Re: [time-nuts] New NIST Time Code to Boost Reception for Radio-Controlled Clocks
here is a description how a receiver works for a time signal with very similar modulation http://caxapa.ru/thumbs/417284/Engeler_DCF77.pdf 73 KJ6UHN On 5/31/2014 2:23 PM, paul swed wrote: I had reached out several times to the new wwvb chip maker for this timecode. And though first run chips were available they are not to us unless we want 1000 of them. Also pricing is unclear. That said yes the intent is to receive time. The new chip doesn't easily allow a way to d-psk the signal. Though it can be helpful. Regards Paul WB8TSL On Sat, May 31, 2014 at 4:31 PM, Brooke Clarke wrote: Hi: What are the left two digits telling us? http://www.nist.gov/pml/div688/wwvb-030513.cfm I've emailed John Lowe & James Burrus the above question and for more information about the different transmission modes as well as more information about the hardware shown on the above web page. -- Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html http://www.prc68.com/I/DietNutrition.html ___ 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] Beginner question - unexpected possible jitter in 1 PPS output of Motorola ONCORE UT+ module
I posted here some days ago an admission that I did exactly this by accident once. It is a very hard problem to debug because everything works just fine, except for the very high jitter. So I go looking for noise and what not.The problem was a wrong number of inverters. On Sat, May 31, 2014 at 7:58 PM, Jean-Louis Oneto wrote: > . So if your divider is clocked on the falling edge of the 1PPS, you > can expect a 1 ms jitter... -- Chris Albertson Redondo Beach, California ___ 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] Beginner question - unexpected possible jitter in 1 PPS output of Motorola ONCORE UT+ module
Hello, The UT_Eng_Notes file I have (for the UT, not the UT+) specify: 1PPS Signal Description . 0 to 5 V pulse . Pulse accuracy: - Normal mode: < 130 ns (one sigma) with SA on - Position-hold mode: < 50 ns (one sigma) with SA on . Rise time from 0 to 5 V is approximately 20 to 30 ns with a recommended maximum line loading of 50 pF . 1PPS time mark is synchronous with rising edge of pulse . Pulse width is approximately 200 ms (*± 1 ms*), i.e. the falling edge occurs approximately 200 ms after the rising edge . Pulse can be advanced to account for antenna cable delay using the 1PPS Cable Delay command . Pulse location can be delayed using the 1PPS Offset command to position the pulse at any desired time within the one second window So if your divider is clocked on the falling edge of the 1PPS, you can expect a 1 ms jitter... Regards, Jean-Louis On 31/05/2014 22:02, David Feldman wrote: Picked this project back up this afternoon after couple of weeks, narrowed the problem down but not solved. Refresh: My ONCORE UT+ module appears to have very extreme jitter (on on order of 100 uSec, not nSec random variation between leading edges of successive pulses) in the 1 PPS output. I am using the 1 Hz signal, divided to 0.05 Hz at 50% duty cycle (10 seconds high, 10 seconds low), to gate my frequency counter's reference oscillator back into the same counter running in pulse-count mode so I can adjust the OCXO bias on the counter for calibration. 10 seconds count-up, followed by 10 seconds idle where I can record the measurement, reset the counter, and adjust the OCXO bias. I've now built a simple 1 Hz pulse generator using a 32768 Hz crystal and CD4060 divider. Using that signal instead of the ONCORE UT+, my counter is behaving as expected (that is, each count-up session results in the same result, +/- a few counts as would be expected with a simple 1 PPS signal.) This tells me the gating circuit and interface to the counter's reference output and count input are probably OK. When using the ONCORE UT+, the counts vary by 1 or more from one 10-second capture to the next (each count-up period would total 130,000,000 counts if the ONCORE UT+ was working properly and the reference OCXO was properly adjusted.) I am not yet able to determine why the UT+ 1 PPS signal has such severe jitter. TAC software tells me 7-8 satellites acquired/tracked once cold start has completed (10-15 minutes.) Is there something I'm missing about UT+ care and feeding? There are no RF or switching digital signals close to the UT+ module (the gating circuit is a couple of inches away, both mounted on the same perf board, with common ground and power supply connections. Now that I've ruled out the counter/gating circuit interface, I begin to suspect the UT+ but don't really know what to expect in terms of normal/abnormal operation. Any advice at this point? Thanks, Dave ___ 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] New NIST Time Code to Boost Reception for Radio-Controlled Clocks
Hi The price of the spin isn’t just the cost of the masks. There’s a non-trivial cost involved in the redesign of the chip and the testing that finds the problem. You can indeed do a project run for $5,000 and get usable chips. The same process moved to a single wafer also can give you a few thousand (maybe) of some very expensive dice. If you want a proper mask set and high volume / low cost tooling - it’s not cheap. Bob On May 31, 2014, at 9:08 PM, Jim Lux wrote: > On 5/31/14, 5:48 PM, Bob Camp wrote: >> Hi >> >> A thousand chips at $1 a chip is a very different thing than a thousand >> chips at $100 a chip. The next issue might be that they only have them in >> die form. The issue after that probably is that you really want the version >> 3 (or 9) chips that actually work with all the modulation schemes. I’ve been >> down the road with a number of similar chips that took *many* rev’s before >> they really did what they were intended to do. Many millions of dollars a >> pass times 3 or 6 passes is an whole different world ….. >> >> > > These days, though, the "per spin" cost is substantially lower, and the > number of spins has been reduced, assuming you're forking out the many $M > /year for the design tools. I've been given to understand that an RF ASIC > spin in CMOS (which works up to low microwave frequencies) is around $100k > and would get you a wafer of dice. > > ___ > 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] New NIST Time Code to Boost Reception for Radio-Controlled Clocks
On 5/31/14, 5:48 PM, Bob Camp wrote: Hi A thousand chips at $1 a chip is a very different thing than a thousand chips at $100 a chip. The next issue might be that they only have them in die form. The issue after that probably is that you really want the version 3 (or 9) chips that actually work with all the modulation schemes. I’ve been down the road with a number of similar chips that took *many* rev’s before they really did what they were intended to do. Many millions of dollars a pass times 3 or 6 passes is an whole different world ….. These days, though, the "per spin" cost is substantially lower, and the number of spins has been reduced, assuming you're forking out the many $M /year for the design tools. I've been given to understand that an RF ASIC spin in CMOS (which works up to low microwave frequencies) is around $100k and would get you a wafer of dice. ___ 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] New NIST Time Code to Boost Reception for Radio-Controlled Clocks
Hi A thousand chips at $1 a chip is a very different thing than a thousand chips at $100 a chip. The next issue might be that they only have them in die form. The issue after that probably is that you really want the version 3 (or 9) chips that actually work with all the modulation schemes. I’ve been down the road with a number of similar chips that took *many* rev’s before they really did what they were intended to do. Many millions of dollars a pass times 3 or 6 passes is an whole different world ….. Bob On May 31, 2014, at 5:23 PM, paul swed wrote: > I had reached out several times to the new wwvb chip maker for this > timecode. > And though first run chips were available they are not to us unless we want > 1000 of them. Also pricing is unclear. > That said yes the intent is to receive time. The new chip doesn't easily > allow a way to d-psk the signal. Though it can be helpful. > Regards > Paul > WB8TSL > > > On Sat, May 31, 2014 at 4:31 PM, Brooke Clarke wrote: > >> Hi: >> >> What are the left two digits telling us? >> http://www.nist.gov/pml/div688/wwvb-030513.cfm >> >> I've emailed John Lowe & James Burrus the above question and for more >> information about the different transmission modes as well as more >> information about the hardware shown on the above web page. >> >> -- >> Have Fun, >> >> Brooke Clarke >> http://www.PRC68.com >> http://www.end2partygovernment.com/2012Issues.html >> http://www.prc68.com/I/DietNutrition.html >> >> ___ >> 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] New NIST Time Code to Boost Reception for Radio-Controlled Clocks
At 04:23 PM 5/31/2014, paul swed wrote: And though first run chips were available they are not to us unless we want 1000 of them. Also pricing is unclear. If they don't have distribution set up yet, I can understand 1k min orders...but no samples? That said yes the intent is to receive time. The new chip doesn't easily allow a way to d-psk the signal. Though it can be helpful. Sounds like you might have a datasheet? I'd love to see one. -- newell N5TNL ___ 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] New NIST Time Code to Boost Reception for Radio-Controlled Clocks
I had reached out several times to the new wwvb chip maker for this timecode. And though first run chips were available they are not to us unless we want 1000 of them. Also pricing is unclear. That said yes the intent is to receive time. The new chip doesn't easily allow a way to d-psk the signal. Though it can be helpful. Regards Paul WB8TSL On Sat, May 31, 2014 at 4:31 PM, Brooke Clarke wrote: > Hi: > > What are the left two digits telling us? > http://www.nist.gov/pml/div688/wwvb-030513.cfm > > I've emailed John Lowe & James Burrus the above question and for more > information about the different transmission modes as well as more > information about the hardware shown on the above web page. > > -- > Have Fun, > > Brooke Clarke > http://www.PRC68.com > http://www.end2partygovernment.com/2012Issues.html > http://www.prc68.com/I/DietNutrition.html > > ___ > 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] Beginner question - unexpected possible jitter in 1 PPS output of Motorola ONCORE UT+ module
Check rising/falling edge times, check trigger levels, check signal levels and load. Are you DC or AC coupled. How about power supply noise and grounding? Which edge are you actually triggering on? Is there crosstalk with the Tx line. It is extremely unlikely that there's a problem with the UT+ itself -- this series of Motorola Oncore GPS boards has served the time & frequency community for two decades with no problems, or jitter, or off-by-100us errors. It will be fun to meticulously track down the bug; don't just make it go away and move on. We will all learn from this interesting problem. I'll trade you a perfect UT+ if you give up. At some point we time nuts stop getting excited about what works and delight in what doesn't, and why. /tvb (i5s) > On May 31, 2014, at 3:02 PM, David Feldman wrote: > > > Picked this project back up this afternoon after couple of weeks, narrowed > the problem down but not solved. > > Refresh: My ONCORE UT+ module appears to have very extreme jitter (on on > order of 100 uSec, not nSec random variation between leading edges of > successive pulses) in the 1 PPS output. I am using the 1 Hz signal, divided > to 0.05 Hz at 50% duty cycle (10 seconds high, 10 seconds low), to gate my > frequency counter's reference oscillator back into the same counter running > in pulse-count mode so I can adjust the OCXO bias on the counter for > calibration. 10 seconds count-up, followed by 10 seconds idle where I can > record the measurement, reset the counter, and adjust the OCXO bias. > > I've now built a simple 1 Hz pulse generator using a 32768 Hz crystal and > CD4060 divider. Using that signal instead of the ONCORE UT+, my counter is > behaving as expected (that is, each count-up session results in the same > result, +/- a few counts as would be expected with a simple 1 PPS signal.) > This tells me the gating circuit and interface to the counter's reference > output and count input are probably OK. > > When using the ONCORE UT+, the counts vary by 1 or more from one > 10-second capture to the next (each count-up period would total 130,000,000 > counts if the ONCORE UT+ was working properly and the reference OCXO was > properly adjusted.) > > I am not yet able to determine why the UT+ 1 PPS signal has such severe > jitter. TAC software tells me 7-8 satellites acquired/tracked once cold start > has completed (10-15 minutes.) Is there something I'm missing about UT+ care > and feeding? There are no RF or switching digital signals close to the UT+ > module (the gating circuit is a couple of inches away, both mounted on the > same perf board, with common ground and power supply connections. > > Now that I've ruled out the counter/gating circuit interface, I begin to > suspect the UT+ but don't really know what to expect in terms of > normal/abnormal operation. > > Any advice at this point? > > Thanks, > > Dave > > ___ > 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] Beginner question - unexpected possible jitter in 1 PPS output of Motorola ONCORE UT+ module
Picked this project back up this afternoon after couple of weeks, narrowed the problem down but not solved. Refresh: My ONCORE UT+ module appears to have very extreme jitter (on on order of 100 uSec, not nSec random variation between leading edges of successive pulses) in the 1 PPS output. I am using the 1 Hz signal, divided to 0.05 Hz at 50% duty cycle (10 seconds high, 10 seconds low), to gate my frequency counter's reference oscillator back into the same counter running in pulse-count mode so I can adjust the OCXO bias on the counter for calibration. 10 seconds count-up, followed by 10 seconds idle where I can record the measurement, reset the counter, and adjust the OCXO bias. I've now built a simple 1 Hz pulse generator using a 32768 Hz crystal and CD4060 divider. Using that signal instead of the ONCORE UT+, my counter is behaving as expected (that is, each count-up session results in the same result, +/- a few counts as would be expected with a simple 1 PPS signal.) This tells me the gating circuit and interface to the counter's reference output and count input are probably OK. When using the ONCORE UT+, the counts vary by 1 or more from one 10-second capture to the next (each count-up period would total 130,000,000 counts if the ONCORE UT+ was working properly and the reference OCXO was properly adjusted.) I am not yet able to determine why the UT+ 1 PPS signal has such severe jitter. TAC software tells me 7-8 satellites acquired/tracked once cold start has completed (10-15 minutes.) Is there something I'm missing about UT+ care and feeding? There are no RF or switching digital signals close to the UT+ module (the gating circuit is a couple of inches away, both mounted on the same perf board, with common ground and power supply connections. Now that I've ruled out the counter/gating circuit interface, I begin to suspect the UT+ but don't really know what to expect in terms of normal/abnormal operation. Any advice at this point? Thanks, Dave ___ 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 paper in May 2014 IEEE communications...
Hi We are in a “brave new world” of industry / government interaction. Watching how it plays out with WWVB (through real product) probably will provide a number of people with research topics for years to come. Yes it’s frustrating, a lot of it is as new to them as it is to us. I’m willing to cut them a bit of slack on that basis. Bob On May 31, 2014, at 5:11 PM, Steven Kluck wrote: > I have been able to consistently receive the WWVB phase-modulated data of > what is now being referred to as "Normal Mode" since last summer, using an > air-wound coil antenna, multiple op-amp front end, and a PIC > microcontroller setup that I originally used for receiving the > amplitude-modulated signal. > > I think that Bob Camp brings up a legitimate issue when he writes "I kind > of doubt that the watch and clock guys are going to start the fabs turning > out millions of chips until they can test all the formats." > > One observation has been that data interpretation does not look altogether > simple. With the AM scheme, you could easily find the beginning of a > minute frame, just by looking for two consecutive markers. With the PSK > Normal Mode, each second begins with a 13-bit sync word. Sounds simple > enough, but if you see the sync word pattern, don't jump to any > conclusions, because the pattern will re-occur sometimes at other places > within the same minute frame. It strikes me that when product testers > develop test cases, their work is complicated by all of these "special > cases" some of which will not actually occur until decades from now. > > I also wonder if the introduction of new products has been delayed because > of the seemingly capricious manner in which changes are made to the > broadcast specification. Normally, if portions of a communications > protocol are To Be Determined, we see early versions of specifications > which formally reserve certain areas or aspects that are subject to change, > so that early designers can nonetheless work around them. Who wants to put > a trademark on a product that suddenly ceases to operate when the next > unpredictable format change occurs? (Can you tell that I might be a little > frustrated?) > > I've noticed that instrument manufacturers typically have quality programs > that are useful in establishing the reliability of their products. Such > manufacturers may run into a traceability problem in that the NIST's > coverage by quality programs apparently doesn't currently extend to the > Time and Frequency Division. --Steve > > > > > > On Sat, May 31, 2014 at 8:01 AM, Bob Camp wrote: > >> Hi >> >> Well that’s a bit more information. We seem to be missing the deployment >> schedule on the other new modulation formats. I kind of doubt that the >> watch and clock guys are going to start the fabs turning out millions of >> chips until they can test all the formats. >> >> …… the 100 bps signals looks interesting …. Not real clear how well it >> will do with a <30Hz wide crystal filter. >> >> Bob >> >> >> On May 31, 2014, at 4:14 AM, Tom Van Baak (lab) >> wrote: >> >>> http://tf.boulder.nist.gov/general/pdf/2719.pdf >>> >>> /tvb (i5s) >>> On May 31, 2014, at 1:03 AM, "David I. Emery" >> wrote: Well the actual details of the WWVB modulation and time codes are now published. Was just leafing through some journals while doing some boring system configuration here... IEEE Communications Magazine May 2014 has a paper on page 210 by Yingsi Liang, Oren Eliezer, Dinesh Rajan, John Lowe "WWVB Time Signal Broadcast Format and Multi Mode Receiver" Seems to tell a lot more... -- Dave Emery N1PRE/AE, d...@dieconsulting.com DIE Consulting, Weston, >> Mass 02493 "An empty zombie mind with a forlorn barely readable weatherbeaten 'For Rent' sign still vainly flapping outside on the weed encrusted >> pole - in celebration of what could have been, but wasn't and is not to be now >> either." ___ 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 mailin
Re: [time-nuts] WWVB paper in May 2014 IEEE communications...
I have been able to consistently receive the WWVB phase-modulated data of what is now being referred to as "Normal Mode" since last summer, using an air-wound coil antenna, multiple op-amp front end, and a PIC microcontroller setup that I originally used for receiving the amplitude-modulated signal. I think that Bob Camp brings up a legitimate issue when he writes "I kind of doubt that the watch and clock guys are going to start the fabs turning out millions of chips until they can test all the formats." One observation has been that data interpretation does not look altogether simple. With the AM scheme, you could easily find the beginning of a minute frame, just by looking for two consecutive markers. With the PSK Normal Mode, each second begins with a 13-bit sync word. Sounds simple enough, but if you see the sync word pattern, don't jump to any conclusions, because the pattern will re-occur sometimes at other places within the same minute frame. It strikes me that when product testers develop test cases, their work is complicated by all of these "special cases" some of which will not actually occur until decades from now. I also wonder if the introduction of new products has been delayed because of the seemingly capricious manner in which changes are made to the broadcast specification. Normally, if portions of a communications protocol are To Be Determined, we see early versions of specifications which formally reserve certain areas or aspects that are subject to change, so that early designers can nonetheless work around them. Who wants to put a trademark on a product that suddenly ceases to operate when the next unpredictable format change occurs? (Can you tell that I might be a little frustrated?) I've noticed that instrument manufacturers typically have quality programs that are useful in establishing the reliability of their products. Such manufacturers may run into a traceability problem in that the NIST's coverage by quality programs apparently doesn't currently extend to the Time and Frequency Division. --Steve On Sat, May 31, 2014 at 8:01 AM, Bob Camp wrote: > Hi > > Well that’s a bit more information. We seem to be missing the deployment > schedule on the other new modulation formats. I kind of doubt that the > watch and clock guys are going to start the fabs turning out millions of > chips until they can test all the formats. > > …… the 100 bps signals looks interesting …. Not real clear how well it > will do with a <30Hz wide crystal filter. > > Bob > > > On May 31, 2014, at 4:14 AM, Tom Van Baak (lab) > wrote: > > > http://tf.boulder.nist.gov/general/pdf/2719.pdf > > > > /tvb (i5s) > > > >> On May 31, 2014, at 1:03 AM, "David I. Emery" > wrote: > >> > >> Well the actual details of the WWVB modulation and time > >> codes are now published. > >> > >> Was just leafing through some journals while doing some > >> boring system configuration here... > >> > >> IEEE Communications Magazine May 2014 has a paper on page 210 > >> by Yingsi Liang, Oren Eliezer, Dinesh Rajan, John Lowe > >> > >> "WWVB Time Signal Broadcast Format and Multi Mode Receiver" > >> > >> Seems to tell a lot more... > >> > >> -- > >> Dave Emery N1PRE/AE, d...@dieconsulting.com DIE Consulting, Weston, > Mass 02493 > >> "An empty zombie mind with a forlorn barely readable weatherbeaten > >> 'For Rent' sign still vainly flapping outside on the weed encrusted > pole - in > >> celebration of what could have been, but wasn't and is not to be now > either." > >> > >> ___ > >> 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] New NIST Time Code to Boost Reception for Radio-Controlled Clocks
Hi: What are the left two digits telling us? http://www.nist.gov/pml/div688/wwvb-030513.cfm I've emailed John Lowe & James Burrus the above question and for more information about the different transmission modes as well as more information about the hardware shown on the above web page. -- Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html http://www.prc68.com/I/DietNutrition.html ___ 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 paper in May 2014 IEEE communications...
Hi They tested the modulation format they now are using back in 2013. If they also tested the other formats that was done for a very brief period of time. I would think that knowing the transmission schedule of the various formats would be an important input into the chip’s design. More or less, you want to put it to sleep when the format you are after is off the air. Bob On May 31, 2014, at 2:22 PM, Scott Newell wrote: > At 08:01 AM 5/31/2014, Bob Camp wrote: >> Hi >> >> Well that's a bit more information. We seem to be missing the deployment >> schedule on the other new modulation formats. I kind of doubt that the watch >> and clock guys are going to start the fabs turning out millions of chips >> until they can test all the formats. > > http://www.eversetclocks.com/press > http://www.eversetclocks.com/receivers > > They claim to have shipped samples back in 2013, with production slated for > Q3. I can't find anyone selling them. > > Is anyone recording or decoding the new phase modulation? If so, what are you > using? > > I'm trying to measure WWVB signal quality with an old radio clock tied to a > PC parallel port. Maybe I should ask for a sample of the ES100 or ES200 to > compare. > > More modulation details: > http://www.nist.gov/pml/div688/grp40/upload/NIST-Enhanced-WWVB-Broadcast-Format-1_01-2013-11-06.pdf > > > -- > newell N5TNL > ___ > 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 paper in May 2014 IEEE communications...
At 08:01 AM 5/31/2014, Bob Camp wrote: Hi Well that's a bit more information. We seem to be missing the deployment schedule on the other new modulation formats. I kind of doubt that the watch and clock guys are going to start the fabs turning out millions of chips until they can test all the formats. http://www.eversetclocks.com/press http://www.eversetclocks.com/receivers They claim to have shipped samples back in 2013, with production slated for Q3. I can't find anyone selling them. Is anyone recording or decoding the new phase modulation? If so, what are you using? I'm trying to measure WWVB signal quality with an old radio clock tied to a PC parallel port. Maybe I should ask for a sample of the ES100 or ES200 to compare. More modulation details: http://www.nist.gov/pml/div688/grp40/upload/NIST-Enhanced-WWVB-Broadcast-Format-1_01-2013-11-06.pdf -- newell N5TNL ___ 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] Caveats on Allan Deviation with ultra stable oscillators
On Fri, May 30, 2014 at 3:24 PM, Poul-Henning Kamp wrote: > Always locate your DUTs physically orthogonal to each other. Good point. Of course, if you have more than three in an ensemble then the ensuing hyperdimensional vortex may also cause unexpected cross-coupling. Henry ___ 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 paper in May 2014 IEEE communications...
and here is a more detailed description of a similar signal's demodulation: http://caxapa.ru/thumbs/417284/Engeler_DCF77.pdf On 5/31/2014 1:03 AM, David I. Emery wrote: Well the actual details of the WWVB modulation and time codes are now published. Was just leafing through some journals while doing some boring system configuration here... IEEE Communications Magazine May 2014 has a paper on page 210 by Yingsi Liang, Oren Eliezer, Dinesh Rajan, John Lowe "WWVB Time Signal Broadcast Format and Multi Mode Receiver" Seems to tell a lot more... ___ 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 paper in May 2014 IEEE communications...
Hi I’d say it is a safe bet that they will fiddle the way they do the various modulation formats so that the WWVB wrist watches keep working. It will be interesting to see how they do that with the “fast” modulation. I both want my watch to work and I’d like to see the fast stuff on the air for high(er) resolution timing. Bob On May 31, 2014, at 10:27 AM, Mike Feher wrote: > Wonder what the consequences to my Junghans watch will be? - Regards - Mike > > Mike B. Feher, EOZ Inc. > 89 Arnold Blvd. > Howell, NJ, 07731 > 732-886-5960 office > 908-902-3831 cell > > > -Original Message- > From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On > Behalf Of Tom Van Baak (lab) > Sent: Saturday, May 31, 2014 4:14 AM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] WWVB paper in May 2014 IEEE communications... > > http://tf.boulder.nist.gov/general/pdf/2719.pdf > > /tvb (i5s) > >> On May 31, 2014, at 1:03 AM, "David I. Emery" > wrote: >> >> Well the actual details of the WWVB modulation and time codes are >> now published. >> >> Was just leafing through some journals while doing some boring >> system configuration here... >> >> IEEE Communications Magazine May 2014 has a paper on page 210 by >> Yingsi Liang, Oren Eliezer, Dinesh Rajan, John Lowe >> >> "WWVB Time Signal Broadcast Format and Multi Mode Receiver" >> >> Seems to tell a lot more... >> >> -- >> Dave Emery N1PRE/AE, d...@dieconsulting.com DIE Consulting, Weston, >> Mass 02493 "An empty zombie mind with a forlorn barely readable >> weatherbeaten 'For Rent' sign still vainly flapping outside on the >> weed encrusted pole - in celebration of what could have been, but wasn't > and is not to be now either." >> >> ___ >> 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 paper in May 2014 IEEE communications...
Wonder what the consequences to my Junghans watch will be? - Regards - Mike Mike B. Feher, EOZ Inc. 89 Arnold Blvd. Howell, NJ, 07731 732-886-5960 office 908-902-3831 cell -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Tom Van Baak (lab) Sent: Saturday, May 31, 2014 4:14 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] WWVB paper in May 2014 IEEE communications... http://tf.boulder.nist.gov/general/pdf/2719.pdf /tvb (i5s) > On May 31, 2014, at 1:03 AM, "David I. Emery" wrote: > >Well the actual details of the WWVB modulation and time codes are > now published. > >Was just leafing through some journals while doing some boring > system configuration here... > >IEEE Communications Magazine May 2014 has a paper on page 210 by > Yingsi Liang, Oren Eliezer, Dinesh Rajan, John Lowe > > "WWVB Time Signal Broadcast Format and Multi Mode Receiver" > >Seems to tell a lot more... > > -- > Dave Emery N1PRE/AE, d...@dieconsulting.com DIE Consulting, Weston, > Mass 02493 "An empty zombie mind with a forlorn barely readable > weatherbeaten 'For Rent' sign still vainly flapping outside on the > weed encrusted pole - in celebration of what could have been, but wasn't and is not to be now either." > > ___ > 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] Caveats on Allan Deviation with ultra stable oscillators
will also look better than it really is, and for the same reasons. (Some people have even reported similar behavior with cesium standards, although I don't see how that could happen. There aren't supposed to be any first-order temperature effects in a CBT, and I'd think that any lower-order effects would be way beneath the tube's flicker floor...) The 5061 had problems with microwave field leakage known as the top cover effect (see papers by DeMarchi.) This is at least a possible mechanism for injection locking 5061's. The 5071A has a completely different microwave assembly without leakage problems. The 5071A outputs have very high reverse isolation. Tests showed that there are no detectable systematic environmental effects in the 5071A (whatever ones there are fall below the noise). Rick Karlquist N6RK ___ 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 paper in May 2014 IEEE communications...
Hi Well that’s a bit more information. We seem to be missing the deployment schedule on the other new modulation formats. I kind of doubt that the watch and clock guys are going to start the fabs turning out millions of chips until they can test all the formats. …… the 100 bps signals looks interesting …. Not real clear how well it will do with a <30Hz wide crystal filter. Bob On May 31, 2014, at 4:14 AM, Tom Van Baak (lab) wrote: > http://tf.boulder.nist.gov/general/pdf/2719.pdf > > /tvb (i5s) > >> On May 31, 2014, at 1:03 AM, "David I. Emery" wrote: >> >> Well the actual details of the WWVB modulation and time >> codes are now published. >> >> Was just leafing through some journals while doing some >> boring system configuration here... >> >> IEEE Communications Magazine May 2014 has a paper on page 210 >> by Yingsi Liang, Oren Eliezer, Dinesh Rajan, John Lowe >> >> "WWVB Time Signal Broadcast Format and Multi Mode Receiver" >> >> Seems to tell a lot more... >> >> -- >> Dave Emery N1PRE/AE, d...@dieconsulting.com DIE Consulting, Weston, Mass >> 02493 >> "An empty zombie mind with a forlorn barely readable weatherbeaten >> 'For Rent' sign still vainly flapping outside on the weed encrusted pole - >> in >> celebration of what could have been, but wasn't and is not to be now either." >> >> ___ >> 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] Caveats on Allan Deviation with ultra stable oscillators
In message <5389a141.7050...@rubidium.dyndns.org>, Magnus Danielson writes: >Yeah, there is a whole bunch of environmental effects there. I haven't >mentioned the Stark effect, which is the electrostatic field effect. >See, the list grows longer. > >The closer you look, the more effects you will find. Once you get to turtles it kind of settles down :-) -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] Caveats on Allan Deviation with ultra stable oscillators
On 05/31/2014 12:24 AM, Poul-Henning Kamp wrote: In message <013401cf7c46$31ac3cc0$9504b640$@miles.io>, "John Miles" writes: (Some people have even reported similar behavior with cesium standards, although I don't see how that could happen. There aren't supposed to be any first-order temperature effects in a CBT, and I'd think that any lower-order effects would be way beneath the tube's flicker floor...) One important trick in this area: Always locate your DUTs physically orthogonal to each other. Almost none of our DUTs have 3 axis of symmetry, and therefore most environmental effects are not symmetric with respect to orientation. I noticed this by accident comparing three "identical" OCXO's because I had put one of them in a different orientation than the other two: The environmental noise were much larger between that one and the two other, than between the two co-aligned DUTs. I'm not entirely sure this is relevant for Rb/Cs/H, their environmentals should be attenuated enough for it to not matter. Their physical packages do have a sensitivity to magnetic fields. The mymetal shield should handle most of it. Preferably you should let it stay in the same orientation not to see any shift. Hydrogen masers have a sensitivity to barometric pressure and temperature, as it will deform and thus detune the resonant cavity. This shifts with design, so some is sensitive and others is less sensitive. Rubidium and Cesiums is passive clocks, in that you need to insert a frequency generated from a fly-wheel crystal oscillator. Hydrogen masers exist in both passive and active form. In the active maser it actually outputs a signal. I believe that many of the active masers still use a crystal oscillator for the mix-down and locking. Regardless, while *most* of the environmental effects of that crystal oscillator is being canceled by the loop to the atomic reference, for all passive masers it's traditionally a frequency comparison and phase stability depends on how accurate phase deviation is being captured. Most time it is a bit crude detection which works better for frequency than phase. Cesium was selected because it had the second best insensitivity to magnetic fields, but was believed to be easier to work with and thus easier to reproduce. If the choice would have been different we would all be comparing our Thallium-beams and then some of us would be poor enough only to have cesium beams. The basis of selection has shifted, because since we have invented C-field servo to reduce the C-field effect. The means of detection now include lasers, which allows good efficiency. We can also do selective laser pumping which means we don't have to dump half the beam, increasing the signal to noise right there. We can do laser cooling and significantly remove a whole bunch of shifts due to temperature, doppler etc. We can then bounce a ball of atoms up and down a tube, removing the two-cavity systematic shift as well as making the observation time much longer. By cooling down the tube we can then remove the black body temperature shift of frequency. Yeah, there is a whole bunch of environmental effects there. I haven't mentioned the Stark effect, which is the electrostatic field effect. See, the list grows longer. The closer you look, the more effects you will find. 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] Caveats on Allan Deviation with ultra stable oscillators
John, On 05/30/2014 10:31 PM, John Miles wrote: I usually don't use drift removal as I want to see the effects of drift! The effects of oscillators locking together are very apparent on both the phase and AD plots when using a DMTD system. There was no indications of such locking! My point was that if you are measuring ultrastable Quartz oscillators against each other the AD at the higher Tau will not reflect the true stability of the oscillators. Well, it will reflect the true stability if they're not exposed to the same drift stimuli, right? Neglecting shared long-term aging trends, they should both end up in random-walk territory over the long run. Otherwise, if you run the two oscillators in open air in the same room or even the same building, then they will respond similarly to HVAC cycles, diurnal cycles, and whatever other environmental changes are common to both. That will make their ADEV look better than reality when you measure them against each other. Indeed. Another way to view it is that you can that way consider it as a cancellation of those factors so you know how the noise performance behaves, which is what ADEV is all about. That may not be the best choice for other measures. It doesn't mean the long-term ADEV is necessarily invalid as a statistic, just that you probably haven't eliminated all of the common-mode influences. To the extent the two oscillators drift independently, the ADEV measurement is valid. For that matter, the isolation amps in your DMTD are also exposed to the same environment. Their residual phase tempco should be much better than any quartz oscillator, but if they're worse for some reason, they may dominate the long-term measurement. And of course, if you don't have enough isolation, you could be injection-locking the OCXOs in a really low bandwidth (days, perhaps). Shared power supply leads can also induce entrainment -- or even separate power supplies, if you run the leads right next to each other. Some of the Wenzel ULNs seem to be susceptible to this if you don't add bypassing at their power terminals. Only a Maser or high performance Rubidium (HP5065A) will reveal the true behavior. True, because they aren't as sensitive to environmental effects. But if you benchmark two nearby 5065As or masers carefully enough, their long-term ADEV will also look better than it really is, and for the same reasons. (Some people have even reported similar behavior with cesium standards, although I don't see how that could happen. There aren't supposed to be any first-order temperature effects in a CBT, and I'd think that any lower-order effects would be way beneath the tube's flicker floor...) Cesiums and rubidiums is indirectly sensitive as it takes time for the loop to track in changes in the OCXOs frequency. This process isn't phase accurate, so it could creep in phase as a result of environmental changes. Depending on the clock, different amount of work have been made to handle this. However, the differences in ADEV here is due to environmental effects, and they should not be measured in the ADEV context at all. ADEV is about to measure the random noise forms. Systematic effects such as environmental sensitivity is noise to that measurement. There are other measurements better aimed at such deviations. So, when you have cancellation of long term systematic effects you are in fact measuring a trued ADEV. Systematic effects affecting the phase (or frequency) should be separated and presented separately to the ADEV. They should then be canceled out of the measurement data that you make an ADEV plot on. In the end of the day, there is an overbelief of what works well in an ADEV plot. 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 paper in May 2014 IEEE communications...
http://tf.boulder.nist.gov/general/pdf/2719.pdf /tvb (i5s) > On May 31, 2014, at 1:03 AM, "David I. Emery" wrote: > >Well the actual details of the WWVB modulation and time > codes are now published. > >Was just leafing through some journals while doing some > boring system configuration here... > >IEEE Communications Magazine May 2014 has a paper on page 210 > by Yingsi Liang, Oren Eliezer, Dinesh Rajan, John Lowe > > "WWVB Time Signal Broadcast Format and Multi Mode Receiver" > >Seems to tell a lot more... > > -- > Dave Emery N1PRE/AE, d...@dieconsulting.com DIE Consulting, Weston, Mass > 02493 > "An empty zombie mind with a forlorn barely readable weatherbeaten > 'For Rent' sign still vainly flapping outside on the weed encrusted pole - in > celebration of what could have been, but wasn't and is not to be now either." > > ___ > 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] WWVB paper in May 2014 IEEE communications...
Well the actual details of the WWVB modulation and time codes are now published. Was just leafing through some journals while doing some boring system configuration here... IEEE Communications Magazine May 2014 has a paper on page 210 by Yingsi Liang, Oren Eliezer, Dinesh Rajan, John Lowe "WWVB Time Signal Broadcast Format and Multi Mode Receiver" Seems to tell a lot more... -- Dave Emery N1PRE/AE, d...@dieconsulting.com DIE Consulting, Weston, Mass 02493 "An empty zombie mind with a forlorn barely readable weatherbeaten 'For Rent' sign still vainly flapping outside on the weed encrusted pole - in celebration of what could have been, but wasn't and is not to be now either." ___ 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] Caveats on Allan Deviation with ultra stable oscillators
> Always locate your DUTs physically orthogonal to each other. Unless you have 3 clocks. (and everybody knows what happens if you only have 2) >From an old time-nuts message (Mar, 2009) > Allied to this discussion is the Loomis effect, discovered by the > American millionaire who had three Shortt clocks running in his > basement. They synchronised unless aligned at 120 degrees to each > other. I wonder weather they were shaking the bedrock, or maybe the > gravitational attraction between the 10 kg pendulums may have > synchronised them. (See "Tuxedo Park" by Jennet Conant) He qualified > as the first time nut. It's on page 67-68. Google for >Tuxedo-Park Shortt< gets a hit in books.google.com at page 65 which is the start of the coverage of Shortt clocks. That was long before eBay. :) -- 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.
