[time-nuts] WWVB PM Time Questions
I'm not sure what I will use for the VCTCXO. I have a few different ideas to play around with. Testing when I have time over the next couple of weeks I may find a suitable solution. Ray, AB7HE Original Message Subject: Re: [time-nuts] WWVB PM Time Questions From: paul swed Date: Wed, July 22, 2020 7:09 pm To: Discussion of precise time and frequency measurement Looked at the KD2BD schematic and it is a 10 MHz VCTCXO. That seems reasonable perhaps to find. Regards Paul On Wed, Jul 22, 2020 at 6:44 PM paul swed wrote: > I was actually thinking about this quite a bit and perhaps I went the > wrong way. > That is a cheap vcxo class device. His unit was not an oven as I recall. > Just maybe a bit too good was actually bad. > Hard to say and no time to play right now. > Regards > Paul > WB8TSL > > On Wed, Jul 22, 2020 at 6:06 PM Bob kb8tq wrote: > >> Hi >> >> >> >> > On Jul 22, 2020, at 3:51 PM, paul swed wrote: >> > >> > Ray watch out for my comment on the KD2BD solution. That oscillator >> isn't >> > available and I have not been able to map something else into it. Tried >> > several good grade Oven oscillators. Just be aware of that issue. >> > Would need to do more tinkering and simply don't have that time right >> now. >> > Also it would be great if the oscillator was something that could be >> > obtained at a reasonable cost. I do not believe at all it has to be a >> > OCXO as the older true time and spectracoms were not and they locked >> solid. >> > So its a case of getting the control voltages right. >> >> You can buy a surprisingly good little OCXO (for the price) on eBay these >> days in the $3 to $6 range. Find one at 12.6 MHz and it will divide >> nicely to >> 60 KHz. 19.2 MHz looks like a better candidate … Either way I have not >> (yet) >> seen a 60 KHz multiple show up in the cheap category. >> >> Bob >> >> >> > Regards >> > Paul. >> > >> > On Wed, Jul 22, 2020 at 3:29 PM wrote: >> > >> >> Thanks to all for the suggestions. I dug a ferrite rod AM radio antenna >> >> out of the box this morning. I have a box of 10 left over from the late >> >> 80s. It measures 0.950 mH so I will add some turns to get it to 1.5 mH >> >> which will be easier to resonate at 60 kHz. Then I need to build up the >> >> RF amp and run the output through a 60 kHz crystal filter. I have to >> >> order the crystals since I don't have any on hand. It will take a >> couple >> >> of weeks to get the front end working. >> >> >> >> I am in Phoenix so the WWVB signal is of decent quality here even >> during >> >> the daytime. My 25 year old cheap Casio watch will sync up within 2-3 >> >> minutes any time of day or night. It normally syncs at 2 am but I have >> >> done tests to confirm daytime sync works reliably. >> >> >> >> Mark, I know virtually nothing about SDR other than it works. I bought >> a >> >> RTL-SDR.Com module a couple of years ago and played with it a little >> >> bit. But it quit working and I haven't thought about SDR since then. My >> >> Icom 7300 is a SDR and it works very well. I think to attempt to design >> >> a SDR would be well over my head. I anticipate this project taking 2-3 >> >> months. If I get it working I will be glad to share everything with the >> >> group. >> >> >> >> Lester and Paul, I will test with the Costas loop as it may be the >> >> easiest way to go. To test the Costas loop I am basically going to >> >> duplicate the KD2BD design. I was reluctant about it in the beginning >> >> but more reading seems to indicate it will be fine. My AWG allows me to >> >> set the phase from 0 to 360 degrees independently on each channel so I >> >> can use that for initial testing. That testing can be done prior to >> >> getting the front end working. >> >> >> >> Richard, is your software posted somewhere? I assume it allows you to >> >> specify the time and date you want it to send. That would come in handy >> >> for writing the code to extract the timer/date data. I have seen >> >> examples of the Arduino transmitting the old AM signal but don't recall >> >> seeing one that sends the BPSK stream. >> >> >> >> I have a GPS time receiver with a 1.2 inch LED display that I built a >> >> couple of years ago. I have it setup so the UART outputs the gprmc NEMA >> >> string in case I want to look at it. I have a couple of spare GPS >> >> modules lying around and several Arduino Uno modules. I have no problem >> >> picking up the GPS satellites using only the patch antenna that is >> built >> >> into the modules. >> >> >> >> Ray, >> >> AB7HE >> >> >> >> >> >> ___ >> >> time-nuts mailing list -- time-nuts@lists.febo.com >> >> To unsubscribe, go to >> >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> >> and follow the instructions there. >> >> >> > ___ >> > time-nuts mailing list -- time-nuts@lists.febo.com >> > To unsubscribe, go to >>
Re: [time-nuts] WWVB PM Time Questions
Looked at the KD2BD schematic and it is a 10 MHz VCTCXO. That seems reasonable perhaps to find. Regards Paul On Wed, Jul 22, 2020 at 6:44 PM paul swed wrote: > I was actually thinking about this quite a bit and perhaps I went the > wrong way. > That is a cheap vcxo class device. His unit was not an oven as I recall. > Just maybe a bit too good was actually bad. > Hard to say and no time to play right now. > Regards > Paul > WB8TSL > > On Wed, Jul 22, 2020 at 6:06 PM Bob kb8tq wrote: > >> Hi >> >> >> >> > On Jul 22, 2020, at 3:51 PM, paul swed wrote: >> > >> > Ray watch out for my comment on the KD2BD solution. That oscillator >> isn't >> > available and I have not been able to map something else into it. Tried >> > several good grade Oven oscillators. Just be aware of that issue. >> > Would need to do more tinkering and simply don't have that time right >> now. >> > Also it would be great if the oscillator was something that could be >> > obtained at a reasonable cost. I do not believe at all it has to be a >> > OCXO as the older true time and spectracoms were not and they locked >> solid. >> > So its a case of getting the control voltages right. >> >> You can buy a surprisingly good little OCXO (for the price) on eBay these >> days in the $3 to $6 range. Find one at 12.6 MHz and it will divide >> nicely to >> 60 KHz. 19.2 MHz looks like a better candidate … Either way I have not >> (yet) >> seen a 60 KHz multiple show up in the cheap category. >> >> Bob >> >> >> > Regards >> > Paul. >> > >> > On Wed, Jul 22, 2020 at 3:29 PM wrote: >> > >> >> Thanks to all for the suggestions. I dug a ferrite rod AM radio antenna >> >> out of the box this morning. I have a box of 10 left over from the late >> >> 80s. It measures 0.950 mH so I will add some turns to get it to 1.5 mH >> >> which will be easier to resonate at 60 kHz. Then I need to build up the >> >> RF amp and run the output through a 60 kHz crystal filter. I have to >> >> order the crystals since I don't have any on hand. It will take a >> couple >> >> of weeks to get the front end working. >> >> >> >> I am in Phoenix so the WWVB signal is of decent quality here even >> during >> >> the daytime. My 25 year old cheap Casio watch will sync up within 2-3 >> >> minutes any time of day or night. It normally syncs at 2 am but I have >> >> done tests to confirm daytime sync works reliably. >> >> >> >> Mark, I know virtually nothing about SDR other than it works. I bought >> a >> >> RTL-SDR.Com module a couple of years ago and played with it a little >> >> bit. But it quit working and I haven't thought about SDR since then. My >> >> Icom 7300 is a SDR and it works very well. I think to attempt to design >> >> a SDR would be well over my head. I anticipate this project taking 2-3 >> >> months. If I get it working I will be glad to share everything with the >> >> group. >> >> >> >> Lester and Paul, I will test with the Costas loop as it may be the >> >> easiest way to go. To test the Costas loop I am basically going to >> >> duplicate the KD2BD design. I was reluctant about it in the beginning >> >> but more reading seems to indicate it will be fine. My AWG allows me to >> >> set the phase from 0 to 360 degrees independently on each channel so I >> >> can use that for initial testing. That testing can be done prior to >> >> getting the front end working. >> >> >> >> Richard, is your software posted somewhere? I assume it allows you to >> >> specify the time and date you want it to send. That would come in handy >> >> for writing the code to extract the timer/date data. I have seen >> >> examples of the Arduino transmitting the old AM signal but don't recall >> >> seeing one that sends the BPSK stream. >> >> >> >> I have a GPS time receiver with a 1.2 inch LED display that I built a >> >> couple of years ago. I have it setup so the UART outputs the gprmc NEMA >> >> string in case I want to look at it. I have a couple of spare GPS >> >> modules lying around and several Arduino Uno modules. I have no problem >> >> picking up the GPS satellites using only the patch antenna that is >> built >> >> into the modules. >> >> >> >> Ray, >> >> AB7HE >> >> >> >> >> >> ___ >> >> time-nuts mailing list -- time-nuts@lists.febo.com >> >> To unsubscribe, go to >> >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> >> and follow the instructions there. >> >> >> > ___ >> > time-nuts mailing list -- time-nuts@lists.febo.com >> > To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> > and follow the instructions there. >> >> >> ___ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. >> > ___ time-nuts mailing list --
Re: [time-nuts] WWVB PM Time Questions
I was actually thinking about this quite a bit and perhaps I went the wrong way. That is a cheap vcxo class device. His unit was not an oven as I recall. Just maybe a bit too good was actually bad. Hard to say and no time to play right now. Regards Paul WB8TSL On Wed, Jul 22, 2020 at 6:06 PM Bob kb8tq wrote: > Hi > > > > > On Jul 22, 2020, at 3:51 PM, paul swed wrote: > > > > Ray watch out for my comment on the KD2BD solution. That oscillator isn't > > available and I have not been able to map something else into it. Tried > > several good grade Oven oscillators. Just be aware of that issue. > > Would need to do more tinkering and simply don't have that time right > now. > > Also it would be great if the oscillator was something that could be > > obtained at a reasonable cost. I do not believe at all it has to be a > > OCXO as the older true time and spectracoms were not and they locked > solid. > > So its a case of getting the control voltages right. > > You can buy a surprisingly good little OCXO (for the price) on eBay these > days in the $3 to $6 range. Find one at 12.6 MHz and it will divide > nicely to > 60 KHz. 19.2 MHz looks like a better candidate … Either way I have not > (yet) > seen a 60 KHz multiple show up in the cheap category. > > Bob > > > > Regards > > Paul. > > > > On Wed, Jul 22, 2020 at 3:29 PM wrote: > > > >> Thanks to all for the suggestions. I dug a ferrite rod AM radio antenna > >> out of the box this morning. I have a box of 10 left over from the late > >> 80s. It measures 0.950 mH so I will add some turns to get it to 1.5 mH > >> which will be easier to resonate at 60 kHz. Then I need to build up the > >> RF amp and run the output through a 60 kHz crystal filter. I have to > >> order the crystals since I don't have any on hand. It will take a couple > >> of weeks to get the front end working. > >> > >> I am in Phoenix so the WWVB signal is of decent quality here even during > >> the daytime. My 25 year old cheap Casio watch will sync up within 2-3 > >> minutes any time of day or night. It normally syncs at 2 am but I have > >> done tests to confirm daytime sync works reliably. > >> > >> Mark, I know virtually nothing about SDR other than it works. I bought a > >> RTL-SDR.Com module a couple of years ago and played with it a little > >> bit. But it quit working and I haven't thought about SDR since then. My > >> Icom 7300 is a SDR and it works very well. I think to attempt to design > >> a SDR would be well over my head. I anticipate this project taking 2-3 > >> months. If I get it working I will be glad to share everything with the > >> group. > >> > >> Lester and Paul, I will test with the Costas loop as it may be the > >> easiest way to go. To test the Costas loop I am basically going to > >> duplicate the KD2BD design. I was reluctant about it in the beginning > >> but more reading seems to indicate it will be fine. My AWG allows me to > >> set the phase from 0 to 360 degrees independently on each channel so I > >> can use that for initial testing. That testing can be done prior to > >> getting the front end working. > >> > >> Richard, is your software posted somewhere? I assume it allows you to > >> specify the time and date you want it to send. That would come in handy > >> for writing the code to extract the timer/date data. I have seen > >> examples of the Arduino transmitting the old AM signal but don't recall > >> seeing one that sends the BPSK stream. > >> > >> I have a GPS time receiver with a 1.2 inch LED display that I built a > >> couple of years ago. I have it setup so the UART outputs the gprmc NEMA > >> string in case I want to look at it. I have a couple of spare GPS > >> modules lying around and several Arduino Uno modules. I have no problem > >> picking up the GPS satellites using only the patch antenna that is built > >> into the modules. > >> > >> Ray, > >> AB7HE > >> > >> > >> ___ > >> time-nuts mailing list -- time-nuts@lists.febo.com > >> To unsubscribe, go to > >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > >> and follow the instructions there. > >> > > ___ > > time-nuts mailing list -- time-nuts@lists.febo.com > > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > > and follow the instructions there. > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] WWVB PM Time Questions
Hi > On Jul 22, 2020, at 3:51 PM, paul swed wrote: > > Ray watch out for my comment on the KD2BD solution. That oscillator isn't > available and I have not been able to map something else into it. Tried > several good grade Oven oscillators. Just be aware of that issue. > Would need to do more tinkering and simply don't have that time right now. > Also it would be great if the oscillator was something that could be > obtained at a reasonable cost. I do not believe at all it has to be a > OCXO as the older true time and spectracoms were not and they locked solid. > So its a case of getting the control voltages right. You can buy a surprisingly good little OCXO (for the price) on eBay these days in the $3 to $6 range. Find one at 12.6 MHz and it will divide nicely to 60 KHz. 19.2 MHz looks like a better candidate … Either way I have not (yet) seen a 60 KHz multiple show up in the cheap category. Bob > Regards > Paul. > > On Wed, Jul 22, 2020 at 3:29 PM wrote: > >> Thanks to all for the suggestions. I dug a ferrite rod AM radio antenna >> out of the box this morning. I have a box of 10 left over from the late >> 80s. It measures 0.950 mH so I will add some turns to get it to 1.5 mH >> which will be easier to resonate at 60 kHz. Then I need to build up the >> RF amp and run the output through a 60 kHz crystal filter. I have to >> order the crystals since I don't have any on hand. It will take a couple >> of weeks to get the front end working. >> >> I am in Phoenix so the WWVB signal is of decent quality here even during >> the daytime. My 25 year old cheap Casio watch will sync up within 2-3 >> minutes any time of day or night. It normally syncs at 2 am but I have >> done tests to confirm daytime sync works reliably. >> >> Mark, I know virtually nothing about SDR other than it works. I bought a >> RTL-SDR.Com module a couple of years ago and played with it a little >> bit. But it quit working and I haven't thought about SDR since then. My >> Icom 7300 is a SDR and it works very well. I think to attempt to design >> a SDR would be well over my head. I anticipate this project taking 2-3 >> months. If I get it working I will be glad to share everything with the >> group. >> >> Lester and Paul, I will test with the Costas loop as it may be the >> easiest way to go. To test the Costas loop I am basically going to >> duplicate the KD2BD design. I was reluctant about it in the beginning >> but more reading seems to indicate it will be fine. My AWG allows me to >> set the phase from 0 to 360 degrees independently on each channel so I >> can use that for initial testing. That testing can be done prior to >> getting the front end working. >> >> Richard, is your software posted somewhere? I assume it allows you to >> specify the time and date you want it to send. That would come in handy >> for writing the code to extract the timer/date data. I have seen >> examples of the Arduino transmitting the old AM signal but don't recall >> seeing one that sends the BPSK stream. >> >> I have a GPS time receiver with a 1.2 inch LED display that I built a >> couple of years ago. I have it setup so the UART outputs the gprmc NEMA >> string in case I want to look at it. I have a couple of spare GPS >> modules lying around and several Arduino Uno modules. I have no problem >> picking up the GPS satellites using only the patch antenna that is built >> into the modules. >> >> Ray, >> AB7HE >> >> >> ___ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. >> > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] For those following ES100 WWVB receiver modules
The generic WWVB receivers in radio-controlled clocks are essentially TRF receivers using a 60kHz crystal as the tuned element. David N1HAC On 7/22/20 2:26 PM, Hal Murray wrote: tsho...@gmail.com said: I myself did some experimenting with a tuned loop antenna through a 60 kHz crystal bandpass hooked to a ... What is the bandwidth of the WWVB signal? What is the bandwidth of a crystal filter? (or probably, what are my choices, and what do I get if I use a low cost crystal?) ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] WWVB PM Time Questions
Ray watch out for my comment on the KD2BD solution. That oscillator isn't available and I have not been able to map something else into it. Tried several good grade Oven oscillators. Just be aware of that issue. Would need to do more tinkering and simply don't have that time right now. Also it would be great if the oscillator was something that could be obtained at a reasonable cost. I do not believe at all it has to be a OCXO as the older true time and spectracoms were not and they locked solid. So its a case of getting the control voltages right. Regards Paul. On Wed, Jul 22, 2020 at 3:29 PM wrote: > Thanks to all for the suggestions. I dug a ferrite rod AM radio antenna > out of the box this morning. I have a box of 10 left over from the late > 80s. It measures 0.950 mH so I will add some turns to get it to 1.5 mH > which will be easier to resonate at 60 kHz. Then I need to build up the > RF amp and run the output through a 60 kHz crystal filter. I have to > order the crystals since I don't have any on hand. It will take a couple > of weeks to get the front end working. > > I am in Phoenix so the WWVB signal is of decent quality here even during > the daytime. My 25 year old cheap Casio watch will sync up within 2-3 > minutes any time of day or night. It normally syncs at 2 am but I have > done tests to confirm daytime sync works reliably. > > Mark, I know virtually nothing about SDR other than it works. I bought a > RTL-SDR.Com module a couple of years ago and played with it a little > bit. But it quit working and I haven't thought about SDR since then. My > Icom 7300 is a SDR and it works very well. I think to attempt to design > a SDR would be well over my head. I anticipate this project taking 2-3 > months. If I get it working I will be glad to share everything with the > group. > > Lester and Paul, I will test with the Costas loop as it may be the > easiest way to go. To test the Costas loop I am basically going to > duplicate the KD2BD design. I was reluctant about it in the beginning > but more reading seems to indicate it will be fine. My AWG allows me to > set the phase from 0 to 360 degrees independently on each channel so I > can use that for initial testing. That testing can be done prior to > getting the front end working. > > Richard, is your software posted somewhere? I assume it allows you to > specify the time and date you want it to send. That would come in handy > for writing the code to extract the timer/date data. I have seen > examples of the Arduino transmitting the old AM signal but don't recall > seeing one that sends the BPSK stream. > > I have a GPS time receiver with a 1.2 inch LED display that I built a > couple of years ago. I have it setup so the UART outputs the gprmc NEMA > string in case I want to look at it. I have a couple of spare GPS > modules lying around and several Arduino Uno modules. I have no problem > picking up the GPS satellites using only the patch antenna that is built > into the modules. > > Ray, > AB7HE > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
[time-nuts] WWVB PM Time Questions
Thanks to all for the suggestions. I dug a ferrite rod AM radio antenna out of the box this morning. I have a box of 10 left over from the late 80s. It measures 0.950 mH so I will add some turns to get it to 1.5 mH which will be easier to resonate at 60 kHz. Then I need to build up the RF amp and run the output through a 60 kHz crystal filter. I have to order the crystals since I don't have any on hand. It will take a couple of weeks to get the front end working. I am in Phoenix so the WWVB signal is of decent quality here even during the daytime. My 25 year old cheap Casio watch will sync up within 2-3 minutes any time of day or night. It normally syncs at 2 am but I have done tests to confirm daytime sync works reliably. Mark, I know virtually nothing about SDR other than it works. I bought a RTL-SDR.Com module a couple of years ago and played with it a little bit. But it quit working and I haven't thought about SDR since then. My Icom 7300 is a SDR and it works very well. I think to attempt to design a SDR would be well over my head. I anticipate this project taking 2-3 months. If I get it working I will be glad to share everything with the group. Lester and Paul, I will test with the Costas loop as it may be the easiest way to go. To test the Costas loop I am basically going to duplicate the KD2BD design. I was reluctant about it in the beginning but more reading seems to indicate it will be fine. My AWG allows me to set the phase from 0 to 360 degrees independently on each channel so I can use that for initial testing. That testing can be done prior to getting the front end working. Richard, is your software posted somewhere? I assume it allows you to specify the time and date you want it to send. That would come in handy for writing the code to extract the timer/date data. I have seen examples of the Arduino transmitting the old AM signal but don't recall seeing one that sends the BPSK stream. I have a GPS time receiver with a 1.2 inch LED display that I built a couple of years ago. I have it setup so the UART outputs the gprmc NEMA string in case I want to look at it. I have a couple of spare GPS modules lying around and several Arduino Uno modules. I have no problem picking up the GPS satellites using only the patch antenna that is built into the modules. Ray, AB7HE ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] For those following ES100 WWVB receiver modules
Is there a gnu radio receiver? Should be able to handle this speed. Don On 2020-07-22 11:41, Tim Shoppa wrote: The ES100 module sold by universal-solder.ca which Tom introduced us to a couple years ago, is now End-Of-Life. "A new module is currently in development". https://www.universal-solder.ca/product/everset-es100-cob-wwvb-60khz-bpsk-receiver-kit-with-2-antennas/ I myself did some experimenting with a tuned loop antenna through a 60 kHz crystal bandpass hooked to a 192k sample rate USB audio card. I can post process data to pull out phase shifts and time code but am nowhere near doing this in real-time. Tim N3QE ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. -- Dr. Don Latham AJ7LL PO Box 404, Frenchtown, MT, 59834 VOX: 406-626-4304 ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] WWVB PM Time Questions
Software Costas, see MatLab: https://www.mathworks.com/matlabcentral/fileexchange/16744-demodulating-a-bp sk-using-costas-loop?s_tid=FX_rc2_behav Lester B Veenstra K1YCM MØYCM W8YCM 6Y6Y les...@veenstras.com 452 Stable Ln (HC84 RFD USPS Mail) Keyser WV 26726 GPS: 39.336826 N 78.982287 W (Google) GPS: 39.33682 N 78.9823741 W (GPSDO) Telephones: Home: +1-304-289-6057 US cell +1-304-790-9192 Jamaica cell: +1-876-456-8898 -Original Message- From: time-nuts [mailto:time-nuts-boun...@lists.febo.com] On Behalf Of paul swed Sent: Wednesday, July 22, 2020 1:26 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] WWVB PM Time Questions The KD2BD receiver is a costas loop. So look at that and you have the answer. It does not decode the BPSK data though. Thats quite a project all by itself. Regards Paul On Wed, Jul 22, 2020 at 10:42 AM Rodger via time-nuts < time-nuts@lists.febo.com> wrote: > Hey Ray, > > Paul and I have a nice piece of code that generates the WWVB BPSK bit > stream > using an Arduino and a ublox GPS module. (total cost under $30) You could > use this as a WWVB emulator while you're working on your code. Sorry, I > can't really help with your question about demodulating the WWVB BPSK but > the Costas loop sounds like the way to go. It has also been suggested that > a WWVB SDR wouldn't be too difficult to build and would open up lots of > possibilities. Unfortunately, I don't have a clue where to begin with > that. > Maybe somebody with some SDR experience can chime in. > > Re your comment about $30 BPSK clocks. The only clock I'm aware of that > uses the BPSK is the Lacrosse Ultratomic. Are you aware of any others? > > Thanks, > > Rodger > > -Original Message- > From: time-nuts On Behalf Of > rcb...@atcelectronics.com > Sent: Tuesday, July 21, 2020 11:52 PM > To: Discussion of precise time and frequency measurement > > Subject: Re: [time-nuts] WWVB PM Time Questions > > Paul, thanks for the suggestions. The top of the minute is a good idea. > Since the first second is part of the sync pattern it will always be 0 and > the phase would be 0. A differential opamp with one input from WWVB and the > other from the local source fed to the STM32 would tell if the signals were > in phase. A single gate inverter controlled by the STM32 could be used to > invert the local source if necessary. > > I have worked with the Bluepill for the last year on a few small projects. > The most complex one (which isn't really complex) was to control two > stepper > motors. I really like the boards and you can't beat the prices. I don't use > the bootloader so I have no experience with it. > > Dana, I looked at the Costas loop and had sort of ruled it out. I may take > another look at it as I get further into the project. I will probably use a > 15.360 MHz oscillator and divide by 256 to get the 60 kHz local source. > Once > I get the front end working I will be able to start some "real" testing. > > Suggestions from others are welcome. > > Ray, > AB7HE > > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] For those following ES100 WWVB receiver modules
tsho...@gmail.com said: > I myself did some experimenting with a tuned loop antenna through a 60 kHz > crystal bandpass hooked to a ... What is the bandwidth of the WWVB signal? What is the bandwidth of a crystal filter? (or probably, what are my choices, and what do I get if I use a low cost crystal?) -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
[time-nuts] For those following ES100 WWVB receiver modules
The ES100 module sold by universal-solder.ca which Tom introduced us to a couple years ago, is now End-Of-Life. "A new module is currently in development". https://www.universal-solder.ca/product/everset-es100-cob-wwvb-60khz-bpsk-receiver-kit-with-2-antennas/ I myself did some experimenting with a tuned loop antenna through a 60 kHz crystal bandpass hooked to a 192k sample rate USB audio card. I can post process data to pull out phase shifts and time code but am nowhere near doing this in real-time. Tim N3QE ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] WWVB PM Time Questions
The KD2BD receiver is a costas loop. So look at that and you have the answer. It does not decode the BPSK data though. Thats quite a project all by itself. Regards Paul On Wed, Jul 22, 2020 at 10:42 AM Rodger via time-nuts < time-nuts@lists.febo.com> wrote: > Hey Ray, > > Paul and I have a nice piece of code that generates the WWVB BPSK bit > stream > using an Arduino and a ublox GPS module. (total cost under $30) You could > use this as a WWVB emulator while you're working on your code. Sorry, I > can't really help with your question about demodulating the WWVB BPSK but > the Costas loop sounds like the way to go. It has also been suggested that > a WWVB SDR wouldn't be too difficult to build and would open up lots of > possibilities. Unfortunately, I don't have a clue where to begin with > that. > Maybe somebody with some SDR experience can chime in. > > Re your comment about $30 BPSK clocks. The only clock I'm aware of that > uses the BPSK is the Lacrosse Ultratomic. Are you aware of any others? > > Thanks, > > Rodger > > -Original Message- > From: time-nuts On Behalf Of > rcb...@atcelectronics.com > Sent: Tuesday, July 21, 2020 11:52 PM > To: Discussion of precise time and frequency measurement > > Subject: Re: [time-nuts] WWVB PM Time Questions > > Paul, thanks for the suggestions. The top of the minute is a good idea. > Since the first second is part of the sync pattern it will always be 0 and > the phase would be 0. A differential opamp with one input from WWVB and the > other from the local source fed to the STM32 would tell if the signals were > in phase. A single gate inverter controlled by the STM32 could be used to > invert the local source if necessary. > > I have worked with the Bluepill for the last year on a few small projects. > The most complex one (which isn't really complex) was to control two > stepper > motors. I really like the boards and you can't beat the prices. I don't use > the bootloader so I have no experience with it. > > Dana, I looked at the Costas loop and had sort of ruled it out. I may take > another look at it as I get further into the project. I will probably use a > 15.360 MHz oscillator and divide by 256 to get the 60 kHz local source. > Once > I get the front end working I will be able to start some "real" testing. > > Suggestions from others are welcome. > > Ray, > AB7HE > > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] WWVB PM Time Questions
Hi Ray, A similar project has been on my to-do list for a couple of years now (so don't hold your breath!). It should be possible to do this using the built-in ADC for a really nice, minimalist demonstration of SDR principles. The STM32L4 series which I often use has a pretty decent ADC: fast (5 MSPS), with about 11 good bits in differential mode, and "proper" hardware downsampling (called the DFSDM in the manual). If the noise is white it should be easy to get > 16 good bits into the demodulator. My plan was to clock the MCU from a cheap OCXO and make it part of the carrier tracking loop, for a simple WWVB disciplined oscillator. I also have some questions about the NIST document, but in general, I think you need to assume that your receiver is already locked, in which case you know when to expect the transitions. Getting to this point (acquisition) is another story, but there are all sorts of correlation-based tricks that you can use, similar to GPS code acquisition. As others have noted, carrier phase lock can be aided by squaring. My problem is that the SDR stuff is all pretty straightforward for me, but the analog electronics leading up to the ADC are black magic. I have a preamp circuit modeled on John Magliacane's design (http://www.arrl.org/files/file/QEX_Next_Issue/2015/Nov-Dec_2015/Magliacane.pdf), fed from a ~ 60-turn tuned loop made from old ribbon cable, but I am having problems getting anything "reasonable" looking on the scope. I don't know if the problem is my suburban location or if you really can't see the signal until you get the bandwidth << 1 kHz. (I am using RC-tuned op-amp stages so the -3 dB response is necessarily a few kHz.) Eventually I would like a small loopstick design with a crystal filter like the off-the-shelf clocks use, but I haven't a clue how to get there. Maybe this project would benefit from a collaboration :) Regards, Mark On 21-Jul-20 4:37 PM, rcb...@atcelectronics.com wrote: > I want to decode the WWVB time information using the BPSK information > that is broadcast. I will use a STM32 to do the actual decoding of the > bit stream. This is just an exercise in "can I do it?" as I know I can > buy clocks for $30 that use the BPSK method. At one time you could buy > an IC that output the data stream but I believe there is nothing > currently available to do that. > > I read the document "Enhanced WWVB Broadcast Format" by John Lowe from > NIST. One thing that is confusing to me is this paragraph: "Although the > phase representing the information in each symbol is shown to be > available before the amplitude in it transitions from VH to VL, it is > recommended that receivers extract it only from the high amplitude > portion of the symbol. This is not only because of the higher power > there, allowing for more robust phase demodulation, but also because the > low amplitude portion may be used in the future for additional (higher > rate) phase modulation." > > How would you detect the phase had changed if you don't detect it when > it changes at 100 msec after the carrier level drops? After the signal > reverses phase wouldn't any reference you are using then be in lock with > the current phase of the signal after it has changed? > > Or would you use a locally generated 60 kHz ultra stable signal as the > phase reference? If so, how would you keep your local source locked to > the 0 degree phase signal of WWVB and have it ignore the 180 degree > phase shift? > > I have done a lot of searching and reading from various sources. But I > haven't really found a good explanation of the hardware that would be > used to detect the phase changes. Is there a block diagram somewhere > that would illustrate the steps needed to detect the change during the > high power portion of the WWVB signal? > > I am going to put together a 60 kHz amplifier using a couple of > FET/transistors and a couple of high speed opamps. Then I can observe > the signal on my scope. Using the output of the amp I can then try to > figure out the best way to detect the phase changes. I can use my AWG to > supply the local 60 kHz signal source. > > I have found two articles that give me some ideas. One is the Nov/Dec > QEX article by John, KD2BD and the other is an article titled WWV > de-PSK-r by Paul, WB8TSL. Paul is a member of this list. > > Can someone make other suggestions that will get me pointed in the > correct direction? > > Thanks, > Ray, AB7HE > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] WWVB PM Time Questions
On 7/22/2020 7:35 AM, Rodger via time-nuts wrote: Hey Ray, Paul and I have a nice piece of code that generates the WWVB BPSK bit stream using an Arduino and a ublox GPS module. (total cost under $30) You could use this as a WWVB emulator while you're working on your code. Sorry, I can't really help with your question about demodulating the WWVB BPSK but the Costas loop sounds like the way to go. Rodger A long time ago, I built a demodulator for some weather satellite that used BPSK that used a Costas loop driving a VCXO. I had never built a Costas loop before, but I have to say that it was quite straightforward and it totally worked as advertised. The loop requires an analog multiplier, and I didn't have much trouble sourcing it. Fast forward to today, and the same small number of multipliers are still available, they just cost a lot. For 60 kHz, of course, you will want to divide down a VCXO that is at a reasonable frequency for such. Rick N6RK ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] WWVB PM Time Questions
Ray: If you will pardon the obvious, once digitized, in software, simply square to remove the phase, or better still, a Costas Loop to sync demod. Lester B Veenstra K1YCM MØYCM W8YCM 6Y6Y les...@veenstras.com 452 Stable Ln (HC84 RFD USPS Mail) Keyser WV 26726 GPS: 39.336826 N 78.982287 W (Google) GPS: 39.33682 N 78.9823741 W (GPSDO) Telephones: Home: +1-304-289-6057 US cell +1-304-790-9192 Jamaica cell: +1-876-456-8898 -Original Message- From: time-nuts [mailto:time-nuts-boun...@lists.febo.com] On Behalf Of rcb...@atcelectronics.com Sent: Tuesday, July 21, 2020 7:37 PM To: time-nuts@lists.febo.com Subject: [time-nuts] WWVB PM Time Questions I want to decode the WWVB time information using the BPSK information that is broadcast. I will use a STM32 to do the actual decoding of the bit stream. This is just an exercise in "can I do it?" as I know I can buy clocks for $30 that use the BPSK method. At one time you could buy an IC that output the data stream but I believe there is nothing currently available to do that. I read the document "Enhanced WWVB Broadcast Format" by John Lowe from NIST. One thing that is confusing to me is this paragraph: "Although the phase representing the information in each symbol is shown to be available before the amplitude in it transitions from VH to VL, it is recommended that receivers extract it only from the high amplitude portion of the symbol. This is not only because of the higher power there, allowing for more robust phase demodulation, but also because the low amplitude portion may be used in the future for additional (higher rate) phase modulation." How would you detect the phase had changed if you don't detect it when it changes at 100 msec after the carrier level drops? After the signal reverses phase wouldn't any reference you are using then be in lock with the current phase of the signal after it has changed? Or would you use a locally generated 60 kHz ultra stable signal as the phase reference? If so, how would you keep your local source locked to the 0 degree phase signal of WWVB and have it ignore the 180 degree phase shift? I have done a lot of searching and reading from various sources. But I haven't really found a good explanation of the hardware that would be used to detect the phase changes. Is there a block diagram somewhere that would illustrate the steps needed to detect the change during the high power portion of the WWVB signal? I am going to put together a 60 kHz amplifier using a couple of FET/transistors and a couple of high speed opamps. Then I can observe the signal on my scope. Using the output of the amp I can then try to figure out the best way to detect the phase changes. I can use my AWG to supply the local 60 kHz signal source. I have found two articles that give me some ideas. One is the Nov/Dec QEX article by John, KD2BD and the other is an article titled WWV de-PSK-r by Paul, WB8TSL. Paul is a member of this list. Can someone make other suggestions that will get me pointed in the correct direction? Thanks, Ray, AB7HE ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] WWVB PM Time Questions
Hey Ray, Paul and I have a nice piece of code that generates the WWVB BPSK bit stream using an Arduino and a ublox GPS module. (total cost under $30) You could use this as a WWVB emulator while you're working on your code. Sorry, I can't really help with your question about demodulating the WWVB BPSK but the Costas loop sounds like the way to go. It has also been suggested that a WWVB SDR wouldn't be too difficult to build and would open up lots of possibilities. Unfortunately, I don't have a clue where to begin with that. Maybe somebody with some SDR experience can chime in. Re your comment about $30 BPSK clocks. The only clock I'm aware of that uses the BPSK is the Lacrosse Ultratomic. Are you aware of any others? Thanks, Rodger -Original Message- From: time-nuts On Behalf Of rcb...@atcelectronics.com Sent: Tuesday, July 21, 2020 11:52 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] WWVB PM Time Questions Paul, thanks for the suggestions. The top of the minute is a good idea. Since the first second is part of the sync pattern it will always be 0 and the phase would be 0. A differential opamp with one input from WWVB and the other from the local source fed to the STM32 would tell if the signals were in phase. A single gate inverter controlled by the STM32 could be used to invert the local source if necessary. I have worked with the Bluepill for the last year on a few small projects. The most complex one (which isn't really complex) was to control two stepper motors. I really like the boards and you can't beat the prices. I don't use the bootloader so I have no experience with it. Dana, I looked at the Costas loop and had sort of ruled it out. I may take another look at it as I get further into the project. I will probably use a 15.360 MHz oscillator and divide by 256 to get the 60 kHz local source. Once I get the front end working I will be able to start some "real" testing. Suggestions from others are welcome. Ray, AB7HE ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] IFCS 2020 tutorial - low noise electronics for time/frequency metrology
Hi The gotcha is that all X7R tells you is that the temperature dependence of the part falls inside a certain set of limits. Back many decades ago there were very few formulas out there to make this or that spec part. Pretty much everybody made a part type with the same material. Since the material was the same, you could predict things like RF performance or microphonics off of the temperature characteristic. The generalization that this or that sort of part would work as a bypass at this or that frequency held across multiple manufacturers. As far back as the 80’s this started to change. We would find that this manufacturer produced an X7R part that simply stopped being a capacitor in the HF region . Just how they managed that … who knows. Needless to say, sister company or not, off the AVL with them. Bottom line is that some (most) X7R’s do quite well as RF bypasses up into at least the VHF range. Some are horrid for microphonic, others are quite good. Testing is your friend in this case. Since the material (on a specific part) does not change very often, you can check parts out and then have some confidence in your design. Bob > On Jul 22, 2020, at 4:43 AM, Magnus Danielson wrote: > > > On 2020-07-22 03:39, Richard (Rick) Karlquist wrote: >> >> >> On 7/21/2020 4:27 PM, Magnus Danielson wrote: >> >>> >>> In capacitors, two things make them microphonic, voltage over the >>> capacitor and the high-dielectric constant as this makes it more >>> sensitive to mechanical stress, and this also tends to make them very >>> sentistive to thermal stress. So X7R is terrible for instance. >>> >> >> The LT3042/LT3045 data sheets should be of interest in this regard. >> ADI calls out a particular Murata capacitor that supposedly has low >> microphonics. However, I believe its tempco is X7R, so I can't >> reconcile that with what you said. It does lose less capacitance >> at higher voltages than any other capacitor with a value of 10 uF >> that I have seen, so from what you are saying, this should give >> it lower microphonics. > I was noting a general tendence, but there can be exceptions from the > rule naturally. >> >> Unfortunately, this technology appears to have been orphaned by >> Murata, receiving the dreaded NRND notation. It appears that >> it will be available in distribution for the immediate future >> at least. > > Another problem, it can be hard to depend on too exotic components, as > they can be end of life before your design is, if you are too dependent > on them, large redesign or end of life remains the options. > > Cheers, > Magnus > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] IFCS 2020 tutorial - low noise electronics for time/frequency metrology
On 2020-07-22 03:39, Richard (Rick) Karlquist wrote: > > > On 7/21/2020 4:27 PM, Magnus Danielson wrote: > >> >> In capacitors, two things make them microphonic, voltage over the >> capacitor and the high-dielectric constant as this makes it more >> sensitive to mechanical stress, and this also tends to make them very >> sentistive to thermal stress. So X7R is terrible for instance. >> > > The LT3042/LT3045 data sheets should be of interest in this regard. > ADI calls out a particular Murata capacitor that supposedly has low > microphonics. However, I believe its tempco is X7R, so I can't > reconcile that with what you said. It does lose less capacitance > at higher voltages than any other capacitor with a value of 10 uF > that I have seen, so from what you are saying, this should give > it lower microphonics. I was noting a general tendence, but there can be exceptions from the rule naturally. > > Unfortunately, this technology appears to have been orphaned by > Murata, receiving the dreaded NRND notation. It appears that > it will be available in distribution for the immediate future > at least. Another problem, it can be hard to depend on too exotic components, as they can be end of life before your design is, if you are too dependent on them, large redesign or end of life remains the options. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
