Editing Greenwich Time Signal (section)

==Technical problems==
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 (DJ)|Johnnie Walker]], who was standing in for Terry Wogan on Radio 2, the pips went "adrift" by six&nbsp;seconds, and broadcast seven pips rather than six. This was traced to a problem with the pip generator, which was rectified by [[power cycling|switching it off and on again]].<ref>{{citation
|url=http://news.bbc.co.uk/1/hi/uk/7621996.stm
|title='Pips' slip in BBC radio error
|publisher=[[BBC News]]
|date=17 September 2008
|access-date=23 April 2009
}}</ref> Part of Humphrys' surprise was probably because of his deliberate avoidance of crashing the pips with the help of an accurate clock in the studio.

A sudden total failure in the generation of the audio pulses that constitute the pips was experienced on 31 May 2011 and silence was unexpectedly broadcast in place of the 17:00 signal. The problem was traced to the power supply of the equipment which converts the signal from the atomic clocks into an audible signal.<ref name=blog>{{cite web |url= http://www.bbc.co.uk/blogs/radio4/2011/06/what_happened_to_the_radio_4_p.html |title= What happened to the Radio 4 pips? |author= Denis Nowlan |date= 1 June 2011 |work= Radio 4 and 4 Extra Blog |publisher= BBC |access-date=2 June 2011}}</ref> Whilst repairs were underway the BBC elected to broadcast a "dignified silence" in place of the pips at 19:00.<ref>{{cite news |title= Radio 4's pips die |author= Harry Wallop |url= https://www.telegraph.co.uk/culture/tvandradio/8548683/Radio-4s-pips-die.html |archive-url= https://archive.today/20130421065620/http://www.telegraph.co.uk/culture/tvandradio/8548683/Radio-4s-pips-die.html |archive-date= 21 April 2013 |newspaper= The Telegraph |date= 31 May 2011 |access-date=31 May 2011}}</ref> By 19:45 the same day the power supply was repaired<ref name=blog/> and the 20:00 pips were broadcast as normal.<ref>[http://radiotoday.co.uk/2011/05/bbc-radio-4-reports-on-pips-failure/ "The Pips return from a 3&nbsp;hour break" ''Radio Today'' 31 May 2011] Retrieved 31 May 2011.</ref>