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Radio controlled clocks

What are atomic or radio controlled clocks?

Atomic or Radio Controlled clocks achieve accurate time because they are controlled by radio transmitters which themselves receive their time signals from Caesium Atomic clocks. These clocks have an accuracy of 1 second in a million years.

What is the MSF Atomic clock receiver?

The controlling radio signal for the National Physical Laboratory’s clock is transmitted on the MSF 60Hz signal via the transmitter at Rugby, operated by British Telecom International. This should have a range of around 1500kms or 937 miles. All of the British Isles is within this radius.

What does MSF mean?

MSF has several meanings in the UK but in relation to the Rugby standard time and frequency transmission it is simply a three letter call sign to identify the source of the signal. When the service began in 1950 there where announcements every 15 minutes "MSF MSF MSF" in Morse code followed by speech, "This is MSF, Rugby, England, transmitting..."

Why doesn't my radio controlled clock set up?

As a general rule, the radio signal performs like a car radio or mobile phone in that it cannot necessarily be received everywhere. Black spots are likely to be valleys, metal clad buildings and so on. If there appears to be a problem receiving a signal then it is suggested that the clock is left by a closed window overnight when the signal is at its strongest.

There are occasions when the Rugby transmission is off. Normally this is because of maintenance and occurs on the first Tuesday morning of every quarter and for 2 weeks in summer.