 His father, a cousin of Harry Clarke, had been a republican activist during the Irish War of Independence before studying, and then teaching, at the RHA schools.Mac Conghail was educated at University College Dublin.He joined Raidió Teilifís Éireann (RTÉ) in the 1960s, one of a group of young broadcasters which included Aindreas Ó Gallchóir, Breandán Ó hEithir, James Plunkett Kelly, Donal Farmer and Seán Mac Réamoinn.