The MSF 60kHz Time and Frequency signal broadcast from the BT Rugby radio
station ( http://www.npl.co.uk/time/ ) will be closed down from 9.00am on
Monday 20 September 2004 until 9.00am on 4 October. The interruption to the
transmissions is required to allow maintenance work to be carried out in
safety. The service will be restored overnight whenever possible, but this
will not always be feasible as extensive work is required on the aerial
masts.

The MSF transmitter has an estimated equivalent monopole radiated power
(EMRP) of 15kW and the horizontal radiation pattern is substantially
omni-directional. The signal provides a field strength exceeding 100
microvolts/metre throughout the UK, and it can be satisfactorily received
throughout much of north and west Europe.

http://www.rsgb.org/news/gb2rs.htm