Taken from the NPL MSF site:

MSF is the radio signal which broadcasts the national time standard for the UK. From the 1st April 2007 the MSF service broadcast will transfer to Anthorn, up until then it will continue to be broadcast from Rugby. The MSF signal is the principal means of disseminating the UK national standards of time and frequency which are maintained by the National Physical Laboratory. Transmission is 24 hours a day, and the carrier frequency is maintained at 60 kHz to within 2 parts in 10^12.

What do the letters MSF stand for? Well, they do not stand for anything. MSF is simply a call sign which uniquely identifies the broadcast. M is one of three prefixes (2, G or M) allocated to the UK by international agreement for station identification. There is speculation that SF was intended to represent the words ‘standard frequency’, but NPL has no evidence for this.

Provision of the Service

The MSF 60 kHz standard time and frequency service is funded by the Department of Trade and Industry (DTI) as part of its provision of time and frequency measurement standards in the UK. The maintenance and development of those standards is carried out by the National Physical Laboratory (NPL), with the MSF 60 kHz signal currently being transmitted from the Rugby Radio Station by BT Radio Engineering Services under contract from NPL. From the 1st April 2007 the signal will be transmitted from Anthorn by VT Communications under contract from NPL.

The signal from Anthorn will be generated using atomic clocks and time code equipment provided by VT Communications. The broadcast signal is monitored and controlled relative to the national time standard at the NPL site in Teddington.

Signal Coverage

The transmitter at Anthorn is at latitude 54° 55′ N, and longitude 3° 15′ W.

The estimated equivalent monopole radiated power (EMRP) is 15 kW and the horizontal radiation pattern is substantially omnidirectional. The signal provides a field strength exceeding 100 µV/m throughout the UK, and it can be satisfactorily received throughout much of north and west Europe. The main cause of reception difficulties are local interference and screening due to nearby metalwork, for example in a steel-framed building.