 In February 2000, John O'Hara hired Caldwell as the overnight presenter with the newly relaunched Atlantic 252.His work there included the final live drivetime show from their studios at Mornington House in County Meath on Thursday 20 December 2001, at approximately 4.55pm this was followed by a specially compiled Tribute show produced by Enda Caldwell and Eric Murphy celebrating the station's 12-year history of broadcasting and featuring classic airchecks and playlist tracks from each year of Atlantic 252's history.During his time at Atlantic 252 Caldwell was reprimanded several times for getting Pringles crumbs in the station switchboard

On 26 September 2006, Caldwell moved to Luxembourg to take up a programming and presentation position at the newly relaunched Radio Luxembourg.