Радиосигнал точного времени от Национальной физической лаборатории Великобритании

Time signal transmitted from Anthorn Radio Station near Anthorn, Cumbria

The Time from NPL is a radio signal broadcast from the Anthorn Radio Station near Anthorn, Cumbria, which serves as the United Kingdom's national time reference. The time signal is derived from three atomic clocks installed at the transmitter site, and is based on time standards maintained by the UK's National Physical Laboratory (NPL) in Teddington. The service is provided by Babcock International (which acquired former providers VT Communications), under contract to the NPL. It was funded by the former Department for Business, Innovation and Skills; as of 2017 NPL Management Limited (NPLML) was owned by the Department for Business, Energy and Industrial Strategy (BEIS), and NPL operated as a public corporation. The signal, also known as the MSF signal (and formerly the Rugby clock), is broadcast at a highly accurate frequency of 60 kHz and can be received throughout the UK, and in much of northern and western Europe. The signal's carrier frequency is maintained at 60 kHz to within 2 parts in 1012, controlled by caesium atomic clocks at the radio station. Eventually, time signals from GBR were terminated in November 1986 and it is no longer used as a frequency reference. From May 1953, the signal was broadcast 24 hours a day, but with regular five minute stoppages to allow the reception of other signals. The 60 kHz signal finally became an uninterrupted 24 hour service in 1966, and the frequency references were discontinued in February 1988. The Anthorn station was operated by VT Communications from its opening in 2007 until 2010, when it was acquired by Babcock International. The formal inauguration of the relocated facility took place on 1 April 2007, when the name of the service became "The Time from NPL" and the signal from Rugby was permanently switched off. The change in location and consequent change in signal strength can make some equipment designed to use the MSF signal fail to continue doing so. This is found more in domestic equipment not designed for optimum sensitivity and positioned haphazardly. Currently, the signal from Anthorn is still useable, in the location of the Mediterranean, although it is weaker than Rugby.

From the time signal's inauguration in 1950 until 1 April 2007 it was transmitted from Rugby Radio Station near Rugby, Warwickshire. Following its relocation in 2007 to Cumbria, the NPL now formally calls the signal "The Time from NPL". According to the NPL it seems the call sign was chosen so that it could be memorized as "Master Standard Frequency" but MSF was not intended to be an abbreviation.

The transmitted signal has an effective radiated power of 17 kW, on a frequency of 60 kHz to within 2 parts in 1012. The signal can also be received, and is widely used, in northern and western Europe.

MSF does not broadcast any explicit advance warning of upcoming leap seconds, which occur less than once a year on average. The only indication is a change in the number of padding bits before the time code during the minute before the leap second. Therefore, unless a leap second announcement is manually entered into a receiver in advance, it may take some time until an autonomous MSF receiver regains synchronization with UTC after a leap second (especially if the reception is not robust at the time of the leap second). The time signal only provides 1 hour warning of summer time changes.

MSF normally broadcasts continuously, but is occasionally taken out of service for scheduled or unscheduled maintenance. The Time from NPL Web site reports upcoming scheduled maintenance outages, and information on unscheduled outages.