[time-nuts] WWVB Clocks don't sync anymore (revisited)

Louis Williams lawilliams at alum.mit.edu
Wed Mar 20 11:46:54 EDT 2013

Have not commented on this list before but have followed it for some time.  Regarding WWVB, the signal here in Cincinnati shows a lower level of modulation than was being used immediately after the transition with some sort of phase shift identifier every 30 minutes for a minute or so.  I am watching it every few weeks using a Tracor 900.  Have not seen any explanation of modulation changes since the first one last year.


-----Original Message-----
From: Chuck Harris [mailto:cfharris at erols.com]
Sent: Wednesday, March 20, 2013 11:23 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] WWVB Clocks don't sync anymore (revisited)

The thing is, many of us on the opposite end of the country
from WWVB have to rely on favorable propagation to make our
clocks work reliably.  What happens if noon and midnight
aren't favorable times?

-Chuck Harris

Herbert Poetzl wrote:
> On Wed, Mar 20, 2013 at 02:34:19AM -0400, Bill S wrote:
>> Interestingly, I have three timepieces that will no longer
>> synch to wwvb.Two Radio Shack digital clocks and a Casio
>> wristwatch that I've worn for a couple of years and was always
>> pretty much dead on. Like Paul, I have an analog Lacrosse clock
>> that is running correctly. Nothing I've tried will make the
>> other clocks synch.
> Maybe this is related to the phase modulation time code
> protocol used by WWVB since October 29th, 2012.
> Their website also states that clocks using information
> from the carrier will no longer work, and that during the
> transition period (at least March 21st 2013), the PM
> signal will be turned for for 30 minutes twice a day
> (noon and midnight MST) so maybe check if the clocks
> sync then?

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