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 <li...@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 <li...@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@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@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@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@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@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.