Re: [time-nuts] WWVB a different approach to d-bpsk-r (cheating)
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. One man's noise is another man's signal. The NIST coverage maps vary widely from night to day. I assume their night maps depend upon skywave. So depending upon where you live, the some skywave stuff may be very important. Maybe fancy (rather than low cost) receivers work without (in spite of) the skywave. -- These are my opinions. I hate spam. ___ 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.
Re: [time-nuts] WWVB a different approach to d-bpsk-r (cheating)
On 7/19/2012 1:30 PM, Hal Murray wrote: 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. One man's noise is another man's signal. The NIST coverage maps vary widely from night to day. I assume their night maps depend upon skywave. So depending upon where you live, the some skywave stuff may be very important. Maybe fancy (rather than low cost) receivers work without (in spite of) the skywave. Hal Life is never easy. I think wwvb should just connect a direct fibre to anyone that wants it. I could get rid of the RBs and CS etc. Oh well. Yes indeed I see the effects you are speaking of. So strangely during the day the gps tic lines up with a rising edge of the cycle. Kind of amazing actually as I am in Boston. At sunset and sunrise I do see at least a 7-10us shift and its variable. But I don't think any of this matters a lot. My logic is this wait for a gps tick or even a local tick Is the wwvb a plus cycle or minus. If minus flip to plus Can get all fancy then check a couple of cyles and make sure its plus or minus then flip. Also as diurnal shift occurs its usually slow enough that the system can keep flipping as needed to keep the plus cycle aligned to the gps tick. Lots of clever things can be done if the simple theory holds or is even reasonable. A subset of the approach is check if a + if not is it actually a minus or zero a fade. Do nothing if a fade. All to familiar here. So this is not at all hard to build program or test. Just have a few distractions at hand. 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.
Re: [time-nuts] WWVB a different approach to d-bpsk-r (cheating)
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.
Re: [time-nuts] WWVB a different approach to d-bpsk-r (cheating)
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.
Re: [time-nuts] WWVB a different approach to d-bpsk-r (cheating)
Paul, On 07/14/2012 10:56 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. As your house and antenna rig (nice antenna by the way) lies 2795060 m away from the WWVB transmitter house (approximation for north and south antenna phase-center to get a first measure) and considering that each 60 kHz cycle takes about 5 km (4996.54 m will do for approximation) it is not strange that they line up for you, as you are 559.399 cycles away from the WWVB antenna, and there are numbers of factors I haven't corrected for, like actual speed of light. How much ground wave are you seeing? Cheers, Magnus Very careful analysis does show a 1-2 us jitter and at diurnal shift I really expect something to change it has to. The amount of ionospheric reflection will most probably be part of it. Cheers, Magnus ___ 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.
Re: [time-nuts] WWVB a different approach to d-bpsk-r (cheating)
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.
Re: [time-nuts] WWVB a different approach to d-bpsk-r (cheating)
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.
