[time-nuts] WWVB a different approach to d-bpsk-r (cheating)

paul swed paulswedb at gmail.com
Sun Jul 15 01:58:01 UTC 2012


Might loose the signal not unusual and it did shift +5-8 us tonight aligned
to the diurnal shift.
So maybe this is not so crazy of an approach.
Regards
Paul

On Sat, Jul 14, 2012 at 5:53 PM, Bob Camp <lists at rtty.us> wrote:

> Hi
>
> Well between now and midnight, you will completely loose signal at least
> once. It's a pretty dramatic amplitude dip as sunset gets right to the
> "wrong" place.
>
> Bob
>
> On Jul 14, 2012, at 4:56 PM, paul swed wrote:
>
> > Bob
> > Yes nights are bad for me, east coast and MSF interference.
> > So it could be any number of 60 KHz crossing its just odd it lined up the
> > way it did and I double confirmed that I was not doing something silly
> like
> > using alternate triggers.
> >
> > Very careful analysis does show a 1-2 us jitter and at diurnal shift I
> > really expect something to change it has to.
> > Regards
> > Paul.
> >
> > On Sat, Jul 14, 2012 at 4:32 PM, Bob Camp <lists at rtty.us> wrote:
> >
> >> Hi
> >>
> >> The "zero crossing" is very arbitrary. If it's correct at the transmit
> >> site, it will then be off everywhere else by the speed of light /
> distance.
> >> You will appear to be correct  once every wavelength away from Colorado
> >> (roughly every 3 miles). You won't really be correct because you are
> >> looking at a different zero crossing.
> >>
> >> As long as you don't have sunset or sunrise between you and the
> >> transmitter,  WWVB is reasonably stable. At night you will get more
> signal,
> >> but also can have some skywave "stuff" in the mix.
> >>
> >> Bob
> >>
> >> On Jul 14, 2012, at 3:50 PM, paul swed wrote:
> >>
> >>> OK have been doing a lot of experimenting.
> >>> I was curious what is the GPS tick in relationship to wwvb. Especially
> >>> since it is a reliable 1 sec marker.
> >>> Using a Tbolt since everyone has one on the list. ;-) And monitoring
> the
> >> 10
> >>> us tick to the wwvb 60 Khz carrier on a scope. Amazingly and over at
> >> least
> >>> 2 hours now, the rising cycle of 60 Khz aligns to the 10 us Tbolt tick
> >>> rising edge. Expected some form of drift.
> >>>
> >>> Would not have actually thought there should be such a relationship or
> >> its
> >>> truly pot luck today.
> >>> WWVB today is also not running bpsk.
> >>>
> >>> Should such a relationship actually exist?
> >>> There is a clue in a 1985 article in ham radio magazine.
> >>> It went something like this. At any given instant the 60 Khz may
> jitter.
> >>> But for every 1 sec period there will be exactly 60,000 cycles.
> >>>
> >>> If it does stay aligned, then the cheating d-bpsk-r gets to be
> >> interesting
> >>> and very implementable.
> >>>
> >>> The approach using a micro to sample a squared up 60 Khz after the
> Tbolt
> >>> tic.
> >>> Perform 2-3 1 usec samples in the leading 90 degree signal.
> >>> Decide is it a 0 or 1 phase.
> >>> Select a inverted or non inverted 60 Khz into the output path to
> >> maintain a
> >>> constant phase 60 Khz for the old recvrs.
> >>>
> >>> Sure its cheating. But if this relationship is real I should be able to
> >>> implement the answer very quickly as a proof point.
> >>>
> >>> Have not heard if the NIST testing is completed or when the next one
> is.
> >>> But for today all of the rcvrs are working just fine.
> >>> Regards
> >>> Paul
> >>> WB8TSL
> >>> _______________________________________________
> >>> time-nuts mailing list -- time-nuts at febo.com
> >>> To unsubscribe, go to
> >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> >>> and follow the instructions there.
> >>
> >>
> >> _______________________________________________
> >> time-nuts mailing list -- time-nuts at febo.com
> >> To unsubscribe, go to
> >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> >> and follow the instructions there.
> >>
> > _______________________________________________
> > time-nuts mailing list -- time-nuts at febo.com
> > To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> > and follow the instructions there.
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>


More information about the time-nuts mailing list