So, if you use phase-tracking hardware, it's good for three more weeks. Wonderful... not. :((
LORAN-C all over again! -John ================= > On Fri, Feb 22, 2013 at 06:01:46PM -0500, paul swed wrote: >> Donald from what I have been seeing they are consistent. > >> But there is a 1 hour period up around 1 or 2 pm est that >> they go back to the old modulation and that allows time >> clocks to lock. > > Just for information here (from their web page): > > Since October 29, 2012 at 1500 UTC (9:00 AM MDT), NIST > Radio Station WWVB has been broadcasting a phase modulation > (PM) time code protocol that has been added to the legacy > AM/pulse-width-modulation signal. > > This enhancement to the broadcast, which has been tested > throughout 2012, provides significantly improved performance > in new products that are designed to receive it. > > Existing radio-controlled clocks and watches are not > affected by this enhancement, and continue to work as before. > > Disciplined oscillator products that track and lock to the > 60 kHz WWVB carrier and were designed to work as frequency > standards, will not work with the PM signal and will now > become obsolete. > > A few radio controlled clocks that used information from the > carrier â specifically the Spectracom NetClock and receivers > manufactured by True Time during the 1970s and 1980s â will > no longer be able to read the time code and will also be > obsolete. > > To allow users of these receivers to migrate to new products, > the plan for implementing the new modulation protocol > includes a transition period that will extend until at least > March 21, 2013. > > During the transition period, the PM signal will be turned > off for 30 minutes twice per day, at noon and midnight > Mountain Standard Time (MST), allowing carrier tracking > receivers to temporarily acquire the legacy signal. > > HTC, > Herbert > >> At least thats what the spectracom 8170 does. Then it says >> its locked for a very long time even though it isn't. > >> Regards >> Paul >> WB8TSL > >> On Fri, Feb 22, 2013 at 3:35 PM, Donald Henderickx >> <[email protected]>wrote: > >>> Is wwvb consistent in the testing of there modulation scheme?I find >>> that >>> My Spectracom 8182 will stay in time sync for several days,and then >>> loose >>> it for five or six hours. Is any one else experiencing this? >>> I am thinking of trying my kinemetrics/truetime 60-TF to see if it >>> might >>> function. >>> Don Henderickx >>> ______________________________**_________________ >>> time-nuts mailing list -- [email protected] >>> To unsubscribe, go to https://www.febo.com/cgi-bin/** >>> mailman/listinfo/time-nuts<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts> >>> and follow the instructions there. > >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
