Re: [time-nuts] WWVB Clocks don't sync anymore (revisited)
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. Bill_S W2FMA On 3/19/2013 5:29 PM, paul swed wrote: Funny you bring this up. I am just noticing a sharp clock that I always use and it has been accurate. But it did not flip with the time change this time and though it says its locked its off by 45 seconds slow. Yet a lacross clock across the room seems to be on second wise but never flipped with the time change. As I say its just becoming apparent. Regards Paul WB8TSL On Tue, Mar 19, 2013 at 4:55 PM, Clint Turner tur...@ussc.com wrote: A few weeks ago I posted a question/comment about some of my WWVB-based Atomic clocks no longer setting themselves properly. These two clocks, SkyScan #86716, would show the symbol indicating that they had set themselves, but their time was drifting away from UTC. Interestingly, they *would* set themselves exactly once upon installation of the battery, but never again. Since that time, I've done a bit of digging around. The first suspicion was that, perhaps, the NIST had fudged a bit in the WWVB timecode recently, so I manually decoded a few frames and analyzed them: Nothing suspicious there. The next question was if the addition of the BPSK somehow skewed the timing of the TRF's AGC/threshold - but logically, this didn't make sense since the clock *did* set itself exactly ONCE - and it wouldn't have been able to do this at all were this the case. Out of curiosity I poked around on the board and found the trace containing the time code and found that despite the BPSK, its timing was exactly as it should have been: No surprise there. This left the clock itself, so I did what any other Time Nut would do: I built a WWVB simulator. Initially, I set it to a 2010 date - a time that I knew that the clock worked properly. I had two clocks: One that I'd just reset by pulling and replacing the battery while the other had been stuck for a few weeks, not resetting itself nightly as it should. I put both of these in the coupling loops from my WWVB simulator and over the next few days, the recently re-set clock happily synchronized itself while the other one with the 2013 date was still stuck. I then reset that clock and it, too, behaved itself from then on. I then reset the clock on the simulator to a February 2013 date and time. Initially, both clocks reset themselves to the current time and date at their next midnight, but after that, they got stuck, never resetting themselves at night again. So, it appears to be a problem with Broken Sand (e.g. a silicon problem). For the morbidly curious, I have documented my efforts here: http://ka7oei.blogspot.com/**2013/02/did-nist-break-bunch-**of-radio.htmlhttp://ka7oei.blogspot.com/2013/02/did-nist-break-bunch-of-radio.html- The initial testing http://ka7oei.blogspot.com/**2013/03/yes-nist-did-break-** bunch-of-radio.htmlhttp://ka7oei.blogspot.com/2013/03/yes-nist-did-break-bunch-of-radio.html- The testing with the WWVB simulator 73, Clint KA7OEI __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://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 Clocks don't sync anymore (revisited)
Hi So far all the WWVB stuff is running here. That includes my Casio wristwatch. I admit that this thread convinced me to actually check it…. Bob On Mar 20, 2013, at 2:34 AM, Bill S bilt...@gmail.com 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. Bill_S W2FMA On 3/19/2013 5:29 PM, paul swed wrote: Funny you bring this up. I am just noticing a sharp clock that I always use and it has been accurate. But it did not flip with the time change this time and though it says its locked its off by 45 seconds slow. Yet a lacross clock across the room seems to be on second wise but never flipped with the time change. As I say its just becoming apparent. Regards Paul WB8TSL On Tue, Mar 19, 2013 at 4:55 PM, Clint Turner tur...@ussc.com wrote: A few weeks ago I posted a question/comment about some of my WWVB-based Atomic clocks no longer setting themselves properly. These two clocks, SkyScan #86716, would show the symbol indicating that they had set themselves, but their time was drifting away from UTC. Interestingly, they *would* set themselves exactly once upon installation of the battery, but never again. Since that time, I've done a bit of digging around. The first suspicion was that, perhaps, the NIST had fudged a bit in the WWVB timecode recently, so I manually decoded a few frames and analyzed them: Nothing suspicious there. The next question was if the addition of the BPSK somehow skewed the timing of the TRF's AGC/threshold - but logically, this didn't make sense since the clock *did* set itself exactly ONCE - and it wouldn't have been able to do this at all were this the case. Out of curiosity I poked around on the board and found the trace containing the time code and found that despite the BPSK, its timing was exactly as it should have been: No surprise there. This left the clock itself, so I did what any other Time Nut would do: I built a WWVB simulator. Initially, I set it to a 2010 date - a time that I knew that the clock worked properly. I had two clocks: One that I'd just reset by pulling and replacing the battery while the other had been stuck for a few weeks, not resetting itself nightly as it should. I put both of these in the coupling loops from my WWVB simulator and over the next few days, the recently re-set clock happily synchronized itself while the other one with the 2013 date was still stuck. I then reset that clock and it, too, behaved itself from then on. I then reset the clock on the simulator to a February 2013 date and time. Initially, both clocks reset themselves to the current time and date at their next midnight, but after that, they got stuck, never resetting themselves at night again. So, it appears to be a problem with Broken Sand (e.g. a silicon problem). For the morbidly curious, I have documented my efforts here: http://ka7oei.blogspot.com/**2013/02/did-nist-break-bunch-**of-radio.htmlhttp://ka7oei.blogspot.com/2013/02/did-nist-break-bunch-of-radio.html- The initial testing http://ka7oei.blogspot.com/**2013/03/yes-nist-did-break-** bunch-of-radio.htmlhttp://ka7oei.blogspot.com/2013/03/yes-nist-did-break-bunch-of-radio.html- The testing with the WWVB simulator 73, Clint KA7OEI __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://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 Clocks don't sync anymore (revisited)
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? best, Herbert http://www.nist.gov/pml/div688/grp40/wwvb.cfm Bill_S W2FMA On 3/19/2013 5:29 PM, paul swed wrote: Funny you bring this up. I am just noticing a sharp clock that I always use and it has been accurate. But it did not flip with the time change this time and though it says its locked its off by 45 seconds slow. Yet a lacross clock across the room seems to be on second wise but never flipped with the time change. As I say its just becoming apparent. Regards Paul WB8TSL On Tue, Mar 19, 2013 at 4:55 PM, Clint Turner tur...@ussc.com wrote: A few weeks ago I posted a question/comment about some of my WWVB-based Atomic clocks no longer setting themselves properly. These two clocks, SkyScan #86716, would show the symbol indicating that they had set themselves, but their time was drifting away from UTC. Interestingly, they *would* set themselves exactly once upon installation of the battery, but never again. Since that time, I've done a bit of digging around. The first suspicion was that, perhaps, the NIST had fudged a bit in the WWVB timecode recently, so I manually decoded a few frames and analyzed them: Nothing suspicious there. The next question was if the addition of the BPSK somehow skewed the timing of the TRF's AGC/threshold - but logically, this didn't make sense since the clock *did* set itself exactly ONCE - and it wouldn't have been able to do this at all were this the case. Out of curiosity I poked around on the board and found the trace containing the time code and found that despite the BPSK, its timing was exactly as it should have been: No surprise there. This left the clock itself, so I did what any other Time Nut would do: I built a WWVB simulator. Initially, I set it to a 2010 date - a time that I knew that the clock worked properly. I had two clocks: One that I'd just reset by pulling and replacing the battery while the other had been stuck for a few weeks, not resetting itself nightly as it should. I put both of these in the coupling loops from my WWVB simulator and over the next few days, the recently re-set clock happily synchronized itself while the other one with the 2013 date was still stuck. I then reset that clock and it, too, behaved itself from then on. I then reset the clock on the simulator to a February 2013 date and time. Initially, both clocks reset themselves to the current time and date at their next midnight, but after that, they got stuck, never resetting themselves at night again. So, it appears to be a problem with Broken Sand (e.g. a silicon problem). For the morbidly curious, I have documented my efforts here: http://ka7oei.blogspot.com/**2013/02/did-nist-break-bunch-**o f-radio.htmlhttp://ka7oei.blogspot.com/2013/02/did-nist-brea k-bunch-of-radio.html- The initial testing http://ka7oei.blogspot.com/**2013/03/yes-nist-did-break-** bunch-of-radio.htmlhttp://ka7oei.blogspot.com/2013/03/yes-ni st-did-break-bunch-of-radio.html- The testing with the WWVB simulator 73, Clint KA7OEI __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailm an/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 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? ___ 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 Clocks don't sync anymore (revisited)
On Wed, Mar 20, 2013 at 11:22:46AM -0400, Chuck Harris wrote: 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? Then you got a problem I guess :) best, Herbert -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? ___ 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 Clocks don't sync anymore (revisited)
Yes I did seriously try to get the sharp unit going last night no luck at all. The Lacrosse seems to be doing well still. I suspect this is NISTs effort to finally and completely get rid of that totally non green power sucking LF wwvb. Lets face it those towers are an eye sore. The property if not burned has more value for houses at least some day. Besides as we all know the only system needed is GPS. Its always available. All of the above very tongue in cheek. Regards Paul WB8TSL On Wed, Mar 20, 2013 at 2:34 AM, Bill S bilt...@gmail.com 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. Bill_S W2FMA On 3/19/2013 5:29 PM, paul swed wrote: Funny you bring this up. I am just noticing a sharp clock that I always use and it has been accurate. But it did not flip with the time change this time and though it says its locked its off by 45 seconds slow. Yet a lacross clock across the room seems to be on second wise but never flipped with the time change. As I say its just becoming apparent. Regards Paul WB8TSL On Tue, Mar 19, 2013 at 4:55 PM, Clint Turner tur...@ussc.com wrote: A few weeks ago I posted a question/comment about some of my WWVB-based Atomic clocks no longer setting themselves properly. These two clocks, SkyScan #86716, would show the symbol indicating that they had set themselves, but their time was drifting away from UTC. Interestingly, they *would* set themselves exactly once upon installation of the battery, but never again. Since that time, I've done a bit of digging around. The first suspicion was that, perhaps, the NIST had fudged a bit in the WWVB timecode recently, so I manually decoded a few frames and analyzed them: Nothing suspicious there. The next question was if the addition of the BPSK somehow skewed the timing of the TRF's AGC/threshold - but logically, this didn't make sense since the clock *did* set itself exactly ONCE - and it wouldn't have been able to do this at all were this the case. Out of curiosity I poked around on the board and found the trace containing the time code and found that despite the BPSK, its timing was exactly as it should have been: No surprise there. This left the clock itself, so I did what any other Time Nut would do: I built a WWVB simulator. Initially, I set it to a 2010 date - a time that I knew that the clock worked properly. I had two clocks: One that I'd just reset by pulling and replacing the battery while the other had been stuck for a few weeks, not resetting itself nightly as it should. I put both of these in the coupling loops from my WWVB simulator and over the next few days, the recently re-set clock happily synchronized itself while the other one with the 2013 date was still stuck. I then reset that clock and it, too, behaved itself from then on. I then reset the clock on the simulator to a February 2013 date and time. Initially, both clocks reset themselves to the current time and date at their next midnight, but after that, they got stuck, never resetting themselves at night again. So, it appears to be a problem with Broken Sand (e.g. a silicon problem). For the morbidly curious, I have documented my efforts here: http://ka7oei.blogspot.com/2013/02/did-nist-break-bunch-*** *of-radio.htmlhttp://ka7oei.blogspot.com/**2013/02/did-nist-break-bunch-**of-radio.html http://ka7oei.**blogspot.com/2013/02/did-nist-** break-bunch-of-radio.htmlhttp://ka7oei.blogspot.com/2013/02/did-nist-break-bunch-of-radio.html- The initial testing http://ka7oei.blogspot.com/2013/03/yes-nist-did-break-**http://ka7oei.blogspot.com/**2013/03/yes-nist-did-break-** bunch-of-radio.htmlhttp://**ka7oei.blogspot.com/2013/03/** yes-nist-did-break-bunch-of-**radio.htmlhttp://ka7oei.blogspot.com/2013/03/yes-nist-did-break-bunch-of-radio.html- The testing with the WWVB simulator 73, Clint KA7OEI ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshtt**ps://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://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-nutshttps://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/**
Re: [time-nuts] WWVB Clocks don't sync anymore (revisited)
Hi Also consider that some of these receivers use a narrowband crystal filter in front of the IC. I doubt they spend a ton of money on the components, so that may not be the world's best crystal in terms of aging. If it ages far enough the receiver simply goes deaf. If it ages a bit less than that, it slices off one sideband much more than the other. That's likely to do all sorts of odd things to it's ability to ignore phase modulation. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Herbert Poetzl Sent: Wednesday, March 20, 2013 10:58 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] WWVB Clocks don't sync anymore (revisited) 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? best, Herbert http://www.nist.gov/pml/div688/grp40/wwvb.cfm Bill_S W2FMA On 3/19/2013 5:29 PM, paul swed wrote: Funny you bring this up. I am just noticing a sharp clock that I always use and it has been accurate. But it did not flip with the time change this time and though it says its locked its off by 45 seconds slow. Yet a lacross clock across the room seems to be on second wise but never flipped with the time change. As I say its just becoming apparent. Regards Paul WB8TSL On Tue, Mar 19, 2013 at 4:55 PM, Clint Turner tur...@ussc.com wrote: A few weeks ago I posted a question/comment about some of my WWVB-based Atomic clocks no longer setting themselves properly. These two clocks, SkyScan #86716, would show the symbol indicating that they had set themselves, but their time was drifting away from UTC. Interestingly, they *would* set themselves exactly once upon installation of the battery, but never again. Since that time, I've done a bit of digging around. The first suspicion was that, perhaps, the NIST had fudged a bit in the WWVB timecode recently, so I manually decoded a few frames and analyzed them: Nothing suspicious there. The next question was if the addition of the BPSK somehow skewed the timing of the TRF's AGC/threshold - but logically, this didn't make sense since the clock *did* set itself exactly ONCE - and it wouldn't have been able to do this at all were this the case. Out of curiosity I poked around on the board and found the trace containing the time code and found that despite the BPSK, its timing was exactly as it should have been: No surprise there. This left the clock itself, so I did what any other Time Nut would do: I built a WWVB simulator. Initially, I set it to a 2010 date - a time that I knew that the clock worked properly. I had two clocks: One that I'd just reset by pulling and replacing the battery while the other had been stuck for a few weeks, not resetting itself nightly as it should. I put both of these in the coupling loops from my WWVB simulator and over the next few days, the recently re-set clock happily synchronized itself while the other one with the 2013 date was still stuck. I then reset that clock and it, too, behaved itself from then on. I then reset the clock on the simulator to a February 2013 date and time. Initially, both clocks reset themselves to the current time and date at their next midnight, but after that, they got stuck, never resetting themselves at night again. So, it appears to be a problem with Broken Sand (e.g. a silicon problem). For the morbidly curious, I have documented my efforts here: http://ka7oei.blogspot.com/**2013/02/did-nist-break-bunch-**o f-radio.htmlhttp://ka7oei.blogspot.com/2013/02/did-nist-brea k-bunch-of-radio.html- The initial testing http://ka7oei.blogspot.com/**2013/03/yes-nist-did-break-** bunch-of-radio.htmlhttp://ka7oei.blogspot.com/2013/03/yes-ni st-did-break-bunch-of-radio.html- The testing with the WWVB simulator 73, Clint KA7OEI __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailm an/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
Re: [time-nuts] WWVB Clocks don't sync anymore (revisited)
Hi Actually given the way the funding formula probably works (number of mom and pop taxpayers directly using the service) WWVB is pretty safe. There aren't very many other NIST services that connect directly to mom and pop. and no, I didn't think up that formula, nor do I believe it's 100% of the funding story for any program. It is indeed part of it. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of paul swed Sent: Wednesday, March 20, 2013 12:03 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] WWVB Clocks don't sync anymore (revisited) Yes I did seriously try to get the sharp unit going last night no luck at all. The Lacrosse seems to be doing well still. I suspect this is NISTs effort to finally and completely get rid of that totally non green power sucking LF wwvb. Lets face it those towers are an eye sore. The property if not burned has more value for houses at least some day. Besides as we all know the only system needed is GPS. Its always available. All of the above very tongue in cheek. Regards Paul WB8TSL On Wed, Mar 20, 2013 at 2:34 AM, Bill S bilt...@gmail.com 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. Bill_S W2FMA On 3/19/2013 5:29 PM, paul swed wrote: Funny you bring this up. I am just noticing a sharp clock that I always use and it has been accurate. But it did not flip with the time change this time and though it says its locked its off by 45 seconds slow. Yet a lacross clock across the room seems to be on second wise but never flipped with the time change. As I say its just becoming apparent. Regards Paul WB8TSL On Tue, Mar 19, 2013 at 4:55 PM, Clint Turner tur...@ussc.com wrote: A few weeks ago I posted a question/comment about some of my WWVB-based Atomic clocks no longer setting themselves properly. These two clocks, SkyScan #86716, would show the symbol indicating that they had set themselves, but their time was drifting away from UTC. Interestingly, they *would* set themselves exactly once upon installation of the battery, but never again. Since that time, I've done a bit of digging around. The first suspicion was that, perhaps, the NIST had fudged a bit in the WWVB timecode recently, so I manually decoded a few frames and analyzed them: Nothing suspicious there. The next question was if the addition of the BPSK somehow skewed the timing of the TRF's AGC/threshold - but logically, this didn't make sense since the clock *did* set itself exactly ONCE - and it wouldn't have been able to do this at all were this the case. Out of curiosity I poked around on the board and found the trace containing the time code and found that despite the BPSK, its timing was exactly as it should have been: No surprise there. This left the clock itself, so I did what any other Time Nut would do: I built a WWVB simulator. Initially, I set it to a 2010 date - a time that I knew that the clock worked properly. I had two clocks: One that I'd just reset by pulling and replacing the battery while the other had been stuck for a few weeks, not resetting itself nightly as it should. I put both of these in the coupling loops from my WWVB simulator and over the next few days, the recently re-set clock happily synchronized itself while the other one with the 2013 date was still stuck. I then reset that clock and it, too, behaved itself from then on. I then reset the clock on the simulator to a February 2013 date and time. Initially, both clocks reset themselves to the current time and date at their next midnight, but after that, they got stuck, never resetting themselves at night again. So, it appears to be a problem with Broken Sand (e.g. a silicon problem). For the morbidly curious, I have documented my efforts here: http://ka7oei.blogspot.com/2013/02/did-nist-break-bunch-*** *of-radio.htmlhttp://ka7oei.blogspot.com/**2013/02/did-nist-break-bunch-**o f-radio.html http://ka7oei.**blogspot.com/2013/02/did-nist-** break-bunch-of-radio.htmlhttp://ka7oei.blogspot.com/2013/02/did-nist-break- bunch-of-radio.html- The initial testing http://ka7oei.blogspot.com/2013/03/yes-nist-did-break-**http://ka7oei.b logspot.com/**2013/03/yes-nist-did-break-** bunch-of-radio.htmlhttp://**ka7oei.blogspot.com/2013/03/** yes-nist-did-break-bunch-of-**radio.htmlhttp://ka7oei.blogspot.com/2013/03/ yes-nist-did-break-bunch-of-radio.html- The testing with the WWVB simulator 73, Clint KA7OEI ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin
Re: [time-nuts] WWVB Clocks don't sync anymore (revisited)
Have you tried to put BPSK through a narrow band filter and looked at the envelope at the output? -John == Hi Also consider that some of these receivers use a narrowband crystal filter in front of the IC. I doubt they spend a ton of money on the components, so that may not be the world's best crystal in terms of aging. If it ages far enough the receiver simply goes deaf. If it ages a bit less than that, it slices off one sideband much more than the other. That's likely to do all sorts of odd things to it's ability to ignore phase modulation. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Herbert Poetzl Sent: Wednesday, March 20, 2013 10:58 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] WWVB Clocks don't sync anymore (revisited) 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? best, Herbert http://www.nist.gov/pml/div688/grp40/wwvb.cfm Bill_S W2FMA On 3/19/2013 5:29 PM, paul swed wrote: Funny you bring this up. I am just noticing a sharp clock that I always use and it has been accurate. But it did not flip with the time change this time and though it says its locked its off by 45 seconds slow. Yet a lacross clock across the room seems to be on second wise but never flipped with the time change. As I say its just becoming apparent. Regards Paul WB8TSL On Tue, Mar 19, 2013 at 4:55 PM, Clint Turner tur...@ussc.com wrote: A few weeks ago I posted a question/comment about some of my WWVB-based Atomic clocks no longer setting themselves properly. These two clocks, SkyScan #86716, would show the symbol indicating that they had set themselves, but their time was drifting away from UTC. Interestingly, they *would* set themselves exactly once upon installation of the battery, but never again. Since that time, I've done a bit of digging around. The first suspicion was that, perhaps, the NIST had fudged a bit in the WWVB timecode recently, so I manually decoded a few frames and analyzed them: Nothing suspicious there. The next question was if the addition of the BPSK somehow skewed the timing of the TRF's AGC/threshold - but logically, this didn't make sense since the clock *did* set itself exactly ONCE - and it wouldn't have been able to do this at all were this the case. Out of curiosity I poked around on the board and found the trace containing the time code and found that despite the BPSK, its timing was exactly as it should have been: No surprise there. This left the clock itself, so I did what any other Time Nut would do: I built a WWVB simulator. Initially, I set it to a 2010 date - a time that I knew that the clock worked properly. I had two clocks: One that I'd just reset by pulling and replacing the battery while the other had been stuck for a few weeks, not resetting itself nightly as it should. I put both of these in the coupling loops from my WWVB simulator and over the next few days, the recently re-set clock happily synchronized itself while the other one with the 2013 date was still stuck. I then reset that clock and it, too, behaved itself from then on. I then reset the clock on the simulator to a February 2013 date and time. Initially, both clocks reset themselves to the current time and date at their next midnight, but after that, they got stuck, never resetting themselves at night again. So, it appears to be a problem with Broken Sand (e.g. a silicon problem). For the morbidly curious, I have documented my efforts here: http://ka7oei.blogspot.com/**2013/02/did-nist-break-bunch-**o f-radio.htmlhttp://ka7oei.blogspot.com/2013/02/did-nist-brea k-bunch-of-radio.html- The initial testing http://ka7oei.blogspot.com/**2013/03/yes-nist-did-break-** bunch-of-radio.htmlhttp://ka7oei.blogspot.com/2013/03/yes-ni st-did-break-bunch-of-radio.html- The testing with the WWVB simulator 73, Clint KA7OEI __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailm an/listinfo/time-nuts and follow the instructions
Re: [time-nuts] WWVB Clocks don't sync anymore (revisited)
If a clock uses a narrow (high Q)filter, the BPSK may mess up the amplitude response. The Time Code is modulated AM on the carrier. If this is the case, broadening the filter, possibly by adding shunt resistance, might fix the issue. FWIW, -John 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? best, Herbert http://www.nist.gov/pml/div688/grp40/wwvb.cfm Bill_S W2FMA On 3/19/2013 5:29 PM, paul swed wrote: Funny you bring this up. I am just noticing a sharp clock that I always use and it has been accurate. But it did not flip with the time change this time and though it says its locked its off by 45 seconds slow. Yet a lacross clock across the room seems to be on second wise but never flipped with the time change. As I say its just becoming apparent. Regards Paul WB8TSL On Tue, Mar 19, 2013 at 4:55 PM, Clint Turner tur...@ussc.com wrote: A few weeks ago I posted a question/comment about some of my WWVB-based Atomic clocks no longer setting themselves properly. These two clocks, SkyScan #86716, would show the symbol indicating that they had set themselves, but their time was drifting away from UTC. Interestingly, they *would* set themselves exactly once upon installation of the battery, but never again. Since that time, I've done a bit of digging around. The first suspicion was that, perhaps, the NIST had fudged a bit in the WWVB timecode recently, so I manually decoded a few frames and analyzed them: Nothing suspicious there. The next question was if the addition of the BPSK somehow skewed the timing of the TRF's AGC/threshold - but logically, this didn't make sense since the clock *did* set itself exactly ONCE - and it wouldn't have been able to do this at all were this the case. Out of curiosity I poked around on the board and found the trace containing the time code and found that despite the BPSK, its timing was exactly as it should have been: No surprise there. This left the clock itself, so I did what any other Time Nut would do: I built a WWVB simulator. Initially, I set it to a 2010 date - a time that I knew that the clock worked properly. I had two clocks: One that I'd just reset by pulling and replacing the battery while the other had been stuck for a few weeks, not resetting itself nightly as it should. I put both of these in the coupling loops from my WWVB simulator and over the next few days, the recently re-set clock happily synchronized itself while the other one with the 2013 date was still stuck. I then reset that clock and it, too, behaved itself from then on. I then reset the clock on the simulator to a February 2013 date and time. Initially, both clocks reset themselves to the current time and date at their next midnight, but after that, they got stuck, never resetting themselves at night again. So, it appears to be a problem with Broken Sand (e.g. a silicon problem). For the morbidly curious, I have documented my efforts here: http://ka7oei.blogspot.com/**2013/02/did-nist-break-bunch-**o f-radio.htmlhttp://ka7oei.blogspot.com/2013/02/did-nist-brea k-bunch-of-radio.html- The initial testing http://ka7oei.blogspot.com/**2013/03/yes-nist-did-break-** bunch-of-radio.htmlhttp://ka7oei.blogspot.com/2013/03/yes-ni st-did-break-bunch-of-radio.html- The testing with the WWVB simulator 73, Clint KA7OEI __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailm an/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
Re: [time-nuts] WWVB Clocks don't sync anymore (revisited)
I found a note on the SkyScan web site itself that attempts to offer an explanation/excuse as to why some of their clocks no longer synchronize: http://skyscanatomicclocks.com/site/help-my-86715-86730-87315-is-not-catching-the-signal/ This, however, is a BIG red herring. The ONLY change that was made of any significance was the addition of a BPSK component to the carrier. Fortunately, this occurs at the instant that the UTC second begins - when the carrier drops in amplitude - which, in the unlikely event that the ringing of the filtering in these clocks TRF receivers were enough be at all sensitive to BPSK, this phase shift would only go toward assisting them in their immediate detection of the amplitude reduction of the ASK signal transmitted by WWVB. Certainly, by the minimum time at which the carrier amplitude might increase (0.2 seconds for sending a binary 0) the filter has pretty much recovered from the effects of the phase reversal. In programming the WWVB simulation, I also found that the clock's timing was very forgiving - seeming not to care if the timing of these bits was over 100ms out of spec in either direction! (The fact that the clock reliably locked once, after replacing the battery, indicated that it had no trouble with the different modulation.) On these clocks I was able to locate the circuit board trace that connects one epoxy-covered blob (the TRF chip) to the other (the clock itself) and find the demoduated time code which was present after a power-cycle. Even with a fairly poor S/N and the added BPSK, the bandwidth of the TRF is wide enough that time code very nicely matched what WWVB was sending - albeit that it was offset very slightly in time (group delay, etc.) This was easily determined with a dual-trace scope with one channel coming from a strong audio beat note from an LF receiver on a good antenna, and the other channel looking at this logic line. As far as any of these consumer-grade clocks are concerned, there is no modulation present other than the ASK signal and I tend to believe the assertion by the NIST that the addition of the BPSK would be transparent to these receivers. While I don't have an answer for those clocks that flat out refuse to acquire a time signal in the first place (again, even my clocks would lock exactly once after replacing the battery) it would seem clear that these particular units have a problem with their programming in that they don't know what to do with the now-current dates. I've been experimenting on the WWVB simulator with different years to try to more accurately determine the window during which they work, but the initial indications are that the period for which the programming works ranges from somewhere in the late '90s to mid-late '12. As I note on the web page, the 60 kHz WWVB frequency is, unfortunately, fairly close to that on which many switching converters operate - or near its 2nd harmonic and I've found that having an operating CFL or switching wall wart in somewhat close proximity can prevent one of these clocks from acquiring lock - and this is in an area in which the signal's field strength is quite strong, somewhere in the 5 millivolts/meter range! In at least one occasion, I've found that a non-locking clock could be explained by the recent addition of one of these unintentional radiators. 73, Clint KA7OEI ___ 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 Clocks don't sync anymore (revisited)
I also have a SkyScan clock that is claiming to be synced to WWVB, but is slowly drifting off. I've replaced the battery and it synced at least once after DST conversion, Two other WWVB clocks are working as they should. On Tue, Mar 19, 2013 at 1:55 PM, Clint Turner tur...@ussc.com wrote: A few weeks ago I posted a question/comment about some of my WWVB-based Atomic clocks no longer setting themselves properly. These two clocks, SkyScan #86716, would show the symbol indicating that they had set themselves, but their time was drifting away from UTC. Interestingly, they *would* set themselves exactly once upon installation of the battery, but never again. Since that time, I've done a bit of digging around. The first suspicion was that, perhaps, the NIST had fudged a bit in the WWVB timecode recently, so I manually decoded a few frames and analyzed them: Nothing suspicious there. The next question was if the addition of the BPSK somehow skewed the timing of the TRF's AGC/threshold - but logically, this didn't make sense since the clock *did* set itself exactly ONCE - and it wouldn't have been able to do this at all were this the case. Out of curiosity I poked around on the board and found the trace containing the time code and found that despite the BPSK, its timing was exactly as it should have been: No surprise there. This left the clock itself, so I did what any other Time Nut would do: I built a WWVB simulator. Initially, I set it to a 2010 date - a time that I knew that the clock worked properly. I had two clocks: One that I'd just reset by pulling and replacing the battery while the other had been stuck for a few weeks, not resetting itself nightly as it should. I put both of these in the coupling loops from my WWVB simulator and over the next few days, the recently re-set clock happily synchronized itself while the other one with the 2013 date was still stuck. I then reset that clock and it, too, behaved itself from then on. I then reset the clock on the simulator to a February 2013 date and time. Initially, both clocks reset themselves to the current time and date at their next midnight, but after that, they got stuck, never resetting themselves at night again. So, it appears to be a problem with Broken Sand (e.g. a silicon problem). For the morbidly curious, I have documented my efforts here: http://ka7oei.blogspot.com/**2013/02/did-nist-break-bunch-**of-radio.htmlhttp://ka7oei.blogspot.com/2013/02/did-nist-break-bunch-of-radio.html- The initial testing http://ka7oei.blogspot.com/**2013/03/yes-nist-did-break-** bunch-of-radio.htmlhttp://ka7oei.blogspot.com/2013/03/yes-nist-did-break-bunch-of-radio.html- The testing with the WWVB simulator 73, Clint KA7OEI __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://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 Clocks don't sync anymore (revisited) (J. Forster)
Re: WWVB Clocks don't sync anymore (revisited) (J. Forster) As it turns out the batteries in my Radio Shack WWVB alarm clock had died. I replaced them last night around midnight and went off to bed. This morning it has synched up fine. I dissected an identical one of these a while back. It does have a very narrow band single resonator crystal filter. I think the BW was just s few Hz and PSK would turn to AM at the keying rate. Of course on each phase reversal the amplitude out of the filter would go to zero for an instant. Here in East Kansas the WWVB signal from a ferrite rod can be received on my tek 475 with no premap. That is loud. -73 john K6iql -Original Message- From: time-nuts-request time-nuts-requ...@febo.com To: time-nuts time-nuts@febo.com Sent: Wed, Mar 20, 2013 12:29 pm Subject: time-nuts Digest, Vol 104, Issue 70 Send time-nuts mailing list submissions to time-nuts@febo.com To subscribe or unsubscribe via the World Wide Web, visit https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts or, via email, send a message with subject or body 'help' to time-nuts-requ...@febo.com You can reach the person managing the list at time-nuts-ow...@febo.com When replying, please edit your Subject line so it is more specific than Re: Contents of time-nuts digest... Today's Topics: 1. Re: WWVB Clocks don't sync anymore (revisited) (J. Forster) 2. Re: WWVB Clocks don't sync anymore (revisited) (J. Forster) 3. Re: Repair of PRS10 Lamp Assembly (Dr. G?tz Romahn) 4. Re: WWVB Clocks don't sync anymore (revisited) (Clint Turner) 5. Re: Is possible precise 1pps? (Herbert Poetzl) -- Message: 1 Date: Wed, 20 Mar 2013 09:24:12 -0700 (PDT) From: J. Forster j...@quikus.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Subject: Re: [time-nuts] WWVB Clocks don't sync anymore (revisited) Message-ID: 65101.12.6.201.31.1363796652.squir...@popaccts.quikus.com Content-Type: text/plain;charset=iso-8859-1 Have you tried to put BPSK through a narrow band filter and looked at the envelope at the output? -John == Hi Also consider that some of these receivers use a narrowband crystal filter in front of the IC. I doubt they spend a ton of money on the components, so that may not be the world's best crystal in terms of aging. If it ages far enough the receiver simply goes deaf. If it ages a bit less than that, it slices off one sideband much more than the other. That's likely to do all sorts of odd things to it's ability to ignore phase modulation. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Herbert Poetzl Sent: Wednesday, March 20, 2013 10:58 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] WWVB Clocks don't sync anymore (revisited) 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? best, Herbert http://www.nist.gov/pml/div688/grp40/wwvb.cfm Bill_S W2FMA On 3/19/2013 5:29 PM, paul swed wrote: Funny you bring this up. I am just noticing a sharp clock that I always use and it has been accurate. But it did not flip with the time change this time and though it says its locked its off by 45 seconds slow. Yet a lacross clock across the room seems to be on second wise but never flipped with the time change. As I say its just becoming apparent. Regards Paul WB8TSL On Tue, Mar 19, 2013 at 4:55 PM, Clint Turner tur...@ussc.com wrote: A few weeks ago I posted a question/comment about some of my WWVB-based Atomic clocks no longer setting themselves properly. These two clocks, SkyScan #86716, would show the symbol indicating that they had set themselves, but their time was drifting away from UTC. Interestingly, they *would* set themselves exactly once upon installation of the battery, but never again. Since that time, I've done a bit of digging around. The first suspicion was that, perhaps, the NIST had fudged a bit in the WWVB timecode recently, so I manually decoded a few frames and analyzed them: Nothing suspicious there. The next question
Re: [time-nuts] WWVB Clocks don't sync anymore (revisited)
Well I have lost 2 sharps one a while ago and now another that had been working well until dst. Yes they are 4-5 years old but the xtals aren't all that sharp and the gain in the TRF is pretty significant such that the xtal can be off frequency and still work. But the odd thing is there is an antenna symbol and it saying it did sync. Strange. On Wed, Mar 20, 2013 at 1:28 PM, Eric Williams wd6...@earthlink.net wrote: I also have a SkyScan clock that is claiming to be synced to WWVB, but is slowly drifting off. I've replaced the battery and it synced at least once after DST conversion, Two other WWVB clocks are working as they should. On Tue, Mar 19, 2013 at 1:55 PM, Clint Turner tur...@ussc.com wrote: A few weeks ago I posted a question/comment about some of my WWVB-based Atomic clocks no longer setting themselves properly. These two clocks, SkyScan #86716, would show the symbol indicating that they had set themselves, but their time was drifting away from UTC. Interestingly, they *would* set themselves exactly once upon installation of the battery, but never again. Since that time, I've done a bit of digging around. The first suspicion was that, perhaps, the NIST had fudged a bit in the WWVB timecode recently, so I manually decoded a few frames and analyzed them: Nothing suspicious there. The next question was if the addition of the BPSK somehow skewed the timing of the TRF's AGC/threshold - but logically, this didn't make sense since the clock *did* set itself exactly ONCE - and it wouldn't have been able to do this at all were this the case. Out of curiosity I poked around on the board and found the trace containing the time code and found that despite the BPSK, its timing was exactly as it should have been: No surprise there. This left the clock itself, so I did what any other Time Nut would do: I built a WWVB simulator. Initially, I set it to a 2010 date - a time that I knew that the clock worked properly. I had two clocks: One that I'd just reset by pulling and replacing the battery while the other had been stuck for a few weeks, not resetting itself nightly as it should. I put both of these in the coupling loops from my WWVB simulator and over the next few days, the recently re-set clock happily synchronized itself while the other one with the 2013 date was still stuck. I then reset that clock and it, too, behaved itself from then on. I then reset the clock on the simulator to a February 2013 date and time. Initially, both clocks reset themselves to the current time and date at their next midnight, but after that, they got stuck, never resetting themselves at night again. So, it appears to be a problem with Broken Sand (e.g. a silicon problem). For the morbidly curious, I have documented my efforts here: http://ka7oei.blogspot.com/**2013/02/did-nist-break-bunch-**of-radio.html http://ka7oei.blogspot.com/2013/02/did-nist-break-bunch-of-radio.html- The initial testing http://ka7oei.blogspot.com/**2013/03/yes-nist-did-break-** bunch-of-radio.html http://ka7oei.blogspot.com/2013/03/yes-nist-did-break-bunch-of-radio.html- The testing with the WWVB simulator 73, Clint KA7OEI __**_ time-nuts mailing list -- time-nuts@febo.com 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 -- 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 Clocks don't sync anymore (revisited)
Someone pointed out a typo: I wrote model number 86716 where I meant to write 86715 for the SkyScan clock in question. In the linked web pages it is correct, however. 73, Clint KA7OEI Clint Turner wrote: A few weeks ago I posted a question/comment about some of my WWVB-based Atomic clocks no longer setting themselves properly. These two clocks, SkyScan #86716, would show the symbol indicating that they had set themselves, but their time was drifting away from UTC. Interestingly, they *would* set themselves exactly once upon installation of the battery, but never again. Since that time, I've done a bit of digging around. The first suspicion was that, perhaps, the NIST had fudged a bit in the WWVB timecode recently, so I manually decoded a few frames and analyzed them: Nothing suspicious there. The next question was if the addition of the BPSK somehow skewed the timing of the TRF's AGC/threshold - but logically, this didn't make sense since the clock *did* set itself exactly ONCE - and it wouldn't have been able to do this at all were this the case. Out of curiosity I poked around on the board and found the trace containing the time code and found that despite the BPSK, its timing was exactly as it should have been: No surprise there. This left the clock itself, so I did what any other Time Nut would do: I built a WWVB simulator. Initially, I set it to a 2010 date - a time that I knew that the clock worked properly. I had two clocks: One that I'd just reset by pulling and replacing the battery while the other had been stuck for a few weeks, not resetting itself nightly as it should. I put both of these in the coupling loops from my WWVB simulator and over the next few days, the recently re-set clock happily synchronized itself while the other one with the 2013 date was still stuck. I then reset that clock and it, too, behaved itself from then on. I then reset the clock on the simulator to a February 2013 date and time. Initially, both clocks reset themselves to the current time and date at their next midnight, but after that, they got stuck, never resetting themselves at night again. So, it appears to be a problem with Broken Sand (e.g. a silicon problem). For the morbidly curious, I have documented my efforts here: http://ka7oei.blogspot.com/2013/02/did-nist-break-bunch-of-radio.html - The initial testing http://ka7oei.blogspot.com/2013/03/yes-nist-did-break-bunch-of-radio.html - The testing with the WWVB simulator 73, Clint KA7OEI ___ 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 Clocks don't sync anymore (revisited)
Funny you bring this up. I am just noticing a sharp clock that I always use and it has been accurate. But it did not flip with the time change this time and though it says its locked its off by 45 seconds slow. Yet a lacross clock across the room seems to be on second wise but never flipped with the time change. As I say its just becoming apparent. Regards Paul WB8TSL On Tue, Mar 19, 2013 at 4:55 PM, Clint Turner tur...@ussc.com wrote: A few weeks ago I posted a question/comment about some of my WWVB-based Atomic clocks no longer setting themselves properly. These two clocks, SkyScan #86716, would show the symbol indicating that they had set themselves, but their time was drifting away from UTC. Interestingly, they *would* set themselves exactly once upon installation of the battery, but never again. Since that time, I've done a bit of digging around. The first suspicion was that, perhaps, the NIST had fudged a bit in the WWVB timecode recently, so I manually decoded a few frames and analyzed them: Nothing suspicious there. The next question was if the addition of the BPSK somehow skewed the timing of the TRF's AGC/threshold - but logically, this didn't make sense since the clock *did* set itself exactly ONCE - and it wouldn't have been able to do this at all were this the case. Out of curiosity I poked around on the board and found the trace containing the time code and found that despite the BPSK, its timing was exactly as it should have been: No surprise there. This left the clock itself, so I did what any other Time Nut would do: I built a WWVB simulator. Initially, I set it to a 2010 date - a time that I knew that the clock worked properly. I had two clocks: One that I'd just reset by pulling and replacing the battery while the other had been stuck for a few weeks, not resetting itself nightly as it should. I put both of these in the coupling loops from my WWVB simulator and over the next few days, the recently re-set clock happily synchronized itself while the other one with the 2013 date was still stuck. I then reset that clock and it, too, behaved itself from then on. I then reset the clock on the simulator to a February 2013 date and time. Initially, both clocks reset themselves to the current time and date at their next midnight, but after that, they got stuck, never resetting themselves at night again. So, it appears to be a problem with Broken Sand (e.g. a silicon problem). For the morbidly curious, I have documented my efforts here: http://ka7oei.blogspot.com/**2013/02/did-nist-break-bunch-**of-radio.htmlhttp://ka7oei.blogspot.com/2013/02/did-nist-break-bunch-of-radio.html- The initial testing http://ka7oei.blogspot.com/**2013/03/yes-nist-did-break-** bunch-of-radio.htmlhttp://ka7oei.blogspot.com/2013/03/yes-nist-did-break-bunch-of-radio.html- The testing with the WWVB simulator 73, Clint KA7OEI __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://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.
