27 Jul
2001
27 Jul
'01
10:33 a.m.
Hello,
At 07:27 PM 7/26/2001 +0000, Shawn T. Rutledge wrote:
I have an alarm clock which sets itself from this
signal. Of course the
first such clock (old enough to be on topic, even) AFAIK was the Heathkit
Most Accurate Clock. But those cost big bucks. Nowadays I'm seeing more
commercial clocks which do this, at reasonable prices.
I have a Radio Shack alarm clock that does this, they've been
on sale for $40 or so. I've even seen a big, wall-sized clock
at Costco that syncs to the broadcast time signal for $20.
The University of North Carolina just spent $20K or so outfitting
all of it's classrooms with this type of clock, I guess so the
students won't have an excuse for being late to the next class ;-)
WWV is broadcast on at least 5, 10 and 15 MHz
(exactly); maybe other
frequencies too, I'm not sure. And I think some of the transmitters are
in other places besides Colorado, the idea being that everywhere in the US
you can always receive at least one of them. I'm not sure which freq(s)
these clocks listen to.
Most (maybe all) of the "atomic-controlled" clocks sold as consumer products
synchronize to the WWVB transmissions on 60 KHz out of Ft. Collins,
Colorado. There is a nice description at the NIST web site:
http://www.boulder.nist.gov/timefreq/stations/wwvb.htm
Regards,
Alex Knight
The Calculator Museum Web Page
http://www.calcmuseum.com