National Physical Laboratory

What is MSF?

The MSF radio signal is a dedicated time broadcast that provides an accurate and reliable source of UK civil time, based on the NPL atomic clock time scale UTC(NPL). It is available 24 hours a day across the whole of the UK and beyond. The signal operates on a frequency of 60 kHz and carries a time and date code that can be received and decoded by a wide range of radio-controlled clocks.

The MSF signal was transmitted from Rugby Radio Station in Warwickshire from 1950 to 2007. It was then transferred to Anthorn Radio Station in Cumbria, from where it is still operated by Babcock International Group, under contract to NPL. The signal covers the whole of the UK, and can also be received throughout most of Northern and Western Europe. It is monitored against the national time standard at the NPL site in Teddington and corrected when necessary, meaning that it keeps very accurate time.

MSF Reception Difficulties

If your radio-controlled clock is having difficulty receiving the MSF signal, the Common Clock Problems page contains information about possible causes. The main causes of reception problems are local interference from electrical equipment or the blocking of the signal by nearby metalwork, for example in a steel-framed building.

Interruptions to the MSF signal

The MSF signal is taken off-air a few times a year for planned maintenance work. A list of the scheduled outages is available.

Last Updated: 27 Aug 2014
Created: 26 Oct 2011


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