In article <telecom26.73.5@telecom-digest.org>, <ranck@vt.edu> wrote:
> Now you can buy an electric clock that syncs up to WWVB fairly
> inexpensively ($30 or so) and WWVB's digital signal has a DST
> bit that is set/unset when the changes occur. The clock I have
> does wind itself forward 1 hour in the Spring, and 11 hours in
> the Fall.
Ha! I bought two of those before the last change, and this time they
didn't change! Frankly, I don't see why not. I reset the power to them
and let them re-sync to WWV and they set themselves to the wrong time.
I'm amazed by the failure. The tf.nist.gov website has an very nice
description of the signal they put out. The time is encoded in 60 bits,
with one bit transmitted per second. The DST status is encoded in the
last two bits. All the clocks have to do is monitor those bits to tell
whether to add an hour. Instead it looks like they actually hard-coded a
comparison to the date, which would be doing it the hard way.
John Meissen jmeissen@aracnet.com
[TELECOM Digest Editor's Note: That is where I am at. My one
'sure-proof' time device here is my LaCrosse Technology wristwatch,
which does it as you say, from the WWV(B) signal, but even it was
a bit sluggish getting to me on Sunday. My watch was exactly
correct (except for being off one hour) on Sunday because I somehow
lost the WWV signal. (The only time/condition under which I am
_almost_ always guarenteed to receive it is in the early morning
hours, with the wristwatch setting on the window sill in my back
bedroom which faces west). I foolishly removed the battery from the
watch in an effort to get it to reset correctly on Sunday morning.
The watch just blinked at me all day until about 2 AM Monday morning
when it captured the signal. PAT]
jmeissen@aracnet.com