This is a timeline of the development of radio in Wales.
1970s
1970
No events.
1971
No events.
1972
12 July – Following the enabling of The Sound Broadcasting Act 1972, The Independent Broadcasting Authority is formed, paving the way for the launch of Independent Local Radio.
1973
No events.
1974
30 September – Swansea Sound, the first Independent Local Radio station in Wales, begins broadcasting to the Swansea area.
1975
No events.
1976
No events.
1977
3 January – BBC Radio Cymru is launched.
1978
Autumn – Four experimental local radio stations broadcast in Wales for a single week: Radio Deeside, Radio Merthyr, Radio Rhondda and Radio Wrexham 13 November – Due to Radio 4's forthcoming transfer from medium wave to long wave, BBC Radio Wales launches as a full-time station on Radio 4's former Welsh medium wave opt-out wavelength of 340m (882 kHz), albeit initially with very limited broadcast hours due to very limited coverage of BBC Radio 4 on FM in Wales. 23 November – All BBC national radio stations change their medium or long wave transmission wavelength as part of a plan for BBC AM broadcasting in order to improve national AM reception, and to conform with the Geneva Frequency Plan of 1975. Radio 1's transmission wavelength is moved from 247m (1214 kHz) to 275 & 285m (1053 & 1089 kHz) medium wave. Radio 2's wavelength is moved from 1500m (200 kHz) long wave to 433 & 330m (693 & 909 kHz) medium wave. Radio 3 is moved from 464m (647 kHz) to 247m (1215 kHz) medium wave. Radio 4 is moved from various medium wavelengths to 1500m (200 kHz) long wave.
1979
November – A weekday mid-morning programme launches on BBC Radio Cymru, thereby extending its broadcasting hours to 65 hours each week. Previously, apart from extended news bulletins at lunchtime and early evening, and some off-peak opt-outs, the station had only been on air at breakfast time.
1980s
1980
February – BBC Radio Deeside is launched as an opt-out service from BBC Radio Wales. 11 April – CBC in Cardiff becomes the first of the second tranche of Independent Local Radio stations to start broadcasting. It is the first new ILR station since 1976.
1981
October – BBC Radio Deeside is expanded to cover all of north east Wales and is renamed BBC Radio Clwyd.
1982
No events.
1983
18 April – BBC Radio Gwent launches as an opt-out service from BBC Radio Wales. 13 June – Gwent Broadcasting becomes the first station in the UK to occupy the newly released 102.2 to 104.5Mhz part of the VHF/FM waveband. 6 October – Centre Radio stops broadcasting after running into financial difficulties. A take-over bid was rejected by the IBA and the station went off air at 5.30pm.
1984
No events.
1985
13 February – Financial difficulties force South Wales station Gwent Broadcasting to close down after less than two years on air. 14 October – At 6am, CBC is relaunched as Red Dragon Radio and broadcasts a 24-hour schedule - CBC had previously closed down between 1am and 6am. The station also covers the Newport area, offering a replacement service to Gwent Broadcasting, and provides separate breakfast shows for Cardiff and Newport until the early 1990s.
1986
The Home Office sanctions six experiments of split programming on Independent Local Radio. Up to ten hours a week of split programming is allowed. Marcher Sound is one of the stations to take advantage of this so that it can provide some programming in Welsh.
1987
No events.
1988
29 September – BBC Radio 1 starts broadcasting on FM in South Wales.
1989
31 March – Marcher Gold begins broadcasting on MW to Wrexham and Chester and the area's FM station is renamed MFM. 19 December – BBC Radio 1 starts transmitting on FM in the Cardigan Bay area.
1990s
1990
15 July – Touch AM begins broadcasting in South Wales with the area's FM station being renamed Red Dragon FM.
1991
March – BBC Radio Gwent stops broadcasting.
1992
14 December – Radio Ceredigion begins broadcasting to Aberystwyth and the West Wales Coast.
1993
1 July – Radio Maldwyn begins broadcasting on AM to the Montgomeryshire area of Wales. 27 August – Marcher Coast begins broadcasting. The station covers the north Wales coastal area from Llandudno eastwards. October – BBC Radio Clwyd closes, although news opt-outs continue until 2002.
1994
4 September – Galaxy 101 launches a dance music service to the Severn estuary area.