John Kasupski wrote:
Yes, assuming it can get a signal...which problem exists with the
WWVB-based devices as well (and which was the whole point of the
article cited by the OP).

That is a problem of any radio based device, whether it uses GPS,
60kHz (or the European equivalent) signals, cell phone, etc.

I understand that analog TV signals in the U.S. also had time
coding in them to eliminate the flashing "12:00" problem.
Of course that's about to go away, and I have no idea if U.S.
HDTV signals include time coding or not.

When someone asked on another list about this several months ago,
so that he could get an heirloom digital clock to receive the 60kHz
signals in a place that was too well shielded and electricaly noisy,
I looked into generating the time signals with a PC. :-)

Programing wise it was simple, one could take the system clock
and build the data stream. If it was kept in sync with NTP, it
would be close enough for those clocks that only display to
minute or second resolution.

The problem for me was building a transmitter, because such parts
are almost impossible to get locally, and I had no clock to test
it and not much chance of getting one.

At some point I would like to build and market a WiFi NTP clock,
but that has to wait.


IOW, self-setting clocks as consumer items are a convenience, not a
necessity. I'd be more concerned about wireless phones not working due
to the fact that this renders them useless for placing emergency
calls, rather than because it prevents these devices from updating
their time displays.

Good point.

Geoff.


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Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
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