hayes chronograph - test-drb@ccmp.vtda.org

26 Jul 2001

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