National Physical Laboratory

Why can't I receive MSF on 2.5, 5 and 10 MHz? (FAQ - Time)

When they started in 1950 the Rugby MSF signals were intended primarily as frequency sources and the transmissions were on frequencies allocated to this purpose, 2.5, 5 and 10 MHz in the h.f. (high frequency, short wavelength) bands, initially only for a few half-hour periods during the day. In May 1953 these h.f. services became 24 hours/day but with regular five-minute breaks to allow other signals to be received. The 60 kHz service did not become 24 hours/day until 1966. The MSF h.f. services on 2.5, 5 and 10 MHz ceased at the end of February 1988 as they were of little use nationally, and more accurate methods were available for long-range comparisons. It has taken some time for the information about the withdrawal of these services to spread.

Last Updated: 25 Mar 2010
Created: 9 Aug 2007


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