Editing BBC Radio 4 (section)

===Main stations===
Each of these main stations were broadcast at approximately 1 [[watt|kilowatt]] (kW):
{| class="wikitable"
! Airdate
! Station ID
! City
! Initial frequency
|-
| 14 November 1922
| '''[[2LO]]'''
| [[London]]
| 822 kHz
|-
|rowspan="2"| 15 November 1922
| '''[[5IT]]'''
| [[Birmingham]]
| 626 kHz
|-
| '''[[2ZY]]'''
| [[Manchester]]
| 794 kHz
|-
| 24 December 1922
| '''5NO'''
| [[Newcastle upon Tyne]]
| 743 kHz
|-
| 13 February 1923
| '''5WA'''
| [[Cardiff]]
| 850 kHz
|-
| 6 March 1923
| '''5SC'''
| [[Glasgow]]
| 711 kHz
|-
| 10 October 1923
| '''[[2BD]]'''
| [[Aberdeen]]
| 606 kHz
|-
| 17 October 1923
| '''6BM'''
| [[Bournemouth]]
| 777 kHz
|-
| 14 September 1924
| '''[[2BE Belfast|2BE]]'''
| [[Belfast]]
| 689 kHz
|}

====Relay stations====
Each of these [[broadcast relay station|relay stations]] were broadcast at approximately 120 [[watt]]s (W):
{| class="wikitable"
! Airdate
! Station ID
! City
! Relay of
! Frequency
|-
| 16 November 1923
| '''6FL'''
| [[Sheffield]]
| 2ZY
| 980 kHz
|-
| 28 March 1924
| '''5PY'''
| [[Plymouth]]
| 6BM
| 887 kHz
|-
| 1 May 1924
| '''2EH'''
| [[Edinburgh]]
| 5SC
| 914 kHz
|-
| 11 June 1924
| '''6LV'''
| [[Liverpool]]
|rowspan="5"| 2ZY
| 906 kHz
|-
| 8 July 1924
| '''2LS'''
| [[Leeds]] and [[Bradford]]
| 935 kHz
|-
| 15 August 1924
| '''6KH'''
| [[Kingston upon Hull]]
| 896 kHz
|-
| 16 September 1924
| '''5NG'''
| [[Nottingham]]
| 920 kHz
|-
| 21 October 1924
| '''6ST'''
| [[Stoke-on-Trent]]
| 996 kHz
|-
| 12 November 1924
| '''2DE'''
| [[Dundee]]
| 2BD
| 952 kHz
|-
| 12 December 1924
| '''5SX'''
| [[Swansea]]
| 5WA
| 622 kHz
|}

The [[BBC Home Service]] was the predecessor of Radio 4 and broadcast between 1939 and 1967. It had [[regional variations]] and was broadcast on [[medium wave]] with a network of [[VHF]] FM transmitters being added from 1955. Radio 4 replaced it on 30 September 1967, when the BBC restructured and renamed its domestic radio stations,<ref name="history1960s" /> in response to the challenge of [[offshore radio]]. It moved to long wave in November 1978, taking over the 200&nbsp;kHz frequency (1,500 metres) previously held by [[BBC Radio 2|Radio 2]] - later moved to 198&nbsp;kHz as a result of [[Geneva Frequency Plan of 1975|international agreements]] aimed at avoiding interference (all [[International Telecommunication Union region|ITU Region]] 1 MW/LW broadcast frequencies are divisible by 9). At this point, Radio 4 became available across all of the UK for the first time and the station officially became known as Radio 4 UK, a title that remained until 29 September 1984.

For a time during the 1970s Radio 4 carried regional news bulletins Monday to Saturday. These were broadcast twice at breakfast, at lunchtime and at 17:55. There were also programme variations for the parts of England not served by [[BBC Local Radio]] stations. These included ''[[Roundabout East Anglia]]'', a VHF opt-out of the ''Today'' programme broadcast from [[BBC East]]'s studios in [[Norwich]] each weekday from 6.45&nbsp;a.m. to 8.45&nbsp;a.m.<ref name="round">{{cite web|url=http://www.bbc.co.uk/norfolk/content/articles/2005/09/09/local_radio_25_years_book_feature.shtml|title=BBC Radio Norfolk's 25th anniversary|date=9 September 2005|access-date=10 February 2012|publisher=BBC}}</ref> ''Roundabout East Anglia'' came to an end in August 1980, ahead of the launch of [[BBC Radio Norfolk]].<ref name="round"/>

All regional news bulletins broadcast from BBC regional news bases around England ended in August 1980, apart from in the southwest as until January 1983 there was no BBC Local Radio in the southwest so these news bulletins and its weekday morning regional programme, ''[[Morning Sou'West]]'', continued to be broadcast from the BBC studios in Plymouth on VHF and on the Radio 4 medium wave Plymouth relay until 31 December 1982.

The launch of [[BBC Radio 5 (former)|Radio 5]] on 27 August 1990 saw the removal of [[Open University]], schools programming, children's programmes and the ''Study on 4''/''Options'' adult education slot from Radio 4's FM frequencies. Consequently, the full Radio 4 schedule became available on FM for the first time. However, adult educational and Open University programming returned to Radio 4 in 1994 when Radio 5 was closed to make way for the launch of [[BBC Radio 5 Live]] and were broadcast until the end of the 1990s on Sunday evenings on longwave only.

Between 17 January 1991 and 2 March 1991 FM broadcasts were replaced by a continuous news service devoted to the [[Gulf War]], [[Radio 4 News FM]], with the main Radio 4 service transferring to long wave. Before this, Radio 4's FM frequencies had occasionally been used for additional news coverage, generally for live coverage of statements and debates in Parliament.

By the start of the 1990s, Radio 4 had become available on FM in most of the UK - previously FM coverage had been restricted mainly to England and south Wales. This meant that it was possible for the main Radio 4 service to be transferred from LW to FM, and this took place on 16 September 1991 with opt-outs - extra shipping forecasts, ''[[The Daily Service|Daily Service]]'' and ''[[Today in Parliament|Yesterday in Parliament]]'', joined in 1994 by ''[[Test Match Special]]''. Longwave also occasionally opted out at other times, such as to broadcast special services, the most recent being when [[Pope Benedict XVI]] [[Pope Benedict XVI's visit to the United Kingdom|visited Britain in 2010]].

On 30 May 2023, the BBC announced that Radio 4 will stop broadcasting opt-outs on long wave<ref>{{Cite web |title=BBC Radio 4 begins information campaign to transition listeners from Long Wave |url=https://www.bbc.co.uk/mediacentre/articles/2023/bbc-radio-4-long-wave-transition/ |access-date=2024-02-19 |website=BBC |language=en}}</ref> with the last opt-outs airing on 31 March 2024.<ref name="RXTV">{{cite web |last=Thornham |first=Marc |title=End of an era for BBC despite Long Wave reprieve |url=https://rxtvinfo.com/2024/end-of-an-era-for-bbc-despite-long-wave-reprieve/ |website=RXTV |date=15 March 2024 |access-date=1 September 2024}}</ref> The two displaced programmes, ''Daily Service'' and ''[[Yesterday in Parliament]]'' moved to [[BBC Radio 4 Extra]], although the latter was returned to the early morning Radio 4 schedule in April 2025. The daily amount of ''[[Shipping Forecast|Shipping Forecasts]]'' was reduced to be broadcast 2 times on weekdays and 3 times on weekends. ''Test Match Special'' moved to [[BBC Radio 5 Sports Extra]] on 31 July 2023. These end ahead of a planned switch-off of long wave transmissions by 2025.<ref name="RXTV"/>

BBC Radio 4's medium wave frequencies were switched off on 15 April 2024, which previously served as relays in areas with a weak LW signal to provide reception of BBC Radio 4 LW, such as Northern Ireland and south west England. Most were turned off at 12:27 PM BST and broadcast an endless closedown loop informing listeners to retune to other methods of reception.<ref>{{Cite AV media |url=https://www.youtube.com/watch?v=-z3kYvzXfEs |title=BBC Radio 4 'AM retune loop' - 15/04/2024 |language=en |access-date=2024-04-15 |via=www.youtube.com}}</ref><ref>{{Cite web |date=2024-03-21 |title=Date set for the closure of BBC Radio 4 medium wave frequencies |url=https://radiotoday.co.uk/2024/03/date-set-for-the-closure-of-bbc-radio-4-medium-wave-frequencies/ |access-date=2024-03-21 |website=RadioToday |language=en-GB}}</ref> The final transmitter to change into the closedown loop was the Plymouth relay on 774 kHz at 4:59 PM BST.<ref>{{Cite AV media |url=https://www.youtube.com/watch?v=vWR7DsTNXZM |title=BBC Radio 4 on 774 kHz - last minutes of regular broadcasting + closedown loop |language=en |access-date=2024-04-15 |via=www.youtube.com}}</ref> These relays stopped broadcasting the closedown loop and fell silent completely by 30 April 2024.<ref>{{Cite web |date=2024-04-24 |title=MWLIST quick and easy: Europe, Africa and Middle East |url=https://www.mwlist.org/mwlist_quick_and_easy.php?area=1&kHz=720 |archive-url=https://web.archive.org/web/20240424155425/https://www.mwlist.org/mwlist_quick_and_easy.php?area=1&kHz=720 |archive-date=2024-04-24 |access-date=2024-04-24 }}</ref>