On Jul 25, 14:54, Iggy Drougge wrote:
> I don't know what it's like in your part of the hemisphere, but there's
an
> atomic clock down in Germany which broadcasts its time. IUt's quite easy
to
> obtain clocks which rely on its signal, and I've seen designs for a
similar
> cartridge for the Atari ST. Can't remember whether it plugged into the
> parallel or cartridge port.
> Hmm, sounds very much like something that would be printed in Elektor or
C't.
Elektor did indeed publish a design -- in fact, more than one -- some years
ago, and other magazines have, too. The transmissions are pretty low
frequency (low end of long wave: 60kHz) so a receiver has to be accurately
controlled if it's going to work - most use crystal control.
> Anyway, that should be the optimal timekeeping device, assuming you can
come
> up with the hardware and that you're within reach of the transmitter.
The German one is DCF at Mainflingen (IIRC) and there's a similar
transmitter (MSF) at Rugby in the UK. There's at least one in the US
(Colorado) as well. See
http://www.npl.co.uk/npl/ctm/electronic_projects.html
for some ideas.
One of my erstwhile colleagues built a very nice receiver with an active
aerial (the signal is easily interfered with by other LF sources, eg
computers) and a Z80-based decoder driving a cuckoo clock (yes, with a
wooden cuckoo behind door, that comes out on the hour, and by courtesy of a
speech synthesis routine, says "At the third stroke, the time will be ....
KOO-koo .. KOO-koo .. KOO-koo". He had an eccentric sense of humour :-))
The clock is still used to provide time service accurate to a few
miliseconds across campus.
His web pages are no longer around, I think, but similar designs are to be
found at
http://www.nukem.freeserve.co.uk/contents/electronics/clock/ and
several other places.
--
Pete Peter Turnbull
Network Manager
University of York
Received on Thu Jul 26 2001 - 08:18:52 BST