Built in 1975 to replace the Athlone transmitter, it always carried RTÉ Radio 1 on 567 kHz, at 500 kW.
It was taken offline for a time in 2004 for major maintenance, with the Clarkstown transmitter in County Meath taking over Tullamore's AM broadcast.
[1] Tullamore ceased analogue broadcasts permanently on 24 March 2008,[2] as the Clarkstown longwave transmitter provides improved coverage of the United Kingdom at the same transmission power.
The antenna, a 290-metre (952') tall guyed mast, was the tallest structure in Ireland.
[4][5] For a time RTÉ Radio broadcast a second signal from the Tullamore site, on 252 kHz longwave, before the setting up of Radio Tara and the building of the Clarkstown mast, to which the frequency was allocated.