1950-2007 – The History of the MSF Time Signal Service

The GBR 16 kHz Time Signal Service started in 1927 and ceased in the summer of 1986. However, the MSF 60 kHz Time Signal Service continued, with numerous improvements in accuracy were made between 1950 and 2007. These key points are listed in the following table:





Essen Ring crystal oscillators and Cold Cathode Clocks introduced.

1 second in 60 years


MSF 60 kHz service extended to 24-hours a day.


National Physical Laboratory (NPL) take over control of the service and introduce Rubidium atomic frequency standards and transistorised digital clocks.

1 second in 3,000 years


Definition of the ‘second’ changed from astronomic to atomic. Leap seconds introduced.

Sept 1974

First time code transmitted on MSF.


Ceasium Beam atomic frequency standard introduced on Master chain.

1 second in 10,000 years

June 1977

The 1Hz time code was introduced. This code is still in use today to set radio controlled clocks, watches, etc.


New programmable microprocessor controlled clocks introduced. Designed and constructed ‘in house’ by Paul Menary.

Dec 1998

New Solid State (Telefunken) transmitter came into service, reducing maintenance outage times and electricity costs.

1 second in 15,000 years


MSF 60 kHz service moves to Anthorn Radio Station near Carlisle, ending 80 years of time signals coming from Rugby Radio Station.

Final MSF Time Signal Transmitter - Telefunken (7/2/02) Source: MJH

431 Final MSF Transmitter
Share this article: