Greenwich Time Signal a station jingle during Jakki Brambles' early show and Simon Mayo's breakfast show. This was not strictly crashing the pips as they were not intended to be, or mistaken for, an accurate time signal. At 8 am on 17 September 2008, to the surprise of John Humphrys, the day's main presenter on the "Today" programme, and Johnnie Walker, who was standing in for Terry Wogan on Radio 2, the pips went adrift by 6 seconds, and broadcast seven pips rather than six. This was traced to a problem with the pip generator, which was 'repaired' by switching it off and
BBC Radio 4 7pm its DAB output is usually in mono, even though many of its programmes are made in stereo (including its flagship drama "The Archers"), these can be heard in stereo only on FM, Digital TV on Freeview & Freesat (Ch. 704), Sky, Virgin and on line via BBC iPlayer radio. BBC World Service, which uses BBC Radio 4 FM & DAB frequencies between 01:00am and 05:20am, is in stereo, but only on Radio 4 FM & DAB and not on its own dedicated DAB channel. BBC Radio 4 Extra broadcasts in mono on DAB, but has always been in stereo