"Jim Lesurf" wrote
I suspect that GPS would have too poor a short-term phase stability for
'direct' use due to atmospheric propagation errors. However they may use it
for medium and long term reference checks on the 'local' clock used at any
antenna station. Countries like the USA, UK, etc transmit clock signals by
radio as well for these purposes. Rugby MSF is the one most people know
about and the long term accuracy of this should be good. There are loads of
these all around the world, though, often at a few MHz IIRC.

Isn't Rugby at some very low frequency like 60 kHz?

I have one of thos increasingly ubiquitous mini radio-"controlled" alarm
clocks. Th'******* woke me up in the middle of the night recently. The alarm
was set for 07:00 but it woke me at 01:00 or something. Dunno what happened,
or why it did it, but it scared the living crap out of me: "What? It can't
be time to get up already! Oh NOOOO. No, not now!" I guess it must have
messed up when syncing itself at midnight or something. Imagine my relief
when I finally worked out that it wasn't time to get up! Scary though! What
made it do that?! Maybe a ghost or something! Aaarggh!! (And I don't even
believe in ghosts, but I can get very scared at night in the dark, alone.)


Martin
--
M.A.Poyser Tel.: 07967 110890
Manchester, U.K. http://www.fleetie.demon.co.uk