Re: [time-nuts] KD2BD WWVB receiver/decoder in QEX
By using the NE5532 ICs I have an operational KD2BD wwvb receiver and it has just locked for the first time. Made a few other changes like the vco loop chip is a TLE2071. Thats because it was available much like the article. I also used a PTI 10 MHz oscillator. A nice unit picked up at a flea market so really keeping with the whats available mode. I built only the elements needed to lock the oscillator. Thats still a lot of stuff. There is room to add more pieces if needed. No need for the microprocessor yet. WWVB is being itself tonight. I think MSF is doing a great job of interfering. Happy Thanks giving to everyone. Regards Paul WB8TSL On Mon, Nov 23, 2015 at 7:41 PM, paul swed wrote: > Charles great suggestion on the NE5532. Just bread boarded the first > section of the receiver very quickly and the component values work as is. > Thats also as it should be. I need to do a noise check tomorrow but it > appears I can heat up the ole soldering iron and build quite a bit of the > receiver. > Ah the smell of burning insulation and flux in the evening. > Regards > Paul WB8TSL > > On Mon, Nov 23, 2015 at 1:28 PM, paul swed wrote: > >> Charles I did see the slew rates and bandwidth and came to the conclusion >> those were not issues. Thats why I will build up a test board pretty >> quickly to confirm the component values still work. They should. It also >> means I do not need to wait for the LM873s to showup. Lots can be wired >> without the LMC6484s. >> Regards >> Paul >> WB8TSL >> >> On Mon, Nov 23, 2015 at 12:16 PM, Charles Steinmetz < >> csteinm...@yandex.com> wrote: >> >>> Paul wrote: >>> >>> post down conversion to 10 Khz I was scratching my head as to why not the TL08X series. >>> >>> Input voltage noise. Unless you need the low input current of the FET >>> part, there is no need to take the noise hit. If you *do* need the low >>> input current, there are 4 or 5 generations of FET-input opamps that are >>> all far superior to the TL0xx parts. Take a look at the OPA134/2134/4134, >>> for example. (I haven't used TL0xx opamps since the '70s.) >>> >>> BTW: I suggested using NE5532s instead of LM387s and said they were >>> better in every way. Comparing the LM387 to the NE5532, one might notice >>> that the bandwidth spec of the 5532 is lower (10MHz) than that of the 387 >>> (15MHz). But what is important for most applications is not the >>> small-signal BW, it is the power BW (full-output BW), which depends on the >>> slew rate, not on the SSBW. The 5532's 9v/uS slew rate supports a PBW of >>> 140kHz, while the 387's PBW is only 75kHz (S/R is not stated). (This tells >>> us two things -- first, that the 387's slew rate must be <5v/uS; and >>> second, that the 387 has less phase margin than the 5532.) >>> >>> >>> Best regards, >>> >>> Charles >>> >>> >>> ___ >>> 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] KD2BD WWVB receiver/decoder in QEX
Charles great suggestion on the NE5532. Just bread boarded the first section of the receiver very quickly and the component values work as is. Thats also as it should be. I need to do a noise check tomorrow but it appears I can heat up the ole soldering iron and build quite a bit of the receiver. Ah the smell of burning insulation and flux in the evening. Regards Paul WB8TSL On Mon, Nov 23, 2015 at 1:28 PM, paul swed wrote: > Charles I did see the slew rates and bandwidth and came to the conclusion > those were not issues. Thats why I will build up a test board pretty > quickly to confirm the component values still work. They should. It also > means I do not need to wait for the LM873s to showup. Lots can be wired > without the LMC6484s. > Regards > Paul > WB8TSL > > On Mon, Nov 23, 2015 at 12:16 PM, Charles Steinmetz > wrote: > >> Paul wrote: >> >> post down conversion to 10 Khz I was scratching my head as to why not >>> the TL08X series. >>> >> >> Input voltage noise. Unless you need the low input current of the FET >> part, there is no need to take the noise hit. If you *do* need the low >> input current, there are 4 or 5 generations of FET-input opamps that are >> all far superior to the TL0xx parts. Take a look at the OPA134/2134/4134, >> for example. (I haven't used TL0xx opamps since the '70s.) >> >> BTW: I suggested using NE5532s instead of LM387s and said they were >> better in every way. Comparing the LM387 to the NE5532, one might notice >> that the bandwidth spec of the 5532 is lower (10MHz) than that of the 387 >> (15MHz). But what is important for most applications is not the >> small-signal BW, it is the power BW (full-output BW), which depends on the >> slew rate, not on the SSBW. The 5532's 9v/uS slew rate supports a PBW of >> 140kHz, while the 387's PBW is only 75kHz (S/R is not stated). (This tells >> us two things -- first, that the 387's slew rate must be <5v/uS; and >> second, that the 387 has less phase margin than the 5532.) >> >> >> Best regards, >> >> Charles >> >> >> ___ >> 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] KD2BD WWVB receiver/decoder in QEX
Charles I did see the slew rates and bandwidth and came to the conclusion those were not issues. Thats why I will build up a test board pretty quickly to confirm the component values still work. They should. It also means I do not need to wait for the LM873s to showup. Lots can be wired without the LMC6484s. Regards Paul WB8TSL On Mon, Nov 23, 2015 at 12:16 PM, Charles Steinmetz wrote: > Paul wrote: > > post down conversion to 10 Khz I was scratching my head as to why not >> the TL08X series. >> > > Input voltage noise. Unless you need the low input current of the FET > part, there is no need to take the noise hit. If you *do* need the low > input current, there are 4 or 5 generations of FET-input opamps that are > all far superior to the TL0xx parts. Take a look at the OPA134/2134/4134, > for example. (I haven't used TL0xx opamps since the '70s.) > > BTW: I suggested using NE5532s instead of LM387s and said they were > better in every way. Comparing the LM387 to the NE5532, one might notice > that the bandwidth spec of the 5532 is lower (10MHz) than that of the 387 > (15MHz). But what is important for most applications is not the > small-signal BW, it is the power BW (full-output BW), which depends on the > slew rate, not on the SSBW. The 5532's 9v/uS slew rate supports a PBW of > 140kHz, while the 387's PBW is only 75kHz (S/R is not stated). (This tells > us two things -- first, that the 387's slew rate must be <5v/uS; and > second, that the 387 has less phase margin than the 5532.) > > > Best regards, > > Charles > > > ___ > 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] KD2BD WWVB receiver/decoder in QEX
Paul wrote: post down conversion to 10 Khz I was scratching my head as to why not the TL08X series. Input voltage noise. Unless you need the low input current of the FET part, there is no need to take the noise hit. If you *do* need the low input current, there are 4 or 5 generations of FET-input opamps that are all far superior to the TL0xx parts. Take a look at the OPA134/2134/4134, for example. (I haven't used TL0xx opamps since the '70s.) BTW: I suggested using NE5532s instead of LM387s and said they were better in every way. Comparing the LM387 to the NE5532, one might notice that the bandwidth spec of the 5532 is lower (10MHz) than that of the 387 (15MHz). But what is important for most applications is not the small-signal BW, it is the power BW (full-output BW), which depends on the slew rate, not on the SSBW. The 5532's 9v/uS slew rate supports a PBW of 140kHz, while the 387's PBW is only 75kHz (S/R is not stated). (This tells us two things -- first, that the 387's slew rate must be <5v/uS; and second, that the 387 has less phase margin than the 5532.) Best regards, Charles ___ 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] KD2BD WWVB receiver/decoder in QEX
Paul wrote: It appears that the Chinese sight has the lmc6484 and LM387n at reasonable prices for small quantities. Most likely will order from there. No need to buy likely counterfeit parts on ebay. The LMC6484 is an active-status part, available in both DIP and SOIC from all major distributors including Mouser, Digi-Key, Arrow, and Avnet (the DIP may be EOL, but is still in stock at distributors). The LM387 is a nothing-special, first-generation "low noise" dual opamp. Its dubious claim to fame is that it does not use the industry-standard dual opamp pinout. But since there are no boards available, that wouldn't seem to make any difference. The ubiquitous NE5532, available everywhere, is better in every way, with the standard pinout. Or do like the author did and use whatever low-ish noise dual opamps you have in *your* junk box. The PIC16F88 and DS232A are active-status parts, available from Microchip and Maxim distributors, respectively. It seems like a LOT of circuitry to do what really is a pretty simple job, though. Best regards, Charles ___ 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] KD2BD WWVB receiver/decoder in QEX
On Sun, 22 Nov 2015 21:47:42 -0500 Bob Camp wrote: > We have yet to see how well the new modulation format on WWVB helps. As I have written before, it does not. See: https://www.febo.com/pipermail/time-nuts/2013-July/078098.html https://www.febo.com/pipermail/time-nuts/2013-July/078113.html Attila Kinali -- It is upon moral qualities that a society is ultimately founded. All the prosperity and technological sophistication in the world is of no use without that foundation. -- Miss Matheson, The Diamond Age, Neil Stephenson ___ 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] KD2BD WWVB receiver/decoder in QEX
On Sun, 22 Nov 2015 13:05:53 -0800 Hal Murray wrote: > > I___d have to guess that the PLL would behave better given a 60 kHz > > reference > > rather than a 1 Hz one. But how stable is that 60 kHz reference after going > > through, what, a thousand miles of ionosphere or so? > > One of the reasons for using 60 kHz is to avoid the ionosphere. If you > measure the propagation delay, it should be stable. It is anything but stable, as other people have already written. I have seen graphs for DCF77 that show "jumps" of 200-300us around sunrise and sunset. Unfortunately, I cannot find any of them. The only reliable data I could find is in [1] which shows uncertainties of a couple of us during the day and close to +/-50us during the night for a 273km distance. Attila Kinali [1] "Time dissemination via the LF transmitter DCF77 using a pseudo-random phase-shift keying of the carrier", by Hetzel, 1987 http://remco.tk/handig/DCFp.pdf -- It is upon moral qualities that a society is ultimately founded. All the prosperity and technological sophistication in the world is of no use without that foundation. -- Miss Matheson, The Diamond Age, Neil Stephenson ___ 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] KD2BD WWVB receiver/decoder in QEX
Charles it is a lot of circuitry. But if you want just frequency out then lots of stuff drops out. Since I have experimented with much of this already I will do the reduced versions. There is no need for the PIC, the +- 45 degree chager in the front end, numbers of dividers, output selectors, analog detection, of the old time code etc. The one thing I noticed about the LM837n was that its gain bandwidth products was at least 2-3 X a typical tl084 as an example so a bit better for 60 KHz. Really like your suggestion of the NE5532. Have quite few of those will take a look to see what the implications may be. Also post down conversion to 10 Khz I was scratching my head as to why not the TL08X series. Still a good job and glad it was shared. Regards Paul WB8TSL On Mon, Nov 23, 2015 at 5:02 AM, Charles Steinmetz wrote: > Paul wrote: > > It appears that the Chinese sight has the lmc6484 and LM387n at reasonable >> prices for small quantities. Most likely will order from there. >> > > No need to buy likely counterfeit parts on ebay. The LMC6484 is an > active-status part, available in both DIP and SOIC from all major > distributors including Mouser, Digi-Key, Arrow, and Avnet (the DIP may be > EOL, but is still in stock at distributors). The LM387 is a > nothing-special, first-generation "low noise" dual opamp. Its dubious > claim to fame is that it does not use the industry-standard dual opamp > pinout. But since there are no boards available, that wouldn't seem to > make any difference. The ubiquitous NE5532, available everywhere, is > better in every way, with the standard pinout. Or do like the author did > and use whatever low-ish noise dual opamps you have in *your* junk box. > > The PIC16F88 and DS232A are active-status parts, available from Microchip > and Maxim distributors, respectively. > > It seems like a LOT of circuitry to do what really is a pretty simple job, > though. > > Best regards, > > Charles > > > > ___ > 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] KD2BD WWVB receiver/decoder in QEX
Thanks Bill I had not looked at the date of the latest bulletin just that it was still available. I suspect the major use now is the timecode. Alan G3NYK - Original Message - From: "Bill Byrom" To: Sent: Monday, November 23, 2015 12:12 AM Subject: Re: [time-nuts] KD2BD WWVB receiver/decoder in QEX The last NPL MSF Bulletin showing their errors was over 4 years ago: http://resource.npl.co.uk/time/bulletins/bulletin_archive.html http://www.npl.co.uk/science-technology/time-frequency/products-and-services/time/msf-radio-time-signal The error at a receiver over an interval of a couple of days is nearly completely due to propagation effects. The variations in propagation delay far exceed the error in transmitter frequency/phase control unless there are large changes in the local weather at the transmitter site. The phase of LF signals at 60 kHz is affected by the effective height of the ionosphere, which forms a 60 kHz waveguide with the Earth's surface. Unless you are very close to the transmitter, the amplitude and phase of the received signal change significantly through each 24 hour period. WWVB clocks should always measure the signal during the dark path (when the propagation path between Ft Collins CO and your location is fully dark), since that is when the signal is strongest and tends to have a more stable phase. WWVB clocks can get UTC with an uncertainty of about 100 microseconds, according to NIST: http://www.nist.gov/pml/div688/grp40/wwvb.cfm -- Bill Byrom N5BB On Sun, Nov 22, 2015, at 04:16 PM, Alan Melia wrote: Hi Bob I have just realised that MSF may work diffently?? The Anthorn signal is monitored by NPL at Teddington, West of London and frequency off-sets twice a day are published in parts in 10^12 on their web-site.involving lot of averaging I think. They do not recommend using the signal after dark. You certainly could predict roughly the the skywave phase change during the day and the variation as the sun angle changes on the path over the year. It gets more difficult if there are flares or geomagnetic storms. If two independent stations at slightly different distances collect information it could be corrected even more accurately. The same ionospheric problem occurs of course with Loran, and the now closed Decca system.. Alan G3NYK - Original Message - From: "Bob Camp" To: "Nick Sayer" ; "Discussion of precise time and frequency measurement" Sent: Sunday, November 22, 2015 7:34 PM Subject: Re: [time-nuts] KD2BD WWVB receiver/decoder in QEX Hi The most basic gotcha with WWVB is that propagation can (and does) shift the carrier more than a full cycle over the course of a day. That’s at 60 KHz, so one cycle is a lot (as in 16.666 ppm). Even at one second with a not so great receiver and a poor antenna, GPS should give you ~0.01 ppm. Right up front, you have a bit of a problem. (Yes I’m mixing measurements in that comparison, but the point is still valid). What I keep wondering is - There is no big mystery about the WWVB transmitter's location. You likely know your own location as well. Part of demodulating the data gives you day of the year. From that you can figure out some of the basics of the propagation effects (sunrise is at X:XX sunset is at … etc). You also could grab stuff like weather data fairly easily (no idea if that actually helps). If you fit out the basic propagation impacts, WWVB could get a lot better. At the very least, you would know when to ignore the signal. So yes, you could do better today than they could back in the good old days in terms of the propagation coarse effects. Unfortunately, there also is data on 24 hour comparisons of WWVB carrier (same time of day, one day apart). If you pick your time right (noon or midnight), the variable propagation can be reduced quite a bit. Based on that data, you are doing well at 100 ppt over 24 hours. Might the new modulation help that by 10X? ..maybe. GPS over a 24 hour period should be giving you something in the 0.1 to 0.01 ppt range (same sort of pick a likely stable ionosphere time slot and compare). Does that make a WWVB device un-interesting? Not by any means. If you stretch out the time, both systems get down into the “I have nothing else that good” range. Checking one against the other is indeed an interesting thing to do. You just need a **lot** of time to do it. Bob On Nov 22, 2015, at 12:41 PM, Nick Sayer via time-nuts wrote: On Nov 22, 2015, at 7:47 AM, paul swed wrote: As mentioned a nice answer to the wwvb modulation change. I looked up the parts and it seems that they have gone into the NOS state. Though you can get some from digikey and such especially in the SOIC package. Also the VCO isn't available. It appears that the Chinese sight has the lmc6484 and LM387n at reasonable prices for small quantities. Most likely will order from there. Have not checked out the PIC chip yet. The 74H
Re: [time-nuts] KD2BD WWVB receiver/decoder in QEX
Hal wrote: It would be interesting to measure the propagation delay over a day or week, and watch the PLL error voltage over a scale of seconds or minutes. Somewhere I probably still have miles and miles of paper tape that came out of a WWVB phase comparator for many years BGE (before the GNSS era). In addition to the slow tracks, which were recorded 24/7, there were also fast tracks taken periodically. At the time, it was the only practical way to maintain NIST traceability of time and frequency measurements. The take-home points from this data (at least for those of us who are a half-continent or more distant from Ft. Collins) are (i) that the propagation delay varies quite a lot -- 10s of ppm normally, more during periods of unsettled space weather; (ii) that phenomena too numerous to count contribute to the variability, so the resultant error is a complex epicyclic function of phenomena with periods from hours to years overlaid with random noise that can be much greater than the cyclic variations; and (iii) that the amplitudes of many of the lesser cyclic errors do not fall off rapidly compared to the amplitudes of the stronger ones, so simple approximations of the epicyclic features do not allow predicting the propagation delay more closely than about tenths of a ppm (parts in e-7). Been there, done that -- for many years -- and I'm very glad we're rid of the need for it. Sometimes, progress is ... well ... progress. Best regards, Charles ___ 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] KD2BD WWVB receiver/decoder in QEX
The last NPL MSF Bulletin showing their errors was over 4 years ago: http://resource.npl.co.uk/time/bulletins/bulletin_archive.html http://www.npl.co.uk/science-technology/time-frequency/products-and-services/time/msf-radio-time-signal The error at a receiver over an interval of a couple of days is nearly completely due to propagation effects. The variations in propagation delay far exceed the error in transmitter frequency/phase control unless there are large changes in the local weather at the transmitter site. The phase of LF signals at 60 kHz is affected by the effective height of the ionosphere, which forms a 60 kHz waveguide with the Earth's surface. Unless you are very close to the transmitter, the amplitude and phase of the received signal change significantly through each 24 hour period. WWVB clocks should always measure the signal during the dark path (when the propagation path between Ft Collins CO and your location is fully dark), since that is when the signal is strongest and tends to have a more stable phase. WWVB clocks can get UTC with an uncertainty of about 100 microseconds, according to NIST: http://www.nist.gov/pml/div688/grp40/wwvb.cfm -- Bill Byrom N5BB On Sun, Nov 22, 2015, at 04:16 PM, Alan Melia wrote: > Hi Bob I have just realised that MSF may work diffently?? The Anthorn > signal is monitored by NPL at Teddington, West of London and frequency > off-sets twice a day are published in parts in 10^12 on their > web-site.involving lot of averaging I think. They do not recommend > using the signal after dark. > > You certainly could predict roughly the the skywave phase change during > the > day and the variation as the sun angle changes on the path over the year. > It > gets more difficult if there are flares or geomagnetic storms. If two > independent stations at slightly different distances collect information > it > could be corrected even more accurately. > > The same ionospheric problem occurs of course with Loran, and the now > closed > Decca system.. > > Alan > G3NYK > > > > - Original Message - > From: "Bob Camp" > To: "Nick Sayer" ; "Discussion of precise time and > frequency > measurement" > Sent: Sunday, November 22, 2015 7:34 PM > Subject: Re: [time-nuts] KD2BD WWVB receiver/decoder in QEX > > >> Hi >> >> The most basic gotcha with WWVB is that propagation can (and does) shift >> the >> carrier more than a full cycle over the course of a day. That’s at 60 KHz, >> so one >> cycle is a lot (as in 16.666 ppm). Even at one second with a not so great >> receiver >> and a poor antenna, GPS should give you ~0.01 ppm. Right up front, you >> have a bit of a problem. >> (Yes I’m mixing measurements in that comparison, but the point is still >> valid). >> >> What I keep wondering is - There is no big mystery about the WWVB >> transmitter's >> location. You likely know your own location as well. Part of demodulating >> the data >> gives you day of the year. From that you can figure out some of the basics >> of the >> propagation effects (sunrise is at X:XX sunset is at … etc). You also >> could grab stuff >> like weather data fairly easily (no idea if that actually helps). If you >> fit out the basic >> propagation impacts, WWVB could get a lot better. At the very least, you >> would know >> when to ignore the signal. >> >> So yes, you could do better today than they could back in the good old >> days in terms of >> the propagation coarse effects. >> >> Unfortunately, there also is data on 24 hour comparisons of WWVB carrier >> (same time of >> day, one day apart). If you pick your time right (noon or midnight), the >> variable propagation >> can be reduced quite a bit. Based on that data, you are doing well at 100 >> ppt over >> 24 hours. Might the new modulation help that by 10X? ..maybe. GPS over a >> 24 hour >> period should be giving you something in the 0.1 to 0.01 ppt range (same >> sort of pick a likely >> stable ionosphere time slot and compare). >> >> Does that make a WWVB device un-interesting? Not by any means. If you >> stretch out the >> time, both systems get down into the “I have nothing else that good” >> range. Checking one >> against the other is indeed an interesting thing to do. You just need a >> **lot** of time to do it. >> >> Bob >> >> >>> On Nov 22, 2015, at 12:41 PM, Nick Sayer via time-nuts >>> wrote: >>> >>> >>>> On Nov 22, 2015, at 7:47 AM, paul swed wrote: >>>> >>>>
Re: [time-nuts] KD2BD WWVB receiver/decoder in QEX
Hi It’s not to hard to detect the ionosphere changing and impacting the 60 KHz signals. If you run one of the old style strip chart systems it goes nuts as the sunrise or sunset point passes between you and the transmitter. At some point the signal may even drop by enough for the receiver to loose lock. The mechanism is the changing height of the layers as they enter or leave the sunlit region. There are indeed interesting data plots generated on the low frequency stations. Some use fancy modulation to help things out. We have yet to see how well the new modulation format on WWVB helps. One thing to consider: The distance from London to Anthorn isn’t all that far in it’s east-west component. It’s also a lot shorter distance in absolute terms than the route signals take to get to the east coast of the US from WWVB. When I go to the NPL site, http://www.npl.co.uk/science-technology/time-frequency/products-and-services/time/msf-radio-time-signal the most recent data that I see is from 2011 for MSF. http://resource.npl.co.uk/time/bulletins/bulletin_archive.html The data is in microseconds. One us would be 1.16 x 10^-11 at one day. You don’t have to dig to deep to find days with half us deltas. Comparable data on GPS from the same source shows 3 to 4 ns as about the biggest delta on a day to day basis. Based on that, you have about a 100:1 advantage with a GPS system. Bob > On Nov 22, 2015, at 5:16 PM, Alan Melia wrote: > > Hi Bob I have just realised that MSF may work diffently?? The Anthorn signal > is monitored by NPL at Teddington, West of London and frequency off-sets > twice a day are published in parts in 10^12 on their web-site.involving > lot of averaging I think. They do not recommend using the signal after dark. > > You certainly could predict roughly the the skywave phase change during the > day and the variation as the sun angle changes on the path over the year. It > gets more difficult if there are flares or geomagnetic storms. If two > independent stations at slightly different distances collect information it > could be corrected even more accurately. > > The same ionospheric problem occurs of course with Loran, and the now closed > Decca system.. > > Alan > G3NYK > > > > - Original Message - From: "Bob Camp" > To: "Nick Sayer" ; "Discussion of precise time and frequency > measurement" > Sent: Sunday, November 22, 2015 7:34 PM > Subject: Re: [time-nuts] KD2BD WWVB receiver/decoder in QEX > > >> Hi >> >> The most basic gotcha with WWVB is that propagation can (and does) shift the >> carrier more than a full cycle over the course of a day. That’s at 60 KHz, >> so one >> cycle is a lot (as in 16.666 ppm). Even at one second with a not so great >> receiver >> and a poor antenna, GPS should give you ~0.01 ppm. Right up front, you have >> a bit of a problem. >> (Yes I’m mixing measurements in that comparison, but the point is still >> valid). >> >> What I keep wondering is - There is no big mystery about the WWVB >> transmitter's >> location. You likely know your own location as well. Part of demodulating >> the data >> gives you day of the year. From that you can figure out some of the basics >> of the >> propagation effects (sunrise is at X:XX sunset is at … etc). You also could >> grab stuff >> like weather data fairly easily (no idea if that actually helps). If you fit >> out the basic >> propagation impacts, WWVB could get a lot better. At the very least, you >> would know >> when to ignore the signal. >> >> So yes, you could do better today than they could back in the good old days >> in terms of >> the propagation coarse effects. >> >> Unfortunately, there also is data on 24 hour comparisons of WWVB carrier >> (same time of >> day, one day apart). If you pick your time right (noon or midnight), the >> variable propagation >> can be reduced quite a bit. Based on that data, you are doing well at 100 >> ppt over >> 24 hours. Might the new modulation help that by 10X? ..maybe. GPS over a 24 >> hour >> period should be giving you something in the 0.1 to 0.01 ppt range (same >> sort of pick a likely >> stable ionosphere time slot and compare). >> >> Does that make a WWVB device un-interesting? Not by any means. If you >> stretch out the >> time, both systems get down into the “I have nothing else that good” range. >> Checking one >> against the other is indeed an interesting thing to do. You just need a >> *lot* of time to do it. >> >> Bob >> >> >>> On Nov 22, 2015, at 12
Re: [time-nuts] KD2BD WWVB receiver/decoder in QEX
I found all ICs except the VCXO here in the US, from only two sources; Mouser and Unicorn Electronics. A couple substitutions can be made without affecting the circuit. The 78L06 is the only change i made... substituting an LM317L adjustable regulator for the fixed 6-volt reegulator. I've attached a PDF of the IC list, sources and price. Hope this helps, Dave M Nick Sayer via time-nuts wrote: On Nov 22, 2015, at 7:47 AM, paul swed wrote: As mentioned a nice answer to the wwvb modulation change. I looked up the parts and it seems that they have gone into the NOS state. Though you can get some from digikey and such especially in the SOIC package. Also the VCO isn't available. It appears that the Chinese sight has the lmc6484 and LM387n at reasonable prices for small quantities. Most likely will order from there. Have not checked out the PIC chip yet. The 74HCXX are common and reasonable. That’s kind of a shame. I’m sure a redesign with modern SMD parts could be accomplished. The big question is how the stability of a wwvb disciplined oscillator would compare to a GPS disciplined one (all other things being equal). Well, it’s a big question for me, since I have no idea, but I imagine simply asking here will give an immediate answer. :) I’d have to guess that the PLL would behave better given a 60 kHz reference rather than a 1 Hz one. But how stable is that 60 kHz reference after going through, what, a thousand miles of ionosphere or so? ___ IC Parts List.pdf Description: Adobe PDF document ___ 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] KD2BD WWVB receiver/decoder in QEX
Hi Bob I have just realised that MSF may work diffently?? The Anthorn signal is monitored by NPL at Teddington, West of London and frequency off-sets twice a day are published in parts in 10^12 on their web-site.involving lot of averaging I think. They do not recommend using the signal after dark. You certainly could predict roughly the the skywave phase change during the day and the variation as the sun angle changes on the path over the year. It gets more difficult if there are flares or geomagnetic storms. If two independent stations at slightly different distances collect information it could be corrected even more accurately. The same ionospheric problem occurs of course with Loran, and the now closed Decca system.. Alan G3NYK - Original Message - From: "Bob Camp" To: "Nick Sayer" ; "Discussion of precise time and frequency measurement" Sent: Sunday, November 22, 2015 7:34 PM Subject: Re: [time-nuts] KD2BD WWVB receiver/decoder in QEX Hi The most basic gotcha with WWVB is that propagation can (and does) shift the carrier more than a full cycle over the course of a day. That’s at 60 KHz, so one cycle is a lot (as in 16.666 ppm). Even at one second with a not so great receiver and a poor antenna, GPS should give you ~0.01 ppm. Right up front, you have a bit of a problem. (Yes I’m mixing measurements in that comparison, but the point is still valid). What I keep wondering is - There is no big mystery about the WWVB transmitter's location. You likely know your own location as well. Part of demodulating the data gives you day of the year. From that you can figure out some of the basics of the propagation effects (sunrise is at X:XX sunset is at … etc). You also could grab stuff like weather data fairly easily (no idea if that actually helps). If you fit out the basic propagation impacts, WWVB could get a lot better. At the very least, you would know when to ignore the signal. So yes, you could do better today than they could back in the good old days in terms of the propagation coarse effects. Unfortunately, there also is data on 24 hour comparisons of WWVB carrier (same time of day, one day apart). If you pick your time right (noon or midnight), the variable propagation can be reduced quite a bit. Based on that data, you are doing well at 100 ppt over 24 hours. Might the new modulation help that by 10X? ..maybe. GPS over a 24 hour period should be giving you something in the 0.1 to 0.01 ppt range (same sort of pick a likely stable ionosphere time slot and compare). Does that make a WWVB device un-interesting? Not by any means. If you stretch out the time, both systems get down into the “I have nothing else that good” range. Checking one against the other is indeed an interesting thing to do. You just need a *lot* of time to do it. Bob On Nov 22, 2015, at 12:41 PM, Nick Sayer via time-nuts wrote: On Nov 22, 2015, at 7:47 AM, paul swed wrote: As mentioned a nice answer to the wwvb modulation change. I looked up the parts and it seems that they have gone into the NOS state. Though you can get some from digikey and such especially in the SOIC package. Also the VCO isn't available. It appears that the Chinese sight has the lmc6484 and LM387n at reasonable prices for small quantities. Most likely will order from there. Have not checked out the PIC chip yet. The 74HCXX are common and reasonable. That’s kind of a shame. I’m sure a redesign with modern SMD parts could be accomplished. The big question is how the stability of a wwvb disciplined oscillator would compare to a GPS disciplined one (all other things being equal). Well, it’s a big question for me, since I have no idea, but I imagine simply asking here will give an immediate answer. :) I’d have to guess that the PLL would behave better given a 60 kHz reference rather than a 1 Hz one. But how stable is that 60 kHz reference after going through, what, a thousand miles of ionosphere or so? ___ 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] KD2BD WWVB receiver/decoder in QEX
> Iâd have to guess that the PLL would behave better given a 60 kHz reference > rather than a 1 Hz one. But how stable is that 60 kHz reference after going > through, what, a thousand miles of ionosphere or so? One of the reasons for using 60 kHz is to avoid the ionosphere. If you measure the propagation delay, it should be stable. If you have any interest in holdover type operations, you probably will end up with a digital memory. and DAC feeding the VCO. Once you do that, the reference frequency for the PLL isn't very important. It would be interesting to measure the propagation delay over a day or week, and watch the PLL error voltage over a scale of seconds or minutes. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] KD2BD WWVB receiver/decoder in QEX
Hi The most basic gotcha with WWVB is that propagation can (and does) shift the carrier more than a full cycle over the course of a day. That’s at 60 KHz, so one cycle is a lot (as in 16.666 ppm). Even at one second with a not so great receiver and a poor antenna, GPS should give you ~0.01 ppm. Right up front, you have a bit of a problem. (Yes I’m mixing measurements in that comparison, but the point is still valid). What I keep wondering is - There is no big mystery about the WWVB transmitter's location. You likely know your own location as well. Part of demodulating the data gives you day of the year. From that you can figure out some of the basics of the propagation effects (sunrise is at X:XX sunset is at … etc). You also could grab stuff like weather data fairly easily (no idea if that actually helps). If you fit out the basic propagation impacts, WWVB could get a lot better. At the very least, you would know when to ignore the signal. So yes, you could do better today than they could back in the good old days in terms of the propagation coarse effects. Unfortunately, there also is data on 24 hour comparisons of WWVB carrier (same time of day, one day apart). If you pick your time right (noon or midnight), the variable propagation can be reduced quite a bit. Based on that data, you are doing well at 100 ppt over 24 hours. Might the new modulation help that by 10X? ..maybe. GPS over a 24 hour period should be giving you something in the 0.1 to 0.01 ppt range (same sort of pick a likely stable ionosphere time slot and compare). Does that make a WWVB device un-interesting? Not by any means. If you stretch out the time, both systems get down into the “I have nothing else that good” range. Checking one against the other is indeed an interesting thing to do. You just need a *lot* of time to do it. Bob > On Nov 22, 2015, at 12:41 PM, Nick Sayer via time-nuts > wrote: > > >> On Nov 22, 2015, at 7:47 AM, paul swed wrote: >> >> As mentioned a nice answer to the wwvb modulation change. >> I looked up the parts and it seems that they have gone into the NOS state. >> Though you can get some from digikey and such especially in the SOIC >> package. Also the VCO isn't available. >> It appears that the Chinese sight has the lmc6484 and LM387n at reasonable >> prices for small quantities. Most likely will order from there. >> Have not checked out the PIC chip yet. >> The 74HCXX are common and reasonable. > > That’s kind of a shame. I’m sure a redesign with modern SMD parts could be > accomplished. > > The big question is how the stability of a wwvb disciplined oscillator would > compare to a GPS disciplined one (all other things being equal). Well, it’s a > big question for me, since I have no idea, but I imagine simply asking here > will give an immediate answer. :) > > I’d have to guess that the PLL would behave better given a 60 kHz reference > rather than a 1 Hz one. But how stable is that 60 kHz reference after going > through, what, a thousand miles of ionosphere or so? > ___ > 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] KD2BD WWVB receiver/decoder in QEX
> On Nov 22, 2015, at 7:47 AM, paul swed wrote: > > As mentioned a nice answer to the wwvb modulation change. > I looked up the parts and it seems that they have gone into the NOS state. > Though you can get some from digikey and such especially in the SOIC > package. Also the VCO isn't available. > It appears that the Chinese sight has the lmc6484 and LM387n at reasonable > prices for small quantities. Most likely will order from there. > Have not checked out the PIC chip yet. > The 74HCXX are common and reasonable. That’s kind of a shame. I’m sure a redesign with modern SMD parts could be accomplished. The big question is how the stability of a wwvb disciplined oscillator would compare to a GPS disciplined one (all other things being equal). Well, it’s a big question for me, since I have no idea, but I imagine simply asking here will give an immediate answer. :) I’d have to guess that the PLL would behave better given a 60 kHz reference rather than a 1 Hz one. But how stable is that 60 kHz reference after going through, what, a thousand miles of ionosphere or so? ___ 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] KD2BD WWVB receiver/decoder in QEX
As mentioned a nice answer to the wwvb modulation change. I looked up the parts and it seems that they have gone into the NOS state. Though you can get some from digikey and such especially in the SOIC package. Also the VCO isn't available. It appears that the Chinese sight has the lmc6484 and LM387n at reasonable prices for small quantities. Most likely will order from there. Have not checked out the PIC chip yet. The 74HCXX are common and reasonable. Regards Paul WB8TSL On Sat, Nov 21, 2015 at 10:40 AM, Rob Sherwood. wrote: > This circuit can cope with the phase modulated time data and still provide > a frequency tracking signal for timebase adjustments? My Symmetrical WWVB > receiver is useless now. I had to go to GPSDO to validate the operation of > my two rubidiums. Rob, NC0B > > Sent from my iPad > > > On Nov 20, 2015, at 7:00 PM, "Tim Shoppa" wrote: > > > > > > > > Nov/Dec 2015 QEX has KD2BD's WWVB-based standard and decoder nicely > written > > up. > > > > His decoder has BPSK demodulation capability, BPSK output is available > but > > for the most part it detects the BPSK only to then remove BPSK prior to > > carrier phase tracking. > > > > Starts with a tuned loop antenna colocated with a 40dB preamp, then a > bunch > > of analog circuitry consisting of discrete NPN's, CMOS SPDT switches and > > op-amps, 0.025Hz low-pass filter, disciplining a 10MHz TCXO. There is > some > > digital logic (HC390's) to divide the 10MHz TCXO down and produce various > > standard frequencies, as well as a PIC to decode and display the WWVB > time > > code. Baseband WWVB signals are used to modulate a 1kHz audio tone for > > aural monitoring. > > > > Recommended reading!!! Also there is KD2BD's web description of the same > > receiver as applied to FMT's: > http://www.qsl.net/kd2bd/fmt-methodology.html > > > > Tim N3QE > > ___ > > 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. > > > > > > > > -- > > If this email is spam, report it to > > > https://support.onlymyemail.com/view/report_spam/ODExMjI6MTgyNzQ4NTU3ODpyb2JAbmMwYi5jb206ZGVsaXZlcmVk > > > ___ > 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] KD2BD WWVB receiver/decoder in QEX
This circuit can cope with the phase modulated time data and still provide a frequency tracking signal for timebase adjustments? My Symmetrical WWVB receiver is useless now. I had to go to GPSDO to validate the operation of my two rubidiums. Rob, NC0B Sent from my iPad > On Nov 20, 2015, at 7:00 PM, "Tim Shoppa" wrote: > > > > Nov/Dec 2015 QEX has KD2BD's WWVB-based standard and decoder nicely written > up. > > His decoder has BPSK demodulation capability, BPSK output is available but > for the most part it detects the BPSK only to then remove BPSK prior to > carrier phase tracking. > > Starts with a tuned loop antenna colocated with a 40dB preamp, then a bunch > of analog circuitry consisting of discrete NPN's, CMOS SPDT switches and > op-amps, 0.025Hz low-pass filter, disciplining a 10MHz TCXO. There is some > digital logic (HC390's) to divide the 10MHz TCXO down and produce various > standard frequencies, as well as a PIC to decode and display the WWVB time > code. Baseband WWVB signals are used to modulate a 1kHz audio tone for > aural monitoring. > > Recommended reading!!! Also there is KD2BD's web description of the same > receiver as applied to FMT's: http://www.qsl.net/kd2bd/fmt-methodology.html > > Tim N3QE > ___ > 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. > > > > -- > If this email is spam, report it to > https://support.onlymyemail.com/view/report_spam/ODExMjI6MTgyNzQ4NTU3ODpyb2JAbmMwYi5jb206ZGVsaXZlcmVk > ___ 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] KD2BD WWVB receiver/decoder in QEX
I don't subscribe to QEX but it seems that ARRL has kindly provided an easily accessible online copy of the noted article here: http://www.arrl.org/files/file/QEX_Next_Issue/2015/Nov-Dec_2015/Magliacane.pdf Downloaded and made ready for reading later today, thank you for posting the "head's up" on KD2BD's article. cheers, Graham ve3gtc On 2015-11-20 23:29, Tim Shoppa wrote: Nov/Dec 2015 QEX has KD2BD's WWVB-based standard and decoder nicely written up. His decoder has BPSK demodulation capability, BPSK output is available but for the most part it detects the BPSK only to then remove BPSK prior to carrier phase tracking. Starts with a tuned loop antenna colocated with a 40dB preamp, then a bunch of analog circuitry consisting of discrete NPN's, CMOS SPDT switches and op-amps, 0.025Hz low-pass filter, disciplining a 10MHz TCXO. There is some digital logic (HC390's) to divide the 10MHz TCXO down and produce various standard frequencies, as well as a PIC to decode and display the WWVB time code. Baseband WWVB signals are used to modulate a 1kHz audio tone for aural monitoring. Recommended reading!!! Also there is KD2BD's web description of the same receiver as applied to FMT's: http://www.qsl.net/kd2bd/fmt-methodology.html Tim N3QE ___ 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] KD2BD WWVB receiver/decoder in QEX
Tim Its a good article and Reginald and I have been discussing offline. If you like lots of opamps its very good. Its pretty much all discreet easy to wire parts. But a lot of them. We have looked at the 10 Mhz VCO and even calling Bomar and its not available so will guess like many projects its what was on hand. Same with the very wide range of opamps. That said its a very up to date wwvb receiver. Regards Paul WB8TSL On Fri, Nov 20, 2015 at 6:29 PM, Tim Shoppa wrote: > Nov/Dec 2015 QEX has KD2BD's WWVB-based standard and decoder nicely written > up. > > His decoder has BPSK demodulation capability, BPSK output is available but > for the most part it detects the BPSK only to then remove BPSK prior to > carrier phase tracking. > > Starts with a tuned loop antenna colocated with a 40dB preamp, then a bunch > of analog circuitry consisting of discrete NPN's, CMOS SPDT switches and > op-amps, 0.025Hz low-pass filter, disciplining a 10MHz TCXO. There is some > digital logic (HC390's) to divide the 10MHz TCXO down and produce various > standard frequencies, as well as a PIC to decode and display the WWVB time > code. Baseband WWVB signals are used to modulate a 1kHz audio tone for > aural monitoring. > > Recommended reading!!! Also there is KD2BD's web description of the same > receiver as applied to FMT's: > http://www.qsl.net/kd2bd/fmt-methodology.html > > Tim N3QE > ___ > 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] KD2BD WWVB receiver/decoder in QEX
Nov/Dec 2015 QEX has KD2BD's WWVB-based standard and decoder nicely written up. His decoder has BPSK demodulation capability, BPSK output is available but for the most part it detects the BPSK only to then remove BPSK prior to carrier phase tracking. Starts with a tuned loop antenna colocated with a 40dB preamp, then a bunch of analog circuitry consisting of discrete NPN's, CMOS SPDT switches and op-amps, 0.025Hz low-pass filter, disciplining a 10MHz TCXO. There is some digital logic (HC390's) to divide the 10MHz TCXO down and produce various standard frequencies, as well as a PIC to decode and display the WWVB time code. Baseband WWVB signals are used to modulate a 1kHz audio tone for aural monitoring. Recommended reading!!! Also there is KD2BD's web description of the same receiver as applied to FMT's: http://www.qsl.net/kd2bd/fmt-methodology.html Tim N3QE ___ 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.
