broadcast of the National programme would be the following day from 10.15am until 11.55am.<ref>Daily Express Tuesday 14 August 1934, page 15</ref>
The two masts were 180 tons each, Template:Convert apart. Power came from four 750-hp English Electric (in Rugby) 'L type' diesel engines,<ref>Staffordshire Advertiser Saturday 16 May 1936, page 6</ref> <ref>Film</ref> each connected to a 470-kW three phase alternator, producing enough power to supply 5,000 homes; exhaust from the engines powered the building's central heating. The engines ran at 375 rpm, with an output voltage of 415 V.<ref>Newcastle Evening Chronicle Saturday 8 September 1934, page 5</ref><ref>Tewkesbury Register Saturday 8 September 1934, page 6</ref>
First broadcasts
The first item was the 1923 The Merrymakers overture, by Eric Coates, played by the BBC Symphony Orchestra, conducted by Aylmer Buesst.<ref>Gloucestershire Echo Friday 7 September 1934, page 4</ref>
The full opening was on Sunday 7 October 1934. It was hoped a member of the Royal family would open the building, but none were available.<ref>Birmingham Daily Gazette Friday 5 October 1934, page 11</ref>
Technical specifications
The long-wave frequency used was 200 kilohertz (frequently referred to by the wavelength, 1,500 metres) until 1 February 1988<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> when it was changed to 198 kilohertz, and the power is currently 500 kilowatts. The carrier frequency is controlled by a rubidium atomic frequency standard in the transmitter building, enabling the transmission to be used as an off-air frequency standard. For long-wave, a T-aerial is used, which is suspended between two Template:Convert guyed steel lattice radio masts, which stand Template:Convert apart from each other. There are also two guyed medium-wave mast radiators at the site. The northerly mast is actually the transmitting antenna whilst the southern mast is a passive reflector causing the rf signal to form a cardioid pattern tending in a NE direction so as not to interfere with the similar set up in Bristol. The smaller mast system transmits digital radio signals. The main large system is used for transmitting AM medium-wave radio programmes on 693 kilohertz and 1053 kilohertz and, until 2023, on 1215 kilohertz.
The 2 transmitters used are Marconi B6042 units each rated at 250 kW. 2 power output valves are used in each unit and are vapatron types that boil water in the ceramic cooling jackets. The units use a form of pulse width modulation to give an overall electrical efficiency approaching 70%.
Transmissions
BBC Radio 4 is transmitted on 198 kHz long wave. This signal also carries radio data encoded using phase modulation, giving a time-of-day signal, and radio teleswitch control signals for certain electricity meters, including Economy 7 and other time-controlled tariffs. The planned end to the usage of this frequency for the Radio Teleswitch Service on 30 June 2025 was subsequently postponed.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref>Template:Cite press release</ref> although Radio 4 will end its longwave broadcasts by 26 September 2026.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
BBC Radio 5 Live is broadcast on 693 kHz medium wave (MW), providing coverage for most of the English Midlands and Wales at a signal strength (150 kW) which is one of the strongest for that station, equal to Brookmans Park and second only to Moorside Edge.
During World War II coded messages, which were read during normal programmed broadcasts, were sent to the French Resistance using the transmitter.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
In 2011, as a result of budget cuts, the BBC announced that there would be no re-investment in long wave transmissions, which may mean an eventual end to BBC Radio 4 Longwave broadcasts.<ref>Template:Cite news</ref> The same year, The Guardian reported that the transmitter relies upon a pair of glass valves, of which there are fewer than 10 left in the world, and the BBC did not believe it was safe enough to manufacture more, because "slightly faulty" replacements could cause catastrophic failure.<ref>Template:Cite news</ref>
In 2023, the BBC announced that it would end separate programming for BBC Radio 4 on longwave in March 2024,<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> with an intent to switch off its long wave transmitters on, or shortly after, this date.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> The separate long wave programming ended on 15 April 2024.<ref>End of an era for BBC despite Long Wave reprieve</ref>
Reception
The Radio 4 LW signal from Droitwich covers most of England and Wales. There are supplementary long-wave transmitters in Scotland (Burghead and Westerglen, both 50 kW). The station can also be heard clearly in most of the Republic of Ireland, particularly along eastern and southern counties. Reception is also possible in Western Europe, including Italy and Sweden.
Services available
| Frequency | kW | Service |
|---|---|---|
| 198 kHz | 500 | BBC Radio 4 |
| 693 kHz | 50 | BBC Radio 5 Live |
| 1053 kHz | 500 (night) 125 (day) | Talksport |
Formerly:
| Frequency | kW | Service | Ceased | |
|---|---|---|---|---|
| 1215 kHz | 200 | Absolute Radio | citation | CitationClass=web
}}</ref> |
See also
- List of masts
- List of radio stations in the United Kingdom
- List of tallest structures in the United Kingdom
- Radio teleswitch