The following is a list of Medium & Long Wave frequency allocations and/or licenced broadcasts allocated to the Republic of Ireland and Northern Ireland since the 1975 Geneva Frequency Conference (that covered MW & LW broadcasting in ITU Regions 1 & 3, essentially everywhere outside of the Americas) came into force on the 23rd November 1978.
The main source of evidence is taken from the second edition of the published parameters and allocations of GE75 published by the ITU in 1981 - this includes allocations that weren't originally claimed in the 1975 session, but had been applied for and added to the allocations since then (for example, several allocations assigned to the Enniskillen MW site that opened in the early 1980s) up to the publishing of the second edition. A third & fourth edition exist, but available PDF copies I have don't list frequency allocations, and of course there have been assignments granted since those versions as well that might not be listed here as I'm unaware of them.
If anyone can source new info or corrections to what I've published below (but not speculations or heresay), I'd most appreciate it.
Please note that not included here are frequencies used by unlicenced/pirate stations, this list simply refers to ITU registered frequencies and those licenced by authorities on both sides of the border, nor does it refer to allocations prior to 23/11/1978 - an exception to this may be made in only if it is relevant to a registered ITU allocation or a frequency was was licenced at some point.
Prior Notes...
* "GE75" - Refers to the 1975 World Frequency Conference allocation agreements
* "GE75 2E" - Refers to the publish second edition of the above by the ITU
* "ND" - Non-Directional transmitting antenna
* "Dir" - Directional transmitting antenna, some details in notes
* "Dep" - Deprecated (see the case of allocation swaps of 1143 & 1251 kHz)
* Degrees are given in three digits clockwise from due north i.e. 000 = north, 090 = east, 180 = south, 270 = west
* Hours & minutes are given in the 24 hour clock i.e. 1800 = 6.00 pm
* There were no allocations in GE75 2E for the international low-powered frequencies of 1485, 1584 & 1602 kHz in Northern Ireland.
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LONG WAVE
254/252 kHz - Tullamore/Clarkestown, 500kW ND 0600-1800, 500kW Dir 1800-0600
Notes: Originally allocated as "Tullamore 2" in GE75 2E, its first use in Ireland was by the unlicenced station Radio Nova in test transmissions between December 1985 & January 1986, possibly up to 50kW ERP but reported to be 15kW before transmissions were turned off. First put into legal use in September 1989 for Atlantic 252 on 254 kHz, later switched to 252 kHz in early 90's, ERP after 1800 hours was reduced to 100kW non-directional to meet directional restrictions agreed in GE75 with Finland & Algeria. Later used for Teamtalk 252, currently broadcasting RTÉ Radio 1 with a reported ERP of 150kW daytime & 60kW nighttime.
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MEDIUM WAVE
531 kHz - Dublin, 10kW ND
Notes: Not listed in GE75 2E, this was an allocation mentioned as being made available for interest by the then IRTC in 2000 for use at Beaumont, Dublin but has never been put into licenced use. Not listed in GE75 2E. Dubliners of a certain age may remember this frequency being the MW home of superpirate Sunshine 539/101 in the 1980's.
540 kHz - "Conamara"/Casla (Galway), 2kW ND
Notes: Used by Raidió na Gaeltachta for their MW network alongside 828 & 963 kHz. Was closed at some point in the late 1990's or early 2000's. Registered in GE75 as "Conamara".
549 kHz - Dundalk/Carrickroe (Monaghan), 50kW(?)
Notes: Not an original Irish allocation in GE75, this frequency was first used on an unlicened basis by UCB Ireland at Carrickroe from the late 1990's, under pressure from Comreg was closed down several years later. Later approved by the ITU as an allocation for Ireland during the 2000's and was licenced to Spirit Radio whom still hold the licence for this frequency but are at the time of writing off the air on MW. IIRC the frequency is cleared for 50kW ERP, but Spirit have reportedly never used more than 25kW when transmitting from Carrickroe on 549 kHz.
567 kHz - Tullamore, 500kW ND
Notes: A very familiar frequency for many Irish people of mid to older generations as/was the main MW frequency for RTÉ Radio 1. Closed in 2008, has not be reactivated since.
612 kHz - Athlone, 200kW ND
Notes: Not allocated on original GE75 agreement but later co-ordinated and mentioned in GE75 2E. Used by RTÉ for national MW coverage of Radio 2, later 2FM. Though cleared for 200kW, was reported as using a maximum ERP of 100kW. Closed in 2004, has not been reactivated since.
639 kHz - Slane, 100kW Dir
Notes: Directional restrictions limiting ERP 090-110 degrees to 4kW presumably to protect same channel allocation at Prague (1500 kW) in Czechoslovakia (later Czech Republic/Czechia). No knowledge of it ever being brought into licenced service.
666 kHz - Omagh, 1kW ND
Notes: Not mentioned in GE75 2E, but reportedly allocated to Omagh for 1kW non-directional from an old BDXC publication. No knowledge of it ever being brought into licenced service.
675 kHz - Dungarvan, 100kW Dir
Notes: Directional restrictions limiting ERP 080-100 degrees to 10kW presumably to protect same channel allocation to two transmitters in the Netherlands (Lopik & Roermond). No knowledge of it ever being brought into licenced service.
693 kHz - Enniskillen, 1kW ND
Notes: Commenced broadcasting BBC Radio 2 on this frequency in the early 1980's, transferred to BBC Radio 5 (now Radio 5 Live) in 1990. Current ERP reported to be 400W.
720 kHz - Lisnagarvey, 10kW ND & L/Derry, 0.3kW ND
Notes: Both sites listed as being synchronous services in GE75, broadcasting the BBC Radio 4 LW service as fill-in stations. Still transmitting to this day, with the Lisnagarvey TX using the Blaw-Know mast, L/Derry ERP reported to be 250 Watts.
729 kHz - Killarney, 100kW ND & Cork, 10kW ND
Notes: Both sites listed as being synchronous services in GE75 but it appears only Cork was ever put into service. Was used to transmit RTÉ Radio 1 inc. the RTÉ Radio Cork opt-out until that was discontinued in 2000. Cork transmissions closed in 2008 the same time as those on 567 kHz at Tullamore.
765 kHz - Enniscorthy, 100kW Dir
Notes: Directional restrictions limiting ERP 100-120 degrees to 4kW presumably to protect same channel allocation to Sottens (500kW) in Switzerland. No knowledge of it ever being brought into licenced service.
774 kHz - Enniskillen, 1kW ND
Notes: Commenced broadcasting BBC Radio 4 LW on this frequency in the early 1980's. Current ERP reported to be 500W.
792 kHz - L/Derry, 1kW ND
Notes: Used to broadcast BBC Radio Foyle from 1979 as an opt-out service of Radio Ulster, transmission ceased in 2021.
828 kHz - Cookstown, 0.15kW ND
Notes: Was used first by Townland Radio when it launched in 1997, became Goldbeat 828 in 1997. Station closed in 1999, allocation has not been used since.
828 kHz - Corca Dhuibhne/Ballydavid, 1kW ND
Notes: Used by Raidió na Gaeltachta for their MW network alongside 540 & 963 kHz. Was closed at some point in the 1990's.
873 kHz - Enniskillen, 1kW ND
Notes: Commenced broadcasting BBC Radio Ulster on this frequency in the early 1980's, not listed in GE75 2E. Had occasional news opt-outs serving Fermanagh & West Tyrone area in the 2000's in parallel to local 93.8 MHz FM outlet. Transmissions ceased in 2021.
891 kHz - Bundoran, 100kW ND
Notes: Listed in GE75, No knowledge of it ever being brought into licenced service.
909 kHz - Lisnagarvey, 10kW ND & L/Derry, 1kW ND
Notes: Both sites listed as being synchronous services in GE75 not just for themselves but also for additional transmitters in Britain. Originally broadcast BBC Radio 2, later to BBC Radio 5 in 1990 & 5 Live later on. Reported ERPs in 2023 are 5kW for Lisnagarvey and 280W for L/Derry.
936 kHz - Clonbur/An Fhairche, 0.1kW ND
Notes: Listed in GE75, presumably was sought as an allocation for an expansion of RnaG's MW network but I've never known a licenced service on this allocation
963 kHz - Tir Chonaill/Derrybeg, 10kW ND
Notes: Used by Raidió na Gaeltachta for their MW network alongside 540 & 828 kHz, was the highest powered outlet of its MW network. Was closed at some point in the 1990's.
990 kHz - L/Derry, ERP unknown
Notes: Not mentioned in GE75, was reported to be the allocated MW frequency for the ill-fated independent local radio station Northside Sound that was awarded a licence by the UK's IBA in the early 1980's but never launched before their licence was withdrawn. Not sure of licenced ERP but fairly sure was no higher than 1kW. By the time a local commercial radio licence was awarded to Q102 in the early 90's, a MW allocation was not offered, just 102.9 MHz FM only. No knowledge of this allocation ever being brought into licenced service.
1026 kHz - Belfast/Knock Breckan, 1kW ND
Notes: Listed in GE75 as Belfast with a ND ERP of 1kW, officially in service at the Knock Breckan site outside the city with a two mast system giving a maximum ERP of 1.7kW at 295 degrees. Still in service.
1053 kHz - Enniskillen, 1kW ND & L/Derry 1kW ND
Notes: Both sites listed as being synchronous services in GE75 2E not just for themselves but also for additional transmitters in Britain. First used for BBC Radio 1, both sites originally closed in 1994. In 1995 the L/Derry site was reactivated for new station Talk Radio UK (now Talk Sport) though the Enniskillen site was not. L/Derry site was closed in 2020.
1089 kHz - Lisnagarvey, 10kW ND
Note: Operates as part of a synchronous service in conjunction with several other transmitters in Britain. Originally broadcasting BBC Radio 1, closed initially in 1994, reactivated in 1995 for Talk Radio UK (now Talk Sport). Reportedly operating with a maximum ERP of 12.5kW.
1134 kHz - Belfast, 0.001kW ND
Note: Was used by the student radio station of Queens University Belfast (Queens Radio) for several years in the 2000's as a 1 Watt long-term RSL. Closure date on this frequency unknown.
1143 kHz - Westport, 50kW ND (dep.) & Dublin, 10kW ND & Cork, ERP Unknown
Notes: This is a bit busy. In the GE75 2E allocations, only Westport is mentioned with a maximum ERP of 50kW non-directional, though this seems to have changed later to 1251 kHz. In the interim, the ill-fated Centruy Radio were available for a time on 1143 kHz from transmitter sites in both Dublin & Cork prior to their closure - from memory the Dublin site had a reported ERP of 5kW and the Cork site had an ERP of 2kW. In a 2000 IRTC press release seeking expressions of interest in a possible Dublin MW service, it mentioned 1143 kHz being available at Beaumont with a maximum ERP of 10kW non-directional, but this allocation has not been put into service since Century Radio closed operations. When Radio Ireland (now Today FM) was launched as a later-on replacement for a national commercial radio service, it was exclusively on FM.
1188 kHz - Cork 1, 10kW ND
Notes: Listed in GE75, no knowledge of it ever being brought into licenced service.
1197 kHz - Ennsikillen, 1kW ND
Notes: Commenced broadcasting BBC Radio 3 on this frequency as a fill-in in the early 1980's, listed in GE75 2E but not the first. Closed in 1992, was not reactivated for use by Virgin Radio (now Absolute Radio) at launch in 1993.
1215 kHz - Lisnagarvey, 10kW ND & L/Derry, 0.3kW ND
Notes: Both sites listed as being synchronous services in GE75 2E not just for themselves but also for additional transmitters in Britain. Was used for BBC Radio 3 from 1978 to 1992 when their MW network closed. In 1993, the Lisnagarvey site was reactivated for Virgin Radio (later Absolute Radio) with a reported ERP of 16kW however the L/Derry site was not reactivated, leaving Lisnagarvey as the only MW outlet for Virgin/Absolute in Northern Ireland. The Lisnagarvey TX was switched off in 2023 when Absolute Radio closed their MW network down - Lisnagarvey reportedly being the last such site in the network to be powered down.
1251 kHz - Dublin 1, 20kW ND (dep.) & Westport, 50kW ND
Notes: GE75 lists the Dublin allocation, with Westport being originally assigned 1143 kHz. At some point later than the early 80's, Wesport was assigned this allocation with 1143 being transferred for use in Dublin, Cork & possibly elsewhere. Prior to GE75, the then 1250 KHz frequency was in use in Dublin for broadcasting RTÉ Radio 1 at some point until at least the 1960's.
1278 kHz - Dublin 2, 20kW ND & Cork, 10kW ND
Notes: Only the Dublin allocation was listed in GE75 2E, but this as well as a Cork transmitter on the same frequency (at the same site as the 729 kHz Radio 1/Radio Cork TX) was brought into service, exact date unknown, to extend RTÉ Radio 2/2FM's MW coverage in addition to the 612 kHz Athlone TX. Both transmissions closed around the same time as the Athlone 612 kHz TX and have not been reactivated since.
1287 kHz - Various UK LPAM, 0.001kW each (See below)
Notes: Several British Army bases in Northern Ireland used this frequency for 1 Watt long term RSL transmissions of BFBS Northern Ireland Radio at various barracks from the late 90's into the 2000's. In recent years all these transmissions in NI have closed down, either converting to FM community radio licences or just switched off altogether (some bases that had these MW transmissions no longer exist e.g. St. Lucia/Lisanelly barracks in Omagh).
1305 kHz - Athlone, 2kW ND
Notes: Allocated in GE75, No knowledge of it ever being brought into licenced service.
1323 kHz - Dundalk, 2kW ND
Notes: Allocated in GE75, No knowledge of it ever being brought into licenced service.
1341 kHz - Lisnagarvey, 250kW ND & L/Derry, 5kW ND
Notes: Both sites listed as being synchronous services in GE75, was the main frequency for BBC Radio Ulster's MW Network in addition to the Enniskillen 873 kHz outlet. L/Derry outlet was likely switched off when BBC Radio Foyle launched in 1979 on 792 kHz leaving Lisnagarvey as the sole outlet on this frequency. Reported maximum ERP in use at Lisnagarvey was 100kW, radiated from the Blaw-Knox mast. Closed down in 2021.
1359 kHz - Galway 2, 2kW ND
Notes: Listed in GE75, the IRTC awarded a special interest licence for this frequency to serve Galway city & environs in 2002 but was never launched.
1386 kHz - Limerick, 2kW ND
Notes: Allocated in GE75, does not appear to have ever seen active service. Like Galway 1359 kHz the IRTC sought applicants for a special interest service on this frequency but I can't remember if there were any applicants (let alone any award).
1413 kHz - Ring (Waterford), 2kW ND
Notes: Allocated in GE75, near Dungarvan. No knowledge of it ever being brought into licenced service.
1449 kHz - Waterford, 2kW ND
Notes: Allocated in GE75. No knowledge of it ever being brought into licenced service.
1485 kHz - International Low-power channel (see Notes)
Notes: The Republic of Ireland has five allocations on this frequency, all with an ERP of 1kW and non-directional. They are (1) Ballagan Point, Louth, (2) Carnsore Point, Wexford, (3) Erris Head, Mayo, (4) Malin Head, Donegal and (5) Mizen Head, Cork. Was often used by RTÉ for transmission of their traveling local radio roadshows during the 1980's. No other known licenced broadcast use otherwise.
1521 kHz - Craigavon, 0.5kW
Notes: Not listed in GE75 2E, broadcast Radio 1521 serving the North Armagh area in 1996. Name changed to Heartbeat 1521 in 1998, closed down in 1999. Aerial directivity unsure, but presumably non-directional.
1584 kHz - International Low-power channel (see Notes)
Notes: The Republic of Ireland has three allocations on this frequency, all with an ERP of 1kW and non-directional. They are (1) Ballingeary, Cork, (2) Bangor Erris, Mayo and (3) Wexford. In 2011 this allocation was used by Zenith Classic Rock as part of a temporary broadcast licence serving the south-east of Ireland; unusually, this transmission also included C-QUAM stereo. No other known licenced broadcast use otherwise.
1602 kHz - International Low-power channel (see Notes)
Notes: The Republic of Ireland has two allocations on this frequency, both with an ERP of 1kW and non-directional. They are (1) Drogheda and (2) Wicklow. No knowledge of it ever being brought into licenced service.