"Majdi S. Abbas" <m...@latt.net> wrote: > On Sun, Nov 01, 2009 at 05:51:24PM -0500, Glenn Little WB4UIV > wrote:
>> My WWV clock at home and the master clock at the TV station that >> I am engineer for did not update to EST from EDT. >> Did anyone else see their WWV clock not change time for DST? > WWVB does have a bit that accounts for it, but most of those > clocks just try to update once a day, and if they take a single > bit error in the minute or two they check, they'll miss it. [...] > Majdi, N0RMZ I don't know if WWV receivers work this way, but WWVB clocks start looking at midnight and repeat every hour until 06:00, or until they get a valid signal. Once they update, they no longer look for the time signal until the next midnight. If the signal is strong enough to update at midnight, the clock will miss the time change at 2:00 am. So they will be off by one hour until the next update. In this case, the problem is not due to a weak signal causing a single bit error, it is due to a strong signal and receiving all the bits correctly on the first attempt. In my case, the GCD distance between Toronto and Fort Collins is 1333 miles (2144 km, 1158 nautical miles), and the direction is 269.6 degrees: <http://www.indo.com/distance/> The NIST WWVB Coverage maps show the signal in Toronto is good at 0000UTC, and the receiver will probably synchronize on the first attempt at midnight (0500UTC): <http://tf.nist.gov/stations/wwvbcoverage.htm> So all my WWVB clocks missed the time change on the first day. For reference, the clocks are HTAWI HAA-1203W 12" White Atomic Analog Wall Clock: <http://www.partshelf.com/ps-haa-1203w.html>> They have been on sale for $14.95 for several years, and I can recommend them highly. Good styling, very economical, and excellent reception. When I first got them, I was amazed to see them synchronize at 5:00pm local time when the signals are very weak in Toronto. The only problem is they make a loud tick every second, which is the same as any digital clock movement. One day I will take them apart and put a small resistor and speedup capacitor in series with the motor to quiet them. Regards, Mike Monett _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.