Re: [time-nuts] What's available in the way of DSP for new WWVB?
There are inexpensive CODECs or A-->D converters that are designed for audio, that can be clocked up to 192 ksps or 200 ksps with 24 bit resolution. (Typically 18 or 19 effective bits, 3.0 V p-to-p full scale) They have built in Nyquist filters that scale with the sampling frequency, so a Nyquist frequency of 100 kHz is very comfortable for receiving a 60 kHz signal. They use standard I2S audio interface, although other interfaces are typically options. After that it is SMOP, as they say. (Simple Matter Of Programming). :-) --- Graham == On Fri, Oct 9, 2020 at 12:58 PM paul swed wrote: > after the bpsk is removed true. I have done that. A simple RC filter and a > 100K over 50ohm divider to get the signal to a reasonable level. Add a > coupling cap because all of the old receivers output a preamp voltage. > > On Fri, Oct 9, 2020 at 11:35 AM Bob kb8tq wrote: > > > Hi > > > > For a full setup, you could do it a lot of ways. A setup of: > > > > Antenna -> front end -> ADC -> MCU -> D/A would be one approach. Various > > bits like a local clock also would get into the design. There are *many* > > other > > approaches. > > > > == > > > > There are a lot of D/A’s that will clock in the 100’s of KHz range. If > you > > are only > > trying to come up with an analog of a WWVB signal the “10 bit” D/A’s > found > > in > > some MCU’s would do the trick. In the setup above, the ADC would likely > be > > harder to come up with than the DAC. > > > > Since you are only trying to come up with a carrier, the need for a D/A > is > > not > > an absolute one. Taking a square wave of some sort and filtering it a bit > > would > > be adequate to drive most of these old WWVB receivers. > > > > Bob > > > > > On Oct 8, 2020, at 11:42 PM, Hal Murray > wrote: > > > > > > > > > I assume it needs an antenna, front end, and D/A. > > > > > > What's available in the way of D/A that's good for 60KHz? Is the > > problem > > > easier if the D/A box has external clocking? > > > > > > -- > > > 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 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 SDR discussion
I just purchased 2 of those La Crosse 14" clocks and was totally amazed. I live on the Jersey shore on one acre surrounded by trees and about 8 miles from the ocean. After I placed batteries in the clock, it went through its initially routine which was neat in itself, and about an hour or less later the motors purred again and it went to the exact time and continues to do so. This was on the first floor of my Colonial in my office next to the computer and all sorts of other digital and switching PS noise and only about a foot off the floor. My old Junghans Mega 1000 could never do that. I have to take it upstairs with me and place it by the front (South facing) window of the master bedroom and sometime during the night it acquires and corrects if need be. Regardless, I still like my Junghans, but this new waveform is amazing. Thanks for mentioning it. Regards - Mike Mike B. Feher, N4FS 89 Arnold Blvd. Howell NJ 07731 848-245-9115 -Original Message- From: time-nuts On Behalf Of Tom Van Baak Sent: Tuesday, August 11, 2020 6:45 AM To: time-nuts@lists.febo.com Subject: Re: [time-nuts] WWVB SDR discussion Ray, I don't see a crystal filter. There is a 16 MHz crystal, but that's for the processor. "Inside the La Crosse 1235UA UltrAtomic Radio Controlled WWVB (Atomic) Wall Clock" <http://leapsecond.com/pages/ultratomic/> http://leapsecond.com/pages/ultratomic/ "ES100 datasheet, including block diagram, application circuit, and theory" <http://leapsecond.com/pages/es100/ES100DataSheetver0p97.pdf> http://leapsecond.com/pages/es100/ES100DataSheetver0p97.pdf "Universal Solder ES100 cob dev kit" <http://leapsecond.com/pages/es100/pins.htm> http://leapsecond.com/pages/es100/pins.htm /tvb On 8/10/2020 11:09 PM, <mailto:rcb...@atcelectronics.com> rcb...@atcelectronics.com wrote: > Does the La Crosse UltrAtomic clock actually use a crystal filter or > do they digitally filter the signal? Has anyone ever looked inside of > one of the clocks? Just curious. > > Ray > AB7HE > ___ time-nuts mailing list -- <mailto:time-nuts@lists.febo.com> time-nuts@lists.febo.com To unsubscribe, go to <http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com> 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
Hello to the group. It is really hard to see. I have seen it and it is as the NIST document states. It happens maybe every second or so out of 60-120K cycles I used a HP 3335 that allowed me to slew the phase. Its really hard to catch. Trace up very bright also. Regards Paul On Mon, Jul 27, 2020 at 8:08 PM Dana Whitlow wrote: > That phase reversal when the waveform is not at a zero crossing probably > adds appreciably > more high frequency content than a phase reversal at a zero crossing. In > ham parlance, > I'd say it would introduce pretty severe "key clicks". > > Have you considered writing a program to generate the right waveform to > load into your > AWG? Then you'd have complete control. > > Dana > > > On Mon, Jul 27, 2020 at 6:08 PM wrote: > > > I have been playing with the 74HCT4046 PLL over the last couple of days. > > I have the VCO running at 90 Hz and my AWG running at 90 Hz as the input > > source to lock the loop. The AWG is modulating the 90 Hz sine wave with > > a PSK signal at a 9 Hz rate. > > > > I slowed the signals down from 60 kHz to 90 Hz to better observe the > > phase reversal. I could see the reversal at 60 kHz but could not capture > > it for a single sequence photo. Attached is the jpg of what the signal > > looks like when it performs a 180 degree reversal. With my AWG the > > reversal always occurs at the top or the bottom of the sine wave instead > > of at the center like John Lowe shows in the WWVB document. > > > > I ordered parts from Mouser this morning to build the RF front end. > > Hopefully I will be able to get a clean enough sine wave from WWVB to > > see what their phase reversal actually looks like. Then I will have to > > come of with the best/simplest way to detect the change. As was > > previously mentioned, the normal phase needs to be detected at the top > > of the minute. That means it will take at least 2 and probably 3 minutes > > to obtain a valid date/time data transmission. > > > > 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
Paul, I wasn't talking about putting the d-psk-r software on the Blue Pill board. The d-psk-r software will be on the Arduino board. What I was thinking of doing was putting a single NEMA message on the Blue Pill board. Then connect the UART transmit line to the Arduino in place of the GPS UART line. That way I could send the same NEMA message without having it change every minute. I would count 60 (or maybe 62) pps coming from the GPS and I would know the Arduino was ready for the next NEMA message. Initially I will use the GPS UART transmit line to confirm the Arduino/GPS combo works. Then play with sending my own NEMA GPRMC message from the Blue Pill board. It appears your software simply reads the TX buffer of the GPS until it is empty once per minute and then proceeds to parse the NEMA time/date information out one bit per second. However, the La Crosse Ultratomic clock would not work with this data stream since you are stripping the phase reversals out. Is that correct? I want to extract the time information only. So I would feed the 60 kHz sine wave into the preamp wire on the flipper board. Is that correct? Ray, AB7HE Original Message Subject: Re: [time-nuts] WWVB PM Time Questions From: paul swed Date: Thu, July 30, 2020 5:14 pm To: Discussion of precise time and frequency measurement Ray Are you speaking to the d-psk-r software? Its quite a bit more involved than what you mentioned. Its in the coding sequence. But could it be put on a bluepill absolutely. Its worked on all of the arduinos we have tried. The other thing is that by feeding a 60 KHz CW signal into the d-psk-r modulator/flipper it turns the signal into a wwvb bpsk signal. No AM modulation. But for bench testing its a noise free signal. But I am interested in the approach you are trying to develop that I guess might be a SDR solution. Good luck looking forward to your success. Regards Paul. ___ 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] NIST
My favorite RFI (Request for Information): https://www.fbo.gov/index?s=opportunity=form=4f5c8b176af03d89abb1a318624c944b=core&_cview=0 The public comments should be around someplace. Larry Sampas On Fri, Aug 10, 2018 at 5:05 PM, Andy Backus wrote: > I have a very simple circuit for a (microwatt) 60 kHz transmitter that > takes a digital input (only needs someone to calculate out the WWVB code > from a GPS clock). The biggest problem I find with my WWVB clocks is > getting a good signal, which is highly depend on location in the house and > orientation of the device's antenna. So I have one WWVB receiver in a good > place and key my little transmitter as a "translator" elsewhere in the > house. > > > Andy Backus > > > > From: time-nuts on behalf of Dana > Whitlow > Sent: Friday, August 10, 2018 1:34 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] NIST > > I wonder if anybody will market a GPS-to-WWVB translator? > > Dana > > > On Fri, Aug 10, 2018 at 2:45 PM, Robert LaJeunesse > wrote: > > > I'd say it does get more detailed, with the $49M in cuts described > > generally in groups here: > > > > https://www.nist.gov/director/fy-2019-presidential-budget- > > request-summary/fundamental-measurement-quantum-science-and > > > > One item: "-$6.3 million supporting fundamental measurement > dissemination, > > including the shutdown of NIST radio stations in Colorado and Hawaii" > > > > Looks like some of your friends might be looking for work. Not good. > > > > Bob L. > > > > > > > Sent: Friday, August 10, 2018 at 3:11 PM > > > From: "Magnus Danielson" > > > To: time-nuts@lists.febo.com > > > Cc: mag...@rubidium.se > > > Subject: Re: [time-nuts] NIST > > > > > > Bert, > > > > > > The closes I come is this, burried in the line of Funamental > > Measurements: > > > https://www.nist.gov/fy-2019-presidential-budget-request- > > summary/budget-tables > > > > > > It doesn't get more detailed than that. > > > > > > The T work is relatively small group in the big NIST. > > > > > > Cheers, > > > Magnus > > > > > > On 08/10/2018 08:29 PM, ew via time-nuts wrote: > > > > > > > > NIST total budget for 2017 was close to 965 Million, I was curios > > trying to find out what the Time and Frequency Division portion was. No > > Luck. Does any one know?Thanks Bert Kehren > > > > ___ > > > > 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. > ___ > 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] Loss of NIST transmitters at Colorado and Hawaii
Group, This subject needs some additional detail. I found an article with comments at https://swling.com/blog/2018/08/nist-fy2019-budget-includes-request-to-shutdown-wwv-and-wwvh/ It is not clear whether WWVB will still be available for all of our cheap "atomic" clocks. One comment says that White House budgets are usually ignored in congress. Another says that it is NIST that cut WWV and WWVH, not the White House. Can anyone clarify the situation? Bill Hawkins Sent from my retirement home in MN Change causes confusion until new methods are learned, and a deep sense of loss when something familiar goes away. ___ 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 and Chronverter update
I like Paul's idea, although there may be a risk of the LED's drive signal not being accurately timed. Driving that LED accurately may have had a low priority in the programmer's mind. This should be independently checked for critical applications. Dana On Fri, Aug 24, 2018 at 8:23 AM paul swed wrote: > Thank you for the responses. > I have not reached out to him yet. Want to see if there are other issues > and I can easily add an external 60 KHz source and modulator right now to > verify the other functionality. > There is no schematic nor source code its a 8 pin uproc chip and as such > has almost no IO. I can easily see a very simple fix but needs a change to > the code behavior. (The chip it self can not do the modulation function. > Thats why its OOK). > But if the carrier were left on there is a LED that blinks to the time code > sequence and that can drive a 1 transistor or diode modulator. > Regards > Paul > WB8TSL > > On Fri, Aug 24, 2018 at 3:14 AM, Dana Whitlow > wrote: > > > Is there a schematic published for the Chronverter? I agree with Didier > > that the > > OOK issue *ought *to be pretty easy to fix, and I'd like to look into > that > > myself. > > > > Dana > > > > > > On Thu, Aug 23, 2018 at 9:00 PM Didier Juges wrote: > > > > > Have you tried to contact the manufacturer? It sounds like something > that > > > should be easy to fix and that he would want to fix. > > > > > > Didier KO4BB > > > > > > On Thu, Aug 23, 2018, 8:55 PM paul swed wrote: > > > > > > > Hello to the group. > > > > Had sometime to hook up the chronverter wwvb simulator. > > > > Numbers of details. > > > > The software and operation are clear. > > > > Everything is easy to setup. > > > > Bad news. > > > > Though the system when set to wwvb puts out a signal on 60Khz its on > > off > > > > keying. > > > > WWVBs signal is reduced carrier by some 14db. > > > > As such any of the WWVB clocks of quality/phase tracking do not lock > > and > > > do > > > > not decode. > > > > I have not tried the cheap clocks yet that I suspect will work. > > > > The actual carrier out is a healthy 0 dbm. > > > > > > > > Some issues with commands and the system seeming to lock up requiring > > > power > > > > cycles. > > > > > > > > With respect to the carrier. The chronverter is elegant in the fact > > that > > > it > > > > can generate the 60 KHz frequency and other LF signals. But I will > need > > > to > > > > add an external 6 MHz oscillator divider and modulator if I want to > use > > > it > > > > with the good receivers. > > > > Adds power and complexity. > > > > Regards > > > > Paul > > > > WB8TSL > > > > ___ > > > > 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. > ___ 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] WWV, WWVB and Daylight Savings Time
ke9h.gra...@gmail.com said: > If both the HF and LF signals go away due to the proposed budget cuts, what > is the next simplest way (for something like a microprocessor based clock) to > get DST information? "microprocessor" isn't a well defined term. If you have an OS, use the time conversion package. They all use the same collection of zone info files. If you don't have an OS, use a system with an OS to pre-compute the switch-dates for the next N years and store them in a table. You will have to update that table whenever Congress screws with things. -- 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.
Re: [time-nuts] WWV, WWVB and Daylight Savings Time
Good Idea, John. I'll do that. Just to see what they say. --- Graham == On Fri, Aug 24, 2018 at 1:25 PM John Marvin wrote: > > Someone suggested scraping the NIST time service website for this > information. The NIST website specifically says "Also, it is > inappropriate to generate your own software to use the functionality of > this site. Contact us for details." > It might be interesting to send an email to timei...@boulder.nist.gov > and ask them what they would suggest for getting accurate DST > information, but I doubt they will suggest anything that hasn't already > been proposed. > > Regards, > > John > > > ___ 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 Chronverter update progress
Hi You can do the 14 db deep modulation with a tristate gate and a pair of resistors. Ground the input and feed the “modulation” signal to the tristate control. Bob > On Aug 25, 2018, at 4:35 PM, paul swed wrote: > > From the earlier threads OOK modulation does not work for high end clocks > like spectracoms and truetimes. Have not tried it on the cheapy clocks yet. > > I added an external modulator. A dg419 analog switch and then with a few > resistors added DC offset and anttenuation so that the carrier drops by -14 > db per the wwvb spec. The logic control is driven from the chronverter and > it totally works. Spectracom Netclock 2 locked up in the normal time. > There are far better modern single supply analog gates that will work. Just > did not have any. > > The 60 KHz carrier is supplied by a fluke 6060 generator. This eliminates > any chance of being off frequency and is not the long term answer. > > The chronverter actually uses a dallas semiconductor clock chip thats > reasonably accurate.(dangerous to say on time-nuts) So that even if you do > not add the GPS receiver it will run quite some time correctly after > setting the time. > > Chronverter draws 6 ma from a 5 V supply. I always like low power. > > All in all a very nice answer to what do we do if WWVB goes away. > As mentioned it handles timezones and DST and you can change DST if those > silly politicians screw with it again. > > Speculation > The chronverter actually puts out carriers for the popular LF stations > along with the time codes for them. > > Though the modulator allows quality clocks to lock I speculate the > frequency from the chronverter is not tight enough. All of these clocks > have very sharp crystal filters in them. 10 Hz. Plan to measure the output > of the chronverter see what the 60 KHz is actually at. Though listening on > a HP3586 receiver it appears pretty close to frequency maybe its just not > good enough. Or the fact is OOK modulation does not work because it gaps > the PLL in these clocks. > > Next steps > > - Determine and lay to rest the OOK/need for external modulator. > - Power amplifier and loopstick transmitting antenna staying at or below > 30uv@30 meters. > - Integrate a neo6 GPS receiver in. (Seriously easy) > - > - Box it up. > > Have my eye on one of the Truetime DC468 units and the classy panelplex > display. > > Hope this helps those of you concerned with what to do should WWVB go away. > Regards > Paul > WB8TSL > ___ > 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 Chronverter update progress
Bob The generator sig is 60 Khz sinewave.but as a I build up a divider chain and such your idea makes great sense. Then filter to 60 KHz. But I see the issue with the Chronverter carrier its 120-150 Hz high. Bounces around a fair amount. There could be a secondary issue in that the carrier may not actually be phase stable. It really doesn't matter as for the Truetimes and Spectracoms its simply not good enough. I still need to try the cheapy clocks as that is what it was intended for. Not throwing stones as so much of what it does saves me a bunch of coding and doing exactly what Dave did. Regards Paul WB8TSL On Sat, Aug 25, 2018 at 5:31 PM, Bob kb8tq wrote: > Hi > > You can do the 14 db deep modulation with a tristate gate and a pair of > resistors. > Ground the input and feed the “modulation” signal to the tristate control. > > Bob > > > On Aug 25, 2018, at 4:35 PM, paul swed wrote: > > > > From the earlier threads OOK modulation does not work for high end clocks > > like spectracoms and truetimes. Have not tried it on the cheapy clocks > yet. > > > > I added an external modulator. A dg419 analog switch and then with a few > > resistors added DC offset and anttenuation so that the carrier drops by > -14 > > db per the wwvb spec. The logic control is driven from the chronverter > and > > it totally works. Spectracom Netclock 2 locked up in the normal time. > > There are far better modern single supply analog gates that will work. > Just > > did not have any. > > > > The 60 KHz carrier is supplied by a fluke 6060 generator. This eliminates > > any chance of being off frequency and is not the long term answer. > > > > The chronverter actually uses a dallas semiconductor clock chip thats > > reasonably accurate.(dangerous to say on time-nuts) So that even if you > do > > not add the GPS receiver it will run quite some time correctly after > > setting the time. > > > > Chronverter draws 6 ma from a 5 V supply. I always like low power. > > > > All in all a very nice answer to what do we do if WWVB goes away. > > As mentioned it handles timezones and DST and you can change DST if those > > silly politicians screw with it again. > > > > Speculation > > The chronverter actually puts out carriers for the popular LF stations > > along with the time codes for them. > > > > Though the modulator allows quality clocks to lock I speculate the > > frequency from the chronverter is not tight enough. All of these clocks > > have very sharp crystal filters in them. 10 Hz. Plan to measure the > output > > of the chronverter see what the 60 KHz is actually at. Though listening > on > > a HP3586 receiver it appears pretty close to frequency maybe its just not > > good enough. Or the fact is OOK modulation does not work because it gaps > > the PLL in these clocks. > > > > Next steps > > > > - Determine and lay to rest the OOK/need for external modulator. > > - Power amplifier and loopstick transmitting antenna staying at or > below > > 30uv@30 meters. > > - Integrate a neo6 GPS receiver in. (Seriously easy) > > - > > - Box it up. > > > > Have my eye on one of the Truetime DC468 units and the classy panelplex > > display. > > > > Hope this helps those of you concerned with what to do should WWVB go > away. > > Regards > > Paul > > WB8TSL > > ___ > > 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 Signal Generator
I hope that those of you who write code to generate the WWVB signals in real time from a GPS receiver's output will publish well documented source listings. I for one want to learn how one does this kind of thing in 'C', both for general interest and for this specific application. Thanks, Dana On Wed, Aug 29, 2018 at 3:36 AM Wayne Holder wrote: > As a follow up, I now have a simple WWVB simulator written in C that's now > running an an ATTiny85 using nothing more than the internal, 8 > mHz oscillator and about a 6 inch length of wire connected to one of the > pins as an antenna. It generates an approximate 60 kHz signal using PWM on > timer 1. I tweaked the timer value a bit to correct for some variance in > the internal oscillator, but I' not even sure that was necessary, as my > target is just a BALDR Model B0114ST, consumer grade "Atomic" clock. > Modulation is done by varying the duty cycle of the PWM to approximate the > -17 dBr drop on the carrier. But, again, I don't think this value is > critical with a consumer clock chip. I tapped the demodulated output > inside the clock and displayed it on my scope along with the generated > signal and I got good, steady demodulation with the wire antenna just > placed near clock. The next step is to connect up a GPS module and add > code to use it to set the time. I'm also going to change the code to use > the PPS signal from the GPS to drive the output timing rather than the test > code I have now that uses timer 0 to generate the PPS interrupt. I'm happy > to share details if anyone is interested. > > Wayne > > > > On Sun, Aug 26, 2018 at 2:51 PM, paul swed wrote: > > > That would be a great neighbor to have but I can tell you around here its > > the phone. Not to concerned about someone putting up a wwvb replacement. > > And I can always up the power. Chickle. > > Regards > > Paul > > > > On Sun, Aug 26, 2018 at 2:34 PM, Bob kb8tq wrote: > > > > > Hi > > > > > > The gotcha is if you have neighbors two or three doors away that *also* > > > put up one of > > > these devices. You then have a real problem with the neighbor(s) in the > > > middle. The > > > wavelength is long enough that Raleigh issues won’t get you. You still > > > have the two > > > signals ( at slightly different frequencies) beating against each > other. > > > The result is > > > going to show up as who knows what to this or that receiver. With a > > > precision receiver, > > > you might even have issues from the guy two houses away …... > > > > > > Bob > > > > > > > On Aug 26, 2018, at 1:08 PM, paul swed wrote: > > > > > > > > Agree with the conversation. With respect to neighbors when the day > > comes > > > > they may ask you to boost your signal. :-) > > > > Granted maybe the day won't come but at least having your local > clocks > > > work > > > > is nice. > > > > Regards > > > > Paul > > > > WB8TSL > > > > > > > > On Sat, Aug 25, 2018 at 10:29 PM, Dana Whitlow < > k8yumdoo...@gmail.com> > > > > wrote: > > > > > > > >> With the watch being physically close to the faux WWVB > "transmitter", > > > one > > > >> is in > > > >> the so-called "near field" regime, where the field strength (V/m) > > falls > > > as > > > >> the inverse > > > >> cube of the distance. If one is putting the watch, say, within a > few > > > >> inches of the > > > >> transmitter, reliable reception should be available yet the signal > > > should > > > >> be literally > > > >> undetectable by any practical receiving device more than a few feet > > > away. > > > >> Hence, > > > >> meeting the FCC field strength limit should be trivial.if the device > > is > > > >> used as pictured. > > > >> However, if one cranks up the power enough to reliably cover one's > > > entire > > > >> house, > > > >> then there might be a problem depending how close the nearest > neighbor > > > >> lives, > > > >> even at levels well within the FCC limit he quotes. > > > >> > > > >> Taking the near field relationship in hand, 40 uV/m at 300m would > > > translate > > > >> into > > > >> a whopping 0.135 V/m at 20 meters range, more than enough to feed > most > &g
Re: [time-nuts] NIST
Hi Bob: I would disagree in that ease of jamming/spoofing is strongly related to wavelength. That's because antenna efficiency goes down as the size of the antenna gets smaller than 1/4 wave. So, it's easy to make a GPS jammer (1,100 to 1,600MHz) since a 1/4 wavelength is a few inches, something that you can hold in your hand. It's harder to make a WWV jammer (.5, 5, 10, 15, 20 MHz) since a 1/4 wavelength in in the range of 500 to 12 feet, something that can be mounted on a vehicle for the higher frequencies. But it's extremely hard to make a jammer for WWVB (60 kHz) where a 1/4wavelength is over 4,000 feet. This means an antenna that can be vehicle mounted will be very inefficient. Note this also means that it's extremely hard to make a Loran-C jammer. Note that the WWVB and LORAN-C transmitters run very high power and the antennas are massive. This also means that if someone makes a WWVB simulator for their house the signal at the next door neighbor's house is probably going to be too small to effect their clocks. PS. Some decades ago I maintained a beacon transmitter "LAH" on 175 kHz where the rules for unlicensed operation limited the input power to 1 Watt and total antenna length to 50 feet. Under these conditions the effective radiated power might be 2 milliwatts, orders of magnitude less if a portable system. http://www.auroralchorus.com/pli/1750meter_antennas.pdf -- Have Fun, Brooke Clarke, N6GCE https://www.PRC68.com https://www.end2partygovernment.com/2012Issues.html axioms: 1. The extent to which you can fix or improve something will be limited by how well you understand how it works. 2. Everybody, with no exceptions, holds false beliefs. Original Message Hi When infastructure GPS *does* get jammed these days that source gets tracked down a lot faster than a month or so. Anything that goes on for more than a day gets booted up pretty high pretty fast. Indeed I’ve been in the middle of that more than I would have wished to be ….. The same sort of RFI issues that take out GPS from a TV preamp can equally well take out WWVB or WWV. With WWVB, there are a *lot* of 60KHz switching power supplies out there to create problems. There is nothing unique about any of these services in terms of being jam immune. The bigger issue with any of them is spoofing. A proper GPSDO will go into holdover when RFI jammed. I would *assume* the same would be true of a fancy WWVB device. I’m not at all sure that’s true of a real WWVB standard, they haven’t been for sale new for a really long time. If your time source is in holdover, you can go out and track down the issue. If it simply locks to the new signal …. not so much. There is a subtle distinction in some of this. Newer systems do indeed want time. Older systems were generally after frequency. The only WWVB standards I’ve seen were aimed at frequency (and frequency holdover) rather than time and time holdover. Getting reasonable (1 to 10 ppb) frequency from WWVB is a very different task than getting the sort of time that modern systems are after. Bob On Aug 30, 2018, at 2:46 PM, Scott McGrath wrote: The port of Long Beach CA was jammed wrt GPS for several months by a malfunctioning 29.95 TV preamplifier on a boat. GPS was completely unusable when this unsuspecting guy was watching TV on his boat. He had quite the surprise when the coasties with guns showed up. The fact is civillian GPS Is trivial to jam and jammers can be bought ‘under the counter’ at any truckstop along with illlegal linear amplifiers. On Aug 30, 2018, at 12:58 PM, Peter Laws wrote: On Mon, Aug 13, 2018 at 8:52 AM Peter Laws wrote: I have yet to hear anyone make a case for retaining the HF system that isn't backed by nostalgia. Still looking for this. Most of the "OMG IF WWV GOES AWAY MILLIONS WILL DIE" posts (elsewhere, not here ... quite ...) are the type of hysteria that is usually reserved for, I don't know, the EMP folks. :-) As for solar flares taking out the various GNSSs ... wouldn't a solar flare only take out the vehicles that were on the "sunny" side of the Earth? Wouldn't the (approximately) half of the SVs that are in the Earth's shadow be unaffected? Serious technical question - I have no idea. One of the responses to my initial message pointed out that the effects of solar flares and CMEs take a while to get from Sol to Sol III and don't arrive all at once, so potentially all GNSS spacecraft could be affected. Since then, I've been poking around for papers on the effect (observed, potential, theoretical) of these events on the Navstar or other GNSS constellations but am not having much luck. I assume it's because I'm not putting the right magic incantation into the google machine. Anyone got some cites? Looking for the effect of solar flares and CMEs on the spacecraft themselves and not how the GNSSs can be used to measure the effects on the ionosphere, etc (t
Re: [time-nuts] Lots of Off Topic discussion
Try receiving wwv or wwvb with your HP3586 SLV and determine precisely where f(o) is. It's difficult, ...as propagation and atmospheric conditions will unwittingly prevail. This ham prefers my gpsdo's, or my cesium. Don N5CID = On Sat, 2018-09-01 at 17:04 -0400, William H. Fite wrote: > With respect, Scott, EVERY ham knows about WWV. > > > On Saturday, September 1, 2018, Scott McGrath > wrote: > > > > > I’m concerned with the science > > > > the WWV/WWVB stations provide invaluable information about the > > condition > > of the ionosphere with a baseline of DECADES of data. > > > > Also dont forget that pre PSK the NTP daemon in unix had a > > interface for > > Spectracom WWVB receivers and any retrofitted with a D-PSK’er still > > provide > > network time within all national banking regulations. > > > > As to GPS Jamming well I think its essential that sophisticated GPS > > users > > like this community educate decision makers in their sphere of > > influence > > just how FRAGILE a system GPS is.I realize some dont want to > > hear this > > but its essential that we as a technological society create backup > > systems > > using different techology bases to deliver precise time and > > frequency in an > > economical fashion because not everyone can afford a couple of > > 5071’s. > > > > As to only ‘hams’ using them I dont think many hams unless they are > > running vintage Collins gear with a WWV position on the bandswitch > > to align > > the PTO, even know about WWV. > > > > Most of the WWV users I know personally are atmospheric > > scientists, > > military and other government users. > > > > > > > > Content by Scott > > Typos by Siri > > > > On Sep 1, 2018, at 2:37 PM, Brian Lloyd wrote: > > > > On Sat, Sep 1, 2018 at 9:13 AM, David G. McGaw < > > david.g.mc...@dartmouth.edu> > > wrote: > > > > > > > > I consider saving WWV/WWVH/WWVB to be ON topic. They may not be > > > as > > > precise as some on this list like to achieve, but they are > > > publicly > > > available methods of time dissemination. I am very concerned > > > that > > factions > > > > > > of NIST consider that this should no longer be part of their > > > mission. > > > > > I think it is still on-topic for the following reasons: > > > > 1. In many parts of the world, WWV is still a convenient time > > reference. > > You can get human-accurate time with nothing more than a $20 > > shortwave > > receiver. No, it is not time-nuts accurate but it will do for most > > things > > that people do, including celestial navigation and knowing when to > > come to > > dinner. > > > > 2. It is a stable RF source for people monitoring changes in the > > the > > ionosphere. Whatever else it is, we KNOW they are emitting ON 2.5, > > 5, 10, > > 15, 20, and 25 MHz. > > > > I also consider the discussion of GPS jamming to be relevant > > because, for > > people who DO want/need time-nuts accuracy, GPS is far and away the > > most > > convenient reference. Knowing how it might fail is useful. > > > > YMMV. > > > > -- > > > > > > > > Brian Lloyd > > 706 Flightline > > Spring Branch, TX 78070 > > br...@lloyd.aero > > +1.210.802-8FLY (1.210.802-8359) > > ___ > > 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 Signal Generator
andrewbac...@msn.com said: > Also -- when the GlobalTop loses a fix it still puts out the RMC sentence, > just without the lat and lon data. And the PPS immediately stops. I > designed the parsing scheme to account for that. How long that reporting > would continue I don't know. The RMC sentence has a valid field with an A or V. Some GPS receivers don't stop the PPS when not working. I expect some of them continue with dead-reconing values for lat/lon. -- 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.
Re: [time-nuts] WWVB Chronverter update progress
paul swed writes: > Indeed anything could be used if you want to modify the clocks. I > don't. Fair enough. > They do what they do very well and consume 0 power. Well, I assume there's some sort of battery involved, but anyway, this line of discussion misses the point. Replacing one LF module with another HF module, both powered on for a maximum of half an hour a day shouldn't make much of a difference (as long as you do not use the transmit function of the module, which I can see uses for given the fact that there's nearly always a thermometer and hygrometer in these clocks). > Can be placed in any location in the house or garage and even the basement. > Interestingly without the real wwvb I can orient them any way I want > also. That's some indication that your transmitter may have more power or your general reception of the real WWVB is better than you think. The null on a ferrite rod is pretty steep, so finding no orientation where it stops working seems strange. I have had to open a number of my clocks specifically to reorient the ferrite so I could place them where I wanted. The only clock that didn't have that problem turned out to employ two modules with their antennas at 90° at the opposite sides of the case. Anyway, you don't want to modify the clock and I don't particularly want to build something that might be illegal if anybody can detect and complain about it, even when that chance is very small. > The last thing I want to do is hack them. But like you say if you are > willing to hack a set of 3 wires will do very well. Or just leave them > powered all the time. Many options. Actually, one of the reasons I even brought it up was that many years ago I needed a bunch of clocks driven from a master clock so they'd all show the same time synchronized to the sub-second and they needed to be readable from a fair distance, so their display had to be large. That was for a recording studio, so the electromechanical clocks were out due to the racket they make. The cheapest solution was in fact to have the master clock put DCF77 bits on a telephone wire and then run that into a set of DCF clocks with the biggest LCD that we could find. I didn't even remove the modules, they just never got their enable signal after the modification. The other bit to know about these clocks was that they had slide switches instead of todays typical buttons to set their modes and that meant you could put them into a continous reception mode easily. > But many on time-nuts have these clocks and should wwvb be turned off its > nice to know my weather stations will keep working and have the right time > and far more accurately then my mobile phone. That's why I was curious about their inner workings and if they might be much different than what I know from my side of the pond. > Last comment. Its a time nuts challenge just have to tinker and share. I wasn't commenting about the usefulness of the approach or your (or anyone elses) intentions or anything of that sort. I had hoped it was obvious that this omission was not meant as a back-handed critique, I just had nothing to add to the information that was already shared. But you seem to be offended nonetheless (ever-so-slightly), so I apologize. Regards, Achim. -- +<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+ SD adaptation for Waldorf microQ V2.22R2: http://Synth.Stromeko.net/Downloads.html#WaldorfSDada ___ 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 Signal Generator
Hi If somebody really wanted to go crazy on this, a link just popped up in my inbox: https://www.st.com/content/st_com/en/about/events/events.html/teseo-liv3f-gnss-module-webinar.html?ecmp=tt7108_us_enews_apr2018=stmDM10269=166175037=tEVjzOAFGOno6x6Htwrh8A== <https://www.st.com/content/st_com/en/about/events/events.html/teseo-liv3f-gnss-module-webinar.html?ecmp=tt7108_us_enews_apr2018=stmDM10269=166175037=tEVjzOAFGOno6x6Htwrh8A==> I know zip about the ST chips other than what’s in the link. The webinar is free and at least that’s better than signing an NDA simply to look at the slides ( which some other vendors seem to want you to do). Bob > On Aug 29, 2018, at 4:55 AM, Dana Whitlow wrote: > > I hope that those of you who write code to generate the WWVB signals in real > time from a GPS receiver's output will publish well documented source > listings. > > I for one want to learn how one does this kind of thing in 'C', both for > general > interest and for this specific application. > > Thanks, > > Dana > > > > On Wed, Aug 29, 2018 at 3:36 AM Wayne Holder wrote: > >> As a follow up, I now have a simple WWVB simulator written in C that's now >> running an an ATTiny85 using nothing more than the internal, 8 >> mHz oscillator and about a 6 inch length of wire connected to one of the >> pins as an antenna. It generates an approximate 60 kHz signal using PWM on >> timer 1. I tweaked the timer value a bit to correct for some variance in >> the internal oscillator, but I' not even sure that was necessary, as my >> target is just a BALDR Model B0114ST, consumer grade "Atomic" clock. >> Modulation is done by varying the duty cycle of the PWM to approximate the >> -17 dBr drop on the carrier. But, again, I don't think this value is >> critical with a consumer clock chip. I tapped the demodulated output >> inside the clock and displayed it on my scope along with the generated >> signal and I got good, steady demodulation with the wire antenna just >> placed near clock. The next step is to connect up a GPS module and add >> code to use it to set the time. I'm also going to change the code to use >> the PPS signal from the GPS to drive the output timing rather than the test >> code I have now that uses timer 0 to generate the PPS interrupt. I'm happy >> to share details if anyone is interested. >> >> Wayne >> >> >> >> On Sun, Aug 26, 2018 at 2:51 PM, paul swed wrote: >> >>> That would be a great neighbor to have but I can tell you around here its >>> the phone. Not to concerned about someone putting up a wwvb replacement. >>> And I can always up the power. Chickle. >>> Regards >>> Paul >>> >>> On Sun, Aug 26, 2018 at 2:34 PM, Bob kb8tq wrote: >>> >>>> Hi >>>> >>>> The gotcha is if you have neighbors two or three doors away that *also* >>>> put up one of >>>> these devices. You then have a real problem with the neighbor(s) in the >>>> middle. The >>>> wavelength is long enough that Raleigh issues won’t get you. You still >>>> have the two >>>> signals ( at slightly different frequencies) beating against each >> other. >>>> The result is >>>> going to show up as who knows what to this or that receiver. With a >>>> precision receiver, >>>> you might even have issues from the guy two houses away …... >>>> >>>> Bob >>>> >>>>> On Aug 26, 2018, at 1:08 PM, paul swed wrote: >>>>> >>>>> Agree with the conversation. With respect to neighbors when the day >>> comes >>>>> they may ask you to boost your signal. :-) >>>>> Granted maybe the day won't come but at least having your local >> clocks >>>> work >>>>> is nice. >>>>> Regards >>>>> Paul >>>>> WB8TSL >>>>> >>>>> On Sat, Aug 25, 2018 at 10:29 PM, Dana Whitlow < >> k8yumdoo...@gmail.com> >>>>> wrote: >>>>> >>>>>> With the watch being physically close to the faux WWVB >> "transmitter", >>>> one >>>>>> is in >>>>>> the so-called "near field" regime, where the field strength (V/m) >>> falls >>>> as >>>>>> the inverse >>>>>> cube of the distance. If one is putting the watch, say, within a >> few >>>>>> inches of the >>>>>> transmitter, reliabl
Re: [time-nuts] WWVB Signal Generator
For those that have asked for my to publish the source code for my ATTiny85-based WWVB simulator, I have put up a somewhat hurriedly written page on my google site at: https://sites.google.com/site/wayneholder/controlling-time that describes a bit about how the code works, how to compile it using the Arduino IDE, how I tested it, some issues I have observed in testing it and, at the bottom of the page, a downloadable zip file that contains the complete source code. Note: as mentioned at the top of this page, this is currently a work in process, so I'm not yet going to link the article to my main website page, so you'll need to link in this post to find it. Also, as draft, I'm going to continue to revise the page until I feel the project is complete enough to publish. That means the source code zip file is going to potentially change from time to time, too. Wayne On Wed, Aug 29, 2018 at 1:35 AM Wayne Holder wrote: > As a follow up, I now have a simple WWVB simulator written in C that's now > running an an ATTiny85 using nothing more than the internal, 8 > mHz oscillator and about a 6 inch length of wire connected to one of the > pins as an antenna. It generates an approximate 60 kHz signal using PWM on > timer 1. I tweaked the timer value a bit to correct for some variance in > the internal oscillator, but I' not even sure that was necessary, as my > target is just a BALDR Model B0114ST, consumer grade "Atomic" clock. > Modulation is done by varying the duty cycle of the PWM to approximate the > -17 dBr drop on the carrier. But, again, I don't think this value is > critical with a consumer clock chip. I tapped the demodulated output > inside the clock and displayed it on my scope along with the generated > signal and I got good, steady demodulation with the wire antenna just > placed near clock. The next step is to connect up a GPS module and add > code to use it to set the time. I'm also going to change the code to use > the PPS signal from the GPS to drive the output timing rather than the test > code I have now that uses timer 0 to generate the PPS interrupt. I'm happy > to share details if anyone is interested. > > Wayne > > > > On Sun, Aug 26, 2018 at 2:51 PM, paul swed wrote: > >> That would be a great neighbor to have but I can tell you around here its >> the phone. Not to concerned about someone putting up a wwvb replacement. >> And I can always up the power. Chickle. >> Regards >> Paul >> >> On Sun, Aug 26, 2018 at 2:34 PM, Bob kb8tq wrote: >> >> > Hi >> > >> > The gotcha is if you have neighbors two or three doors away that *also* >> > put up one of >> > these devices. You then have a real problem with the neighbor(s) in the >> > middle. The >> > wavelength is long enough that Raleigh issues won’t get you. You still >> > have the two >> > signals ( at slightly different frequencies) beating against each other. >> > The result is >> > going to show up as who knows what to this or that receiver. With a >> > precision receiver, >> > you might even have issues from the guy two houses away …... >> > >> > Bob >> > >> > > On Aug 26, 2018, at 1:08 PM, paul swed wrote: >> > > >> > > Agree with the conversation. With respect to neighbors when the day >> comes >> > > they may ask you to boost your signal. :-) >> > > Granted maybe the day won't come but at least having your local clocks >> > work >> > > is nice. >> > > Regards >> > > Paul >> > > WB8TSL >> > > >> > > On Sat, Aug 25, 2018 at 10:29 PM, Dana Whitlow > > >> > > wrote: >> > > >> > >> With the watch being physically close to the faux WWVB "transmitter", >> > one >> > >> is in >> > >> the so-called "near field" regime, where the field strength (V/m) >> falls >> > as >> > >> the inverse >> > >> cube of the distance. If one is putting the watch, say, within a few >> > >> inches of the >> > >> transmitter, reliable reception should be available yet the signal >> > should >> > >> be literally >> > >> undetectable by any practical receiving device more than a few feet >> > away. >> > >> Hence, >> > >> meeting the FCC field strength limit should be trivial.if the device >> is >> > >> used as pictured. >> > >> However, if one cranks up the power enough to reliably cover one's >> > entire >> > >> house, >&
Re: [time-nuts] More ES100 WWVB Measurements
Hi Wayne: DST. GPS has no bits for Daylight Savings. As far as I know only WWV and WWVB have those bits. So for a clock displaying local time WWVB is the way to go. -- Have Fun, Brooke Clarke https://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html axioms: 1. The extent to which you can fix or improve something will be limited by how well you understand how it works. 2. Everybody, with no exceptions, holds false beliefs. Original Message While reading this thread and pondering whether to buy and fool around with an ES100-based module from Universal Solder, I suddenly found myself wondering if there was any advantage to using the time received from WWVB vs just using an inexpensive GPS receiver. The ES100 module costs about $70, but I can get a GPS receiver, with antenna, for far less than that and I've had no trouble receiving GPS signals indoors with most modern receiver modules. I suppose the low power requirements of the ES100 might be an advantage when building battery powered clocks to mount on the wall, but it seems like some of the newer, ultra low power GPS modules intended for use in smart watches could also work in a battery-powered wall clock, especially if the receiver was only powered on a few times a day to update the time. And, finally, if GPS modules are (or will some become) a suitable replacement for WWVB receiver modules, do we really need WWVB in the modern age? Perhaps there's some critical advantage to using WWVB to get the time but, offhand, I cannot think of it. What am I missing? Wayne On Mon, Dec 31, 2018 at 4:30 PM Brooke Clarke wrote: Hi Joseph: Thanks for the patent link. I've added it to my WWVB phase modulation info at: https://prc68.com/I/Loop.shtml#La_Crosse_UltrAtomic -- Have Fun, Brooke Clarke https://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html axioms: 1. The extent to which you can fix or improve something will be limited by how well you understand how it works. 2. Everybody, with no exceptions, holds false beliefs. Original Message On Mon, 31 Dec 2018 12:00:02 -0500, time-nuts-requ...@lists.febo.com wrote: time-nuts Digest, Vol 173, Issue 44 Message: 7 Date: Mon, 31 Dec 2018 04:04:22 -0800 From: "Tom Van Baak" To: "Discussion of precise time and frequency measurement" Subject: Re: [time-nuts] More ES100 WWVB Measurements Message-ID: <96BB388753294278A9CDE96C1EA7D9AE@pc52> Content-Type: text/plain;charset="UTF-8" Hi Graham, That's very nice work. And you have uncovered several unusual effects in the ES100. Bugs? Features? If we time nuts keep up the good work to evaluate this chip, we are likely at some point to get an informative response from the guys who designed it. They read time-nuts. I didn't see this mentioned, but I think I have found the relevant US patent application: US20130051184A1, Real-time clock integrated circuit with time code receiver, method of operation thereof and devices incorporating the same, Oren Eliezer et al, Oren Eliezer et al, filed 2013-02-28. .<https://patents.google.com/patent/US20130051184> Found this by chasing stuff from the EverSet website: .< http://everset-tech.com/wp-content/uploads/2014/11/ReceiverRadioClocks.pdf . Joe Gwinn So now both you and Tim have observed the off-by-one-second (or off-by-N-seconds) effect in the ES100. I wonder if this explains why some of my ES100-based La Crosse 1235UA Ultratomic wall clocks are off by a second sometimes. My main question: in your "Time Plot.PNG" plot, what is the cause of the sawtooth pattern? The points are almost all on a clear negative slope, though bounded by roughly +/- 75ms. Looking on the far left, I see a time drift of +50 ms to -25 ms over an hour, which is equivalent to a -20 ppm frequency offset; about -2 seconds/day. Do you think this is due to the 16 MHz onboard xtal? If so, how about changing the temperature of the eval board by a lot (say, several tens of degrees) for an extended time (say, 4 hours) and see if the sawtooth slope changes convincingly. Also, just to be sure, can you put a known independent timing signal (e.g., GPS/1PPS) into your complex BeagleBone Black / Debian 9.4 / ntpd time server / Python 3 / Excel stack to establish the validity of your measurement methodology? Very likely you did it right, but I always cringe when I hear "Linux" or "NTP" and "precise time" in the same sentence. Yes, sorry, forgive me; I grew up in the "trust, but verify" generation [1]. It applies pretty well to metrology also ;-) /tvb [1] https://en.wikipedia.org/wiki/Trust,_but_verify End of time-nuts Digest, Vol 173, Issue 44 ** ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
Re: [time-nuts] More ES100 WWVB Measurements
It appears Canada tries to match the US to save confusion. The US changed the dates starting in 2007 (making clocks in earlier systems like VCRs obsolete) and Canada followed suit. Who knows what Congress will do in the future (abolish DST? I hope!), so programming a system to be good to 2100 seems optimistic! David N1HAC On 1/1/19 5:31 PM, Graham / KE9H wrote: >> Does anybody know how many other places use the same rules? What does > Canada do? > > https://en.wikipedia.org/wiki/Daylight_saving_time_by_country > > --- Graham > > == > > On Tue, Jan 1, 2019 at 4:05 PM Hal Murray wrote: > >>> GPS has no bits for Daylight Savings. As far as I know only WWV and WWVB >>> have those bits. So for a clock displaying local time WWVB is the way to >> go. >> >> WWVB's DST data is targeted at the US. >> >> Does anybody know how many other places use the same rules? What does >> Canada >> do? >> >> Has anybody looked into how much code it takes to implement DST? If you >> are >> willing to stick to one set of rules, you could pre-compute a small table >> to >> cover the next 20 (or 100) years. That's probably not good enough for a >> product, but OK for most home brew clocks. Can I get to 2100 with only 28 >> slots? (7 for day-of-week, and 4 for leap years) >> >> The full Unix time conversion package is pretty big if you are of running >> it >> on a tiny SOC. Has anybody implemented a slimmed down version? How slim >> can >> you get if all you want is DST? >> >> Besides, GPS gives you leap second warning. >> >> A while ago, somebody asked why use WWVB rather than GPS? One answer is >> so we >> can monitor what it does when a leap second happens. >> >> >> >> >> -- >> These are my opinions. I hate spam. >> >> >> >> >> ___ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to >> https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Flists.febo.com%2Fmailman%2Flistinfo%2Ftime-nuts_lists.febo.comdata=02%7C01%7Cdavid.g.mcgaw%40dartmouth.edu%7C25a013efe21a47a2cfc308d670673875%7C995b093648d640e5a31ebf689ec9446f%7C0%7C1%7C636819985982409036sdata=BKBILOKTdOaPsSSz%2FezRuZ8His6jcRnp5TePARLlIYs%3Dreserved=0 >> and follow the instructions there. >> > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Flists.febo.com%2Fmailman%2Flistinfo%2Ftime-nuts_lists.febo.comdata=02%7C01%7Cdavid.g.mcgaw%40dartmouth.edu%7C25a013efe21a47a2cfc308d670673875%7C995b093648d640e5a31ebf689ec9446f%7C0%7C1%7C636819985982419040sdata=N7yW%2BmbXlKj47WIeCBKMSjT7628E1dkj33yfQ8yqyjg%3Dreserved=0 > 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] ES100 BPSK WWVB jitter data
In message , Tim Shoppa writes: >I don't see any sawtooth or other weird stuff going on in the residual. I don't think you would be able to detect a sawtooth, even if it were there, with a pulse-per-minute signal between two bare X-tals ? -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@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] new WWVB BPSK dev board
In message , "John Moran, Scawby Design" writes: >I think I will get distracted over Christmas sketching out some designs ... Grab som I+Q samples from a kiwisdr somewhere and start playing with signals instead. If you like it, start making hardware. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@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] new WWVB BPSK dev board
Hi Paul, It was shifted over 11 years ago, very obligingly timed to follow my move from the South East to Scotland:-), so I suspect any resulting propogational changes would have been well documented by now. Nigel GM8PZR Hi thank you Bob for the mail Do you realise the 60 Khz Transmitter in the UK was moved from Rugby in the centre of England north by more than 200 miles Paul ___ 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] new WWVB BPSK dev board
On 12/4/2018 6:29 PM, Gilles Clement wrote: Hi, In France the carrier frequency is 162khz (Allouis) Phase modulated over one minute. Gilles. Interesting: isn't 162 kHz within the European Long Wave Broadcast Band? Wouldn't there be a problem with QRM from these megawatt stations? Excuse the naive questions; we don't have longwave in the states, so no experience here. Rick ___ 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] new WWVB BPSK dev board
On 12/4/18 9:00 AM, Tim Shoppa wrote: Because of the Q of WWVB's transmit antenna (at least 300 by my back of the envelope estimates), I don't think we could ever claim a WWVB PPS edge sharper than 5 milliseconds and that might be optimistic. Sure you can.. you do a matched filter to the waveform, so you're not just looking at a single zero crossing or cycle. Getting fraction of a degree phase accuracy from a strong signal is entirely possible. A Q of 300 implies a bandwidth of 200Hz, which would, if a single section, be a delay of a few milliseconds. But that delay should be constant. What might be the limit on precision is whether the delay through the antenna and the ultimate radiated phase changes with, say, temperature or soil properties. Tim N3QE On Tue, Dec 4, 2018 at 11:49 AM Bob kb8tq wrote: Hi The I2C clock rate is going to matter a bit in terms of what you can achieve. Since the device is targeted at low power, the max practical baud rate may not be very high. I2C can have a lot of wait in it ... There are a lot of registers dumped after each “reception attempt”. There also is the basic question of how the IRQ flag relates to the time the chip “sees”. If it’s actually WWVB time sync’d then that’s a useful thing. None of this is likely to be an issue in a wall clock. If they can run at a “tens of ms” sort of level that’s more than good enough. We really want to get to microseconds don’t we :) Bob On Dec 4, 2018, at 11:25 AM, Majdi S. Abbas wrote: $69 CAD is roughly $50 USD. Expensive for what it is but easier to work with than gutting a working clock and no more expensive. I ordered one. Curious to see what sort of precision we can get from an i2c interface. If nothing else I suppose I can toss a six digit i2c 7 segment module at it and roll my own WWVB desk clock. —msa On Dec 4, 2018, at 07:50, paul swed wrote: I assume thats exactly the case. I also thought it was pretty high. The actual clocks are about $50 or less I believe. So the board seems a bit off. Regards Paul WB8TSL ___ 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] new WWVB BPSK dev board
As was said, IRQ delay is +/-100 mS from the second edge, hardly what a Time-Nut is looking for. David On 12/4/18 1:07 PM, Hal Murray wrote: >> The one thing I wish is that there were access to the synchronized analog >> signal and/or a 1PPS. Even a top of the minute would be useful. It only >> has the I2C digital interface. > It also has an IRQ signal. > > The data sheet said it's 100 ms after the second, but I didn't see any > accuracy info but I didn't look carefully. > > ___ 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] new WWVB BPSK dev board
>We’ve been chatting about how drop dead simple it is to spend a couple minutes >and come >up with a SDR for the new modulation for …. ummm ….. errr …. how many years >now? :) >So far not a lot has turned up. All I can say is that people dont know what they're missing ;-) -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@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] new WWVB BPSK dev board
I also ordered one of the EverSet Dev Boards. Pricey for a one IC "glop-top" package, but I would like to see how it performs. But, I could not duplicate quantity one for the price, either. I also note that they sold out about mid day yesterday, so Tom's announcement cleaned them out. As far as the claimed 20 (ish) dB gain of the BPSK modulation scheme, if you read the papers, it is a system gain, not just a gain from BPSK modulation, involving error correcting coding and extended correlation across six minute sequences. --- Graham > > ___ 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 data to play with
On 12/5/18 4:36 PM, Poul-Henning Kamp wrote: Johns sample-rate appears to be almost 1000PPM fast and drifting, it it is trivial to adjust the "do" to keep either the ali or alq haunting zero. Yes, I should have mentioned that the Red Pitaya does not have a reasonable way to run with external clock, and the internal (TC?)XO is obviously nothing to write home about. If we want stable/accurate data, I can switch to a Hermes board locked to GPSDO or Cs. John ___ 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] 60Khz received on Wide-band WebSDR
Hi, On 2019-07-06 20:39, Poul-Henning Kamp wrote: > > In message > , > "D. Resor" writes: > >>> From another list I was directed to this link for those who do not have a >> shortwave radio. >> >> http://websdr.ewi.utwente.nl:8901/ >> >> I entered the frequency of 60Khz and am curious to know if this the WWVB >> transmission I am hearing or something else? > No, that is the UK Rugby transmitter. > > For SDR transmitters all over the world, mainly John's KiwiSDR, visit > http://sdr.hu > The MSF is not transmitted from Rugby anymore, it's transmitted from Anthorn. 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.
Re: [time-nuts] 60Khz received on Wide-band WebSDR
Hi, On 2019-07-06 20:39, Poul-Henning Kamp wrote: > > In message > , > "D. Resor" writes: > >> >From another list I was directed to this link for those who do not have a >> shortwave radio. >> >> http://websdr.ewi.utwente.nl:8901/ >> >> I entered the frequency of 60Khz and am curious to know if this the WWVB >> transmission I am hearing or something else? > No, that is the UK Rugby transmitter. > > For SDR transmitters all over the world, mainly John's KiwiSDR, visit > http://sdr.hu > The MSF is not transmitted from Rugby anymore, it's transmitted from Anthorn. 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] ES100 suddenly more sensitive in summer!
Interestingly enough, compared to my initial testing last winter, my ES100 is suddenly much more likely to acquire and track WWVB in broad daylight. This morning it is acquiring from a cold start almost every time. (The "bad minutes" of course still don't work). Most likely reason would be some reduction in my local noise sources but wonder if something more propagation-wise is going on. For sure I expected 60kHz propagation from Colorado to Maryland to be more reliable in common darkness and in winter, and less reliable in summertime and common daylight, but perhaps this is a faulty mental model I have. 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.
[time-nuts] spectracom 8170
I have a stack of Spectracom 8170 WWVB synchronized clock boxes, along with the matching antenna and preamp and an RS232 distribution box. I found a little documentation for the antenna and preamp but little else. Wondering if anyone here has any ideas how I might re-purpose them. They have some interesting boards and casework, so I can break them down, but it would be great to re-use them as they are. thanks - bill __ brevity is beautiful. ___ 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] 60Khz received on Wide-band WebSDR
Would likely be the UK MSF signal. /Björn Sent from my iPhone > On 6 Jul 2019, at 14:39, D. Resor wrote: > > From another list I was directed to this link for those who do not have a > shortwave radio. > > http://websdr.ewi.utwente.nl:8901/ > > I entered the frequency of 60Khz and am curious to know if this the WWVB > transmission I am hearing or something else? > > > Donald Resor > N6KAW > > > ___ > 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] 60Khz received on Wide-band WebSDR
In message , "D. Resor" writes: >>From another list I was directed to this link for those who do not have a >shortwave radio. > >http://websdr.ewi.utwente.nl:8901/ > >I entered the frequency of 60Khz and am curious to know if this the WWVB >transmission I am hearing or something else? No, that is the UK Rugby transmitter. For SDR transmitters all over the world, mainly John's KiwiSDR, visit http://sdr.hu -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@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] 60Khz received on Wide-band WebSDR
No longer at Rugby, now at Anthorn: GBR: longitude -3.28latitude 54.91 "Poul-Henning Kamp" wrote: > In message > , > "D. Resor" writes: > > > > From another list I was directed to this link for those who do not > > > have a > > shortwave radio. > > > > http://websdr.ewi.utwente.nl:8901/ > > > > I entered the frequency of 60Khz and am curious to know if this the WWVB > > transmission I am hearing or something else? > > No, that is the UK Rugby transmitter. > > For SDR transmitters all over the world, mainly John's KiwiSDR, visit > http://sdr.hu > -- Brian Duffell YarmEngland ___ 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] can of worms: time-of-day in a community radio station
Regarding analog clocks, what is the groups opinion on these Atomic WWVB Signal Radio Controlled Clock Movements? I ordered one from China but it isn't here yet. I am hoping that I won't have to change the clock for DST. They are only $15. https://www.klockit.com https://www.amazon.com/dp/B07XWTMZZD/ref=cm_sw_r_tw_dp_U_x_VJARDbHBEE15J https://www.aliexpress.com/item/33005680618.html -- Myron ___ 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] eLORAN to turn on next week for a test
Hello fellow time-nuts. Just found out eLORAN will be on next week or so. Bringing Wildwood back on air the week of February 17th and then again the week of March 16th for a demonstration of UTC time synchronization. We’ll be broadcasting as 8970M and 8970X from Wildwood during those times. So if you still have gear and want to warm it up for checking frequency here is your chance. I already know I need to replace a 20' section of a 164' line of RG6 from a squirrel attack. Just replaced 140' of a 174' line due to the same for WWVB. Fortunately thats quite easy to do. Wonder if the pre-amps still good? Regards Paul WB8TSL ___ 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] Bob Roehrig K9EUI SK
Services for our fallen fellow time nut Bob Roehrig are this Saturday January 4, in Batavia, IL. Bob was a member of this list, and many of you may remember him from articles and projects published in 73 Magazine (and others) such as 1994's "Using the World's Most Accurate Frequency Standard" which in great detail he walked through building a WWVB receiver/comparator. He was a brilliant builder and hardly owned a single piece of amateur radio equipment that he didn't build from scratch, or modify. http://www.mossfuneral.com/obituaries/details/2589/Regards,Chris FarleySent via wireless apparatus _._ ___ 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] Spectracom 8161 "Standard Frequency Receiver - Oscillator" for WWVB (and question...)
Burt I like it the "thumpers". The really annoying chart recorders I tend to disconnect. Imagine 2-3! I use a software recorder these days. Quite and consumes 10 X the power but no actual paper. Can't find that anymore at a price you might care to pay for. My other favorite box is the Gertch RLF. Not sure why it caught my eye on the floor at a hamfest but it did and what a bargain with a nice xtal filter. Have to love the RTL logic. We recently republished the details on the new improved dpskr here on time-nuts June approx. Do a search. It does make those old boxes work again without any internal mods. It also handles the fast and slow code. As Bob says you can get interesting accuracy over several days as the papers say even with the propagation. Regards Paul WB8TSL On Mon, Oct 5, 2020 at 11:59 AM Burt I. Weiner wrote: > The 45 degree phase shift was a form of identification for WWVB and > also served as a marker for chart recorders. The shift occurred from > 10-minutes past the hour until 15 minutes past the hour. > > Before GPS came along, WWVB was my main frequency > standard/reference. I had two Gertsch RLF devices and a "thumper" > chart recorder. It was really a lot of grief trying to keep my > relatively poor crystal oscillators on frequency. If I was able to > see the 45-degree shift I felt as though I was really accomplishing > something. :] I now have two DATUM 9390-52054 GPS units. GPS has > really spoiled me! > > Up until the phase shift was added I used a Symmetricom 8170, not so > much as a frequency reference, but as a clock in my shoppe. The 8170 > is still running, but displays some strange combination of numbers > that actually tell me the status of it trying to set. I suppose I > should build a de-psk-er thingy, but I lost the paper work on how to > do it.The 8170 presently serves as a night lite. > > Burt, K6OQK > > At 08:36 AM 10/4/2020, someone wrote: > >Now, there is a 45 degree (2.1 micro) modulation on the WWVB > >signal, > that shows up as time-tags on the strip-chart, so it is > >not trivially... > > Burt I. Weiner Associates > Broadcast Technical Services > Glendale, California U.S.A. > b...@att.net > K6OQK > > > ___ > 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 Dephaser Question
OK then that would be a classic TRF receiver. Very typical be it transistors and coils or opamps. Whats the level on the SA? Now you have entered the nasty territory that can give you many hours of fun. The nast BPSK signal. Look at google for BPSK and costas loop techniques. That will give you insights as to what to do. Essentially lock an oscillator create 2 signals 90 degrees out and mix or sample with those two signals. The math gets really interesting at that point as how to detect the phases. For me thats all clear as mud. On Fri, Oct 9, 2020 at 1:58 PM wrote: > Paul, Bob, > > I am not using any commercial receiver. I am building everything from > scratch. The RF front end starts with a ferrite rod antenna feeding a > differential first op amp followed by 5 stages of op amp filtering and > amplification. When the last stage is fed to my spectrum analyzer > (through attenuators) the WWVB signal is clearly visible. I'm now trying > to figure out how to detect the phase shift so I can get the time data > for my CPU to process and send to a display. > > I already have a GPS based clock that I built so I thought the WWVB > phase clock would be an interesting project. > > Ray > > Original Message > Subject: Re: [time-nuts] WWVB Dephaser Question > From: Bob kb8tq > Date: Fri, October 09, 2020 7:35 am > To: Discussion of precise time and frequency measurement > > > Hi > > At least to me, anything dimensioned in the 100’s of feet is > “massive” compared to > the rod antennas normally seen in WWVB use …. > > The other point being that if the antenna is some sort of large loop, > it’s going to be > a good long ways away from the receiver. You get both a larger signal > voltage and better > isolation ….. > > Bob > > > On Oct 8, 2020, at 11:30 PM, John C. Westmoreland, P.E. < > j...@westmorelandengineering.com> wrote: > > > > Hello All, > > > > Are there any design details someplace regarding these massive antennas? > > > > Thanks, > > John > > AJ6BC > > > > > > On Thu, Oct 8, 2020, 19:27 paul swed wrote: > > > >> Hello to the group. > >> Ray as Bob mentions you are taking a 10s of uv signal to a logic level > of > >> maybe 4V. > >> If the loop is any place close to the divided down signal, it will > >> oscillate. It would take incredible shielding to protect the receiver. > >> Thats why you often see a solution that doubles to 120 KHz and modifies > the > >> detectors to work at that frequency. That means hacking the radio > >> internally. Not fun. The other really annoy effect is that the doubling > >> slips phace due to noise and propagation. So if charting suddenly you > get a > >> 180 degree flip. Thats messy. > >> The doubling solution can work. Search for carter and there are several > >> others. > >> But having tested and used all of the alternates and lots more on the > east > >> coast decided they were too much trouble. You should see the box of > boards > >> I have chuckle. > >> For me I am very happy with the d-psk-r. Though in being above board I > >> designed version 1 and Rodger and I did version 2. Its solid and no > mods to > >> any receiver. Everything has always been released to the time-nuts > group. > >> As they say have fun. > >> Regards > >> Paul. > >> WB8TSL > >> > >> On Thu, Oct 8, 2020 at 5:39 PM wrote: > >> > >>> Bob, > >>> > >>> I am using a ferrite rod antenna for the receiver. No outside antenna. > >>> > >>> Ray > >>> > >>> Original Message > >>> Subject: Re: [time-nuts] WWVB Dephaser Question > >>> From: Bob kb8tq > >>> Date: Thu, October 08, 2020 12:40 pm > >>> To: Discussion of precise time and frequency measurement > >>> > >>> > >>> Hi > >>> > >>> A lot depends on your antenna setup. You can also swamp out the > incoming > >>> WWVB signal……. > >>> > >>> Bob > >>> > >>>> On Oct 8, 2020, at 2:07 PM, < > >>> rcb...@atcelectronics.com> wrote: > >>>> > >>>> I have read several different articles where the WWVB phase shift is > >>>> eliminated by doubling the signal to 120 kHz. Several members of the > >>>> list have built these units. > >>>> > >>>> Assume I build a circuit to double the incoming signal and use a > >> schmit
Re: [time-nuts] WWVB/Anthorn Re: time-nuts Digest, Vol 195, Issue 27
Note that WWVB is 60kHz, not 65kHz. David N1HAC On 10/18/20 10:35 AM, paul swed wrote: Andre you can add layers of litz wire. You actually have litz wire? Thats hard to find these days. But it most likely will need to be more than a few layers. I would slip to small pieces of cardboard on both sides of the existing coil (glue in place) and then fill with the new wire. Check the L every 5 layers. May guess you need 10. But what you want to do can be done. Regards Paul WB8TSL On Sun, Oct 18, 2020 at 5:54 AM Andre wrote: Hi folks. Just a quick question, but I found a small AM/FM radio here (50p!) with a tiny ferrite rod. Wonder what it uses to set the frequency for AM range? Surely not a tuning diode like MV1404 as these are incredibly expen$ive. Was wondering about pulling the rod and modifying it for WWVB as my existing radio clock works and it would be a shame to mess that up. Should be easy enough as I have (somewhere!) a working LCR meter so can wind a suitable winding over the existing one if its too far off or simply add a couple of layers of Litz wire to approximate the required 65 kHz WWVB. I'd also need to locate a 65 kHz quartz crystal for the XT2 position. External antenna might be better here as it would be very weak indeed being from the USA but there's a couple of methods I can use to improve this like using an optical relay from multiple locations at equidistant points. thanks! Andre From: time-nuts on behalf of time-nuts-requ...@lists.febo.com Sent: 17 October 2020 23:02 Teference to match the DUT. But if you do want to mix both the REF and DUT channels, wouldn't it be better to use a single source to drive both mixers? John On 10/17/20 8:59 AM, Gerhard Hoffmann wrote: I'm trying to make a quick frequency extender for a timepod. MCL PSC2-1 power divider, 2* SRA-1 7 dBm ring mixer, 2 DIL 80 MHz-oscillators ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to https://nam12.safelinks.protection.outlook.com/?url=http%3A%2F%2Flists.febo.com%2Fmailman%2Flistinfo%2Ftime-nuts_lists.febo.comdata=04%7C01%7Cdavid.g.mcgaw%40dartmouth.edu%7Ccd7a228fe7184e57af7708d873889e59%7C995b093648d640e5a31ebf689ec9446f%7C0%7C0%7C637386377892631238%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000sdata=jhjMdQ2x%2BgnogUpucLefUkW7PMa%2FwCa6u41wqegWATY%3Dreserved=0 and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to https://nam12.safelinks.protection.outlook.com/?url=http%3A%2F%2Flists.febo.com%2Fmailman%2Flistinfo%2Ftime-nuts_lists.febo.comdata=04%7C01%7Cdavid.g.mcgaw%40dartmouth.edu%7Ccd7a228fe7184e57af7708d873889e59%7C995b093648d640e5a31ebf689ec9446f%7C0%7C0%7C637386377892631238%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000sdata=jhjMdQ2x%2BgnogUpucLefUkW7PMa%2FwCa6u41wqegWATY%3Dreserved=0 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 Dephaser Question
Have built whips and small loops and ferrite cores of various sizes. For me the best is the 10' by 10'. As mentioned earlier in the thread as measured on a dymec receiver. Other solutions during the day 10-30uv. Large loop 60-200. Night is just crazy up in the millivolt range. But not all of the time. It just depends on propagation. In New England the antenna does need the ability to null MSF out of England. A bit of a trade off. Last comment. Listening today and really seeing the noise floor upto 70-80 KHz climbing. Still tracking wwvb just fine but I fear far sooner then later that may not be the case. Regards Paul On Fri, Oct 9, 2020 at 5:42 PM Tim Shoppa wrote: > The NIST WWVB transmitter antenna is very massive and very well > documented: https://apps.dtic.mil/sti/pdfs/ADA299080.pdf > > For receive on VLF there is no reason to go so big. A short whip produces > plenty of atmospheric noise so there’s no purpose at going bigger. A loop > (including ferrite core loop) has a useful null to remove local noise > sources. A tuned loop with reasonable Q helps reject a lot of noise before > it reaches the first active stage. > > Tim N3QE > > > On Oct 9, 2020, at 5:14 PM, John C. Westmoreland, P.E. < > j...@westmorelandengineering.com> wrote: > > > > Bob, > > > > Thanks for the answer; but does anyone actually have a documented > > specification posted for one of these 'massive' WWVB 60kHz antennas > > someplace? > > > > Thanks. > > > > 73's, > > John > > AJ6BC > > > > > >> On Fri, Oct 9, 2020, 08:35 Bob kb8tq wrote: > >> > >> Hi > >> > >> At least to me, anything dimensioned in the 100’s of feet is “massive” > >> compared to > >> the rod antennas normally seen in WWVB use …. > >> > >> The other point being that if the antenna is some sort of large loop, > it’s > >> going to be > >> a good long ways away from the receiver. You get both a larger signal > >> voltage and better > >> isolation ….. > >> > >> Bob > >> > >>> On Oct 8, 2020, at 11:30 PM, John C. Westmoreland, P.E. < > >> j...@westmorelandengineering.com> wrote: > >>> > >>> Hello All, > >>> > >>> Are there any design details someplace regarding these massive > antennas? > >>> > >>> Thanks, > >>> John > >>> AJ6BC > >>> > >>> > >>>> On Thu, Oct 8, 2020, 19:27 paul swed wrote: > >>> > >>>> Hello to the group. > >>>> Ray as Bob mentions you are taking a 10s of uv signal to a logic level > >> of > >>>> maybe 4V. > >>>> If the loop is any place close to the divided down signal, it will > >>>> oscillate. It would take incredible shielding to protect the receiver. > >>>> Thats why you often see a solution that doubles to 120 KHz and > modifies > >> the > >>>> detectors to work at that frequency. That means hacking the radio > >>>> internally. Not fun. The other really annoy effect is that the > doubling > >>>> slips phace due to noise and propagation. So if charting suddenly you > >> get a > >>>> 180 degree flip. Thats messy. > >>>> The doubling solution can work. Search for carter and there are > several > >>>> others. > >>>> But having tested and used all of the alternates and lots more on the > >> east > >>>> coast decided they were too much trouble. You should see the box of > >> boards > >>>> I have chuckle. > >>>> For me I am very happy with the d-psk-r. Though in being above board I > >>>> designed version 1 and Rodger and I did version 2. Its solid and no > >> mods to > >>>> any receiver. Everything has always been released to the time-nuts > >> group. > >>>> As they say have fun. > >>>> Regards > >>>> Paul. > >>>> WB8TSL > >>>> > >>>> On Thu, Oct 8, 2020 at 5:39 PM wrote: > >>>> > >>>>> Bob, > >>>>> > >>>>> I am using a ferrite rod antenna for the receiver. No outside > antenna. > >>>>> > >>>>> Ray > >>>>> > >>>>> Original Message > >>>>> Subject: Re: [time-nuts] WWVB Dephaser Question > >>>>> From: Bob kb8tq > >>>>> Date: Thu, October 08, 2020 12:4
Re: [time-nuts] WWVB Dephaser Question
Hi Since you need a MCU to decode the data, you might as well get things in there sooner rather than later. There are a number of MCU’s out there that have fast enough ADC’s to do the job. They do have limited dynamic range. You can go to one of the 24 bit converters and have a ton of dynamic range. It’s all up to you. Once it’s into the MCU, it’s just code :). Depending on how much cpu horsepower you have (and how much code you want to write) you can go more or less crazy …. PHK has some interesting tidbits on his web site. http://phk.freebsd.dk/AducLoran/AducLoran-0.0.pdf <http://phk.freebsd.dk/AducLoran/AducLoran-0.0.pdf> Bob > On Oct 9, 2020, at 1:38 PM, rcb...@atcelectronics.com wrote: > > Paul, Bob, > > I am not using any commercial receiver. I am building everything from > scratch. The RF front end starts with a ferrite rod antenna feeding a > differential first op amp followed by 5 stages of op amp filtering and > amplification. When the last stage is fed to my spectrum analyzer > (through attenuators) the WWVB signal is clearly visible. I'm now trying > to figure out how to detect the phase shift so I can get the time data > for my CPU to process and send to a display. > > I already have a GPS based clock that I built so I thought the WWVB > phase clock would be an interesting project. > > Ray > > ---- Original Message > Subject: Re: [time-nuts] WWVB Dephaser Question > From: Bob kb8tq > Date: Fri, October 09, 2020 7:35 am > To: Discussion of precise time and frequency measurement > > > Hi > > At least to me, anything dimensioned in the 100’s of feet is > “massive” compared to > the rod antennas normally seen in WWVB use …. > > The other point being that if the antenna is some sort of large loop, > it’s going to be > a good long ways away from the receiver. You get both a larger signal > voltage and better > isolation ….. > > Bob > >> On Oct 8, 2020, at 11:30 PM, John C. Westmoreland, P.E. >> wrote: >> >> Hello All, >> >> Are there any design details someplace regarding these massive antennas? >> >> Thanks, >> John >> AJ6BC >> >> >> On Thu, Oct 8, 2020, 19:27 paul swed wrote: >> >>> Hello to the group. >>> Ray as Bob mentions you are taking a 10s of uv signal to a logic level of >>> maybe 4V. >>> If the loop is any place close to the divided down signal, it will >>> oscillate. It would take incredible shielding to protect the receiver. >>> Thats why you often see a solution that doubles to 120 KHz and modifies the >>> detectors to work at that frequency. That means hacking the radio >>> internally. Not fun. The other really annoy effect is that the doubling >>> slips phace due to noise and propagation. So if charting suddenly you get a >>> 180 degree flip. Thats messy. >>> The doubling solution can work. Search for carter and there are several >>> others. >>> But having tested and used all of the alternates and lots more on the east >>> coast decided they were too much trouble. You should see the box of boards >>> I have chuckle. >>> For me I am very happy with the d-psk-r. Though in being above board I >>> designed version 1 and Rodger and I did version 2. Its solid and no mods to >>> any receiver. Everything has always been released to the time-nuts group. >>> As they say have fun. >>> Regards >>> Paul. >>> WB8TSL >>> >>> On Thu, Oct 8, 2020 at 5:39 PM wrote: >>> >>>> Bob, >>>> >>>> I am using a ferrite rod antenna for the receiver. No outside antenna. >>>> >>>> Ray >>>> >>>> Original Message >>>> Subject: Re: [time-nuts] WWVB Dephaser Question >>>> From: Bob kb8tq >>>> Date: Thu, October 08, 2020 12:40 pm >>>> To: Discussion of precise time and frequency measurement >>>> >>>> >>>> Hi >>>> >>>> A lot depends on your antenna setup. You can also swamp out the incoming >>>> WWVB signal……. >>>> >>>> Bob >>>> >>>>> On Oct 8, 2020, at 2:07 PM, < >>>> rcb...@atcelectronics.com> wrote: >>>>> >>>>> I have read several different articles where the WWVB phase shift is >>>>> eliminated by doubling the signal to 120 kHz. Several members of the >>>>> list have built these units. >>>>> >>>>> Assume I build a circuit to double the incoming signal and use a
Re: [time-nuts] WWVB Dephaser Question
For my little WWVB project I used the table saw to cut off the upper 3 inches of a 5 gal bucket from Lowes (having removed the handle first). Then I wrapped that with about 30 turns of enameled wire from an old TV flyback transformer. I then measured the inductance and added the required capacitance to tune it to 60 kHz. I am doing direct sampling with a teensyduino and sound card. I have not tackled the phase decoding, which would be superior. https://github.com/chris-elfpen/Teensy4WWVBsdr On 10/9/20 7:04 PM, John C. Westmoreland, P.E. wrote: Paul, Thanks for that detailed explanation. I've done something similar for MARS but of course higher frequency and that was transmit also. I've seen the site of something similar but I think that was a 3' diameter design; and I've looked at some of the Symmetricom schematics I've been able to find but have yet to find a schematic of one of the Symmetricom receive antennas. I was hoping to find the one they had for outdoor pole mount. It's mentioned in a lot of their documents and even some pics but no schematic details or BOM for that I've been able to find. Thanks to Tim also for the response and have a good weekend! 73's, John AJ6BC On Fri, Oct 9, 2020, 15:24 paul swed wrote: John I don't think so as not sure how many have built a large antenna. Certainly any of the old wwvb receivers have details and thats pretty much what most people copy. Essentially a 3 foot copper loop with numbers of turns of wire connected together. Like 25 pair telco cable connected end to end. A large capacitor is then put across the loop to resonate it at 60 KHz. Then the preamp. Some use a FET transistor followed by a line driver transistor. Power is sent over the coax so a blocking cap and inductor. Really big is 10' by 10' using shielded 36 wire ribbon cable. ( did not use all 36 conductors it was to much L but 800 ft worth. The shield acts like the copper pipe and it must be broken so that it does not look like a shorted loop. Add the cap and preamp. In this case I built a 2 transistor NPN 2n3904 preamp. On the large antenna I use a 2 X 6 post 4ft in the ground with cement. A mast above that to support the antenna and to allow it to be turned a bit to null MSF. Thats it no real magic. Its been operational for 7 years with an occasional transistor replacement. Also coax, darn woodpeckers! Regards Paul WB8TSL On Fri, Oct 9, 2020 at 5:14 PM John C. Westmoreland, P.E. < j...@westmorelandengineering.com> wrote: Bob, Thanks for the answer; but does anyone actually have a documented specification posted for one of these 'massive' WWVB 60kHz antennas someplace? Thanks. 73's, John AJ6BC On Fri, Oct 9, 2020, 08:35 Bob kb8tq wrote: Hi At least to me, anything dimensioned in the 100’s of feet is “massive” compared to the rod antennas normally seen in WWVB use …. The other point being that if the antenna is some sort of large loop, it’s going to be a good long ways away from the receiver. You get both a larger signal voltage and better isolation ….. Bob On Oct 8, 2020, at 11:30 PM, John C. Westmoreland, P.E. < j...@westmorelandengineering.com> wrote: Hello All, Are there any design details someplace regarding these massive antennas? Thanks, John AJ6BC On Thu, Oct 8, 2020, 19:27 paul swed wrote: Hello to the group. Ray as Bob mentions you are taking a 10s of uv signal to a logic level of maybe 4V. If the loop is any place close to the divided down signal, it will oscillate. It would take incredible shielding to protect the receiver. Thats why you often see a solution that doubles to 120 KHz and modifies the detectors to work at that frequency. That means hacking the radio internally. Not fun. The other really annoy effect is that the doubling slips phace due to noise and propagation. So if charting suddenly you get a 180 degree flip. Thats messy. The doubling solution can work. Search for carter and there are several others. But having tested and used all of the alternates and lots more on the east coast decided they were too much trouble. You should see the box of boards I have chuckle. For me I am very happy with the d-psk-r. Though in being above board I designed version 1 and Rodger and I did version 2. Its solid and no mods to any receiver. Everything has always been released to the time-nuts group. As they say have fun. Regards Paul. WB8TSL On Thu, Oct 8, 2020 at 5:39 PM wrote: Bob, I am using a ferrite rod antenna for the receiver. No outside antenna. Ray Original Message Subject: Re: [time-nuts] WWVB Dephaser Question From: Bob kb8tq Date: Thu, October 08, 2020 12:40 pm To: Discussion of precise time and frequency measurement Hi A lot depends on your antenna setup. You can also swamp out the incoming WWVB signal……. Bob On Oct 8, 2020, at 2:07 PM, < rcb...@atcelectronics.com> wrote: I have read several different articles where the WWVB phase shift is elim
Re: [time-nuts] WWVB SDR discussion
Mike, I've used that seller a lot; no worries. They have 800+ items for sale, mostly clock and weather products by La Crosse Technology [1]. It looks like this eBay seller is their online retail store, as well as an outlet for their overstock and refurbished items: https://www.ebay.com/itm/274056463528 Seller: greatbigoutlet Item location: La Crosse, Wisconsin, United States Condition: Manufacturer refurbished One of the complaints that I had about the La Crosse 404-1235UA-SS UltrAtomic clock was that several of the ones I bought had misaligned hands [2]. If you're into Lavet stepper motor watch movements using optical feedback it's something you can fix yourself. The other solution is to return it to the factory. It wouldn't surprise me that La Crosse has a pile of these refurbished clocks for sale. Or maybe 1235UA just never sold well; or maybe there's a new model coming; who knows. And, yes, this is a deal for $35. They are so much better than older WWVB clocks. AFAIK it is still the only LF radio clock that uses the new eWWVB PM format. The smaller clocks and watches all use the legacy WWVB AM format. /tvb [1] https://www.lacrossetechnology.com/ [2] http://leapsecond.com/pages/ultratomic/ On 8/20/2020 8:00 PM, Mike Feher wrote: Hi Don - I got two of them on eBay. I got these 274056463528 . They were only $35 each with free shipping, a bargain in my opinion. Of course you can find smaller diameter ones as well. 73 - Mike Mike B. Feher, N4FS 89 Arnold Blvd. Howell NJ 07731 848-245-9115 -Original Message- From: time-nuts On Behalf Of DON MURRAY via time-nuts Sent: Thursday, August 20, 2020 8:41 PM To: time-nuts@lists.febo.com Cc: DON MURRAY Subject: Re: [time-nuts] WWVB SDR discussion Mike... Which model did you order? 73 Don W4WJ On Thursday, August 20, 2020 Mike Feher wrote: I just purchased 2 of those La Crosse 14" clocks and was totally amazed. I live on the Jersey shore on one acre surrounded by trees and about 8 miles from the ocean. After I placed batteries in the clock, it went through its initially routine which was neat in itself, and about an hour or less later the motors purred again and it went to the exact time and continues to do so. This was on the first floor of my Colonial in my office next to the computer and all sorts of other digital and switching PS noise and only about a foot off the floor. My old Junghans Mega 1000 could never do that. I have to take it upstairs with me and place it by the front (South facing) window of the master bedroom and sometime during the night it acquires and corrects if need be. Regardless, I still like my Junghans, but this new waveform is amazing. Thanks for mentioning it. Regards - Mike Mike B. Feher, N4FS 89 Arnold Blvd. Howell NJ 07731 848-245-9115 ___ 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 SDR discussion
Hi Detlef, On 11-Aug-20 3:46 AM, Detlef Schuecker via time-nuts wrote: > you do not necessarily need a variable ( physical ) oscillator. You mix > the signal down in the digital domain. A 'digital local oscilator' is a > mere complex value, which is rotated and the power is adjusted: My proposed block diagram does actually have a digital LO, only mine is 1, 0, -1, 0... (in-phase) and 0, -1, 0, 1... (quadrature). You could of course use an variable-frequency NCO, but I need a physical oscillator in any case to clock the MCU. I am also thinking in terms of a WWVB-DO where I want a stable local reference to steer. (Although in fairness, for WWVB I think you probably want stability over the diurnal propagation variation, and my crappy OCXO has no chance at that.) >> part, unfortunately. My tuned loop seems still too broadband, even >> after a couple more poles of op-amp filter. I have a bunch of 60-kHz >> tuning-fork crystals and wanted to try a crystal filter like the "pros" > Good point. > Firstly I tried a tuned resonant LC circuit with a BF245 preamplifier to > keep a high Q. Besides having minimal analog design experience, I think what is confusing me is these crystals have a really high impedance far away from their parallel resonance. Even at series resonance the motional resistance is in the 10s of kohms, IIRC. So I'm not exactly sure how to deploy one in place of an LC tank circuit, e.g. in a collector or drain circuit. > Secondly an accurate ADC is an option. With 24Bit you get more than 100dB > dynamic range, so you dont care about a 60dB stronger nearby interferer. Fancier ADC shouldn't make any difference. Even though the STM32L4 ADC has an SNR of (IIRC) ~ 69 dB, you can sample at several MHz. After downsampling to something like 100 Hz (post LO), the SNR is well over 100 dB, which should be plenty. (Of course, this presupposes that there are not strong interferers or SMPS noise spurs, etc. within a 100-Hz BW centered on 60 kHz. But if there are, a fancy ADC wouldn't help you anyway. The main thing is to make sure the interference isn't causing any clipping or nonlinearity before you sample.) I should note that my big tuned air loop and preamp, which is modeled after Joe Magliacane's, may be adequate even though I can't see WWVB on the oscilloscope. I was hoping to build confidence there before hooking it up to the MCU and doing SDR stuff. I also want a small loopstick version of this so I can embed it in my own nixie wall clock, hence the interest in crystal filters, etc. Mark ___ 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 SDR discussion
On Tuesday, August 11, 2020, 07:14:12 PM EDT, Bob kb8tq wrote: > The problem with the crystal is that it has a temperature coefficient. As a > narrow band filter, it will have a *lot* of delay. Crystal resonance moves > (with temperature) and the delay changes. I agree. The crystal needs to be ovenized. ;-) That very concern led me in my design to derive nearly all my receiver selectivity at baseband (DC) using op-amps, forgo any crystal filters, and keep the Q of the loop antenna low. 73.000 de John, KD2BD ___ 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 Backing up a bit ….. The WWVB modulation is *very* predictable. Once you have lock, you can guess just about every phase reversal you will see. If you have an “approximate lock” ( = a time pre-load that is within a few seconds) you can guess a lot of them. (There were a few aux data bits in the stream last time I looked). In the case of the pre-load, you still need to get your local stream lined up with reality. In all cases, the ionosphere will move things enough that some modest amount of servo would be needed. The point of this being that you *could* pre-flip the data before it went into a buffer. That way the buffer integration time constant could be quite long. The main penalty is a bit of work getting it all locked up in the first place. If this is a precision timing receiver (as opposed to a wrist watch) that may not be a problem. Bob > On Jul 30, 2020, at 11:45 PM, rcb...@atcelectronics.com wrote: > > Paul, > > I wasn't talking about putting the d-psk-r software on the Blue Pill > board. The d-psk-r software will be on the Arduino board. > > What I was thinking of doing was putting a single NEMA message on the > Blue Pill board. Then connect the UART transmit line to the Arduino in > place of the GPS UART line. That way I could send the same NEMA message > without having it change every minute. I would count 60 (or maybe 62) > pps coming from the GPS and I would know the Arduino was ready for the > next NEMA message. > > Initially I will use the GPS UART transmit line to confirm the > Arduino/GPS combo works. Then play with sending my own NEMA GPRMC > message from the Blue Pill board. > > > It appears your software simply reads the TX buffer of the GPS until it > is empty once per minute and then proceeds to parse the NEMA time/date > information out one bit per second. However, the La Crosse Ultratomic > clock would not work with this data stream since you are stripping the > phase reversals out. Is that correct? > > I want to extract the time information only. So I would feed the 60 kHz > sine wave into the preamp wire on the flipper board. Is that correct? > > Ray, > AB7HE > > Original Message > Subject: Re: [time-nuts] WWVB PM Time Questions > From: paul swed > Date: Thu, July 30, 2020 5:14 pm > To: Discussion of precise time and frequency measurement > > > Ray > Are you speaking to the d-psk-r software? Its quite a bit more involved > than what you mentioned. Its in the coding sequence. But could it be put > on > a bluepill absolutely. Its worked on all of the arduinos we have tried. > The > other thing is that by feeding a 60 KHz CW signal into the d-psk-r > modulator/flipper it turns the signal into a wwvb bpsk signal. No AM > modulation. But for bench testing its a noise free signal. > But I am interested in the approach you are trying to develop that I > guess > might be a SDR solution. Good luck looking forward to your success. > Regards > Paul. > > ___ > 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
Ray Yes you have it correct. The flipper is bidirectional. It either adds flips or removes them. It does read the nema second per minute in the 59th second. Then depends on the 1 pps for an accurate phase flip. The flip is 100 ms into the second and by propagation delay to the east 5-7ms. Though the reality is if the flips not exact the phase tracking receivers work just fine. But beyond the simple reading of the nema sentence its the magical conversion to the new wwvb message format thats quite difficult. Then they turned on teh slow code and Rodger and I worked that issue. That actually took some months to resolve the fast and slow code integration. So as a transmitter put the software on an arduino or bluepill. Since you are just doing work locally the nema sentence can be repeated over and over. Regards Paul WB8TSL On Fri, Jul 31, 2020 at 12:01 AM wrote: > Paul, > > I wasn't talking about putting the d-psk-r software on the Blue Pill > board. The d-psk-r software will be on the Arduino board. > > What I was thinking of doing was putting a single NEMA message on the > Blue Pill board. Then connect the UART transmit line to the Arduino in > place of the GPS UART line. That way I could send the same NEMA message > without having it change every minute. I would count 60 (or maybe 62) > pps coming from the GPS and I would know the Arduino was ready for the > next NEMA message. > > Initially I will use the GPS UART transmit line to confirm the > Arduino/GPS combo works. Then play with sending my own NEMA GPRMC > message from the Blue Pill board. > > > It appears your software simply reads the TX buffer of the GPS until it > is empty once per minute and then proceeds to parse the NEMA time/date > information out one bit per second. However, the La Crosse Ultratomic > clock would not work with this data stream since you are stripping the > phase reversals out. Is that correct? > > I want to extract the time information only. So I would feed the 60 kHz > sine wave into the preamp wire on the flipper board. Is that correct? > > Ray, > AB7HE > > Original Message > Subject: Re: [time-nuts] WWVB PM Time Questions > From: paul swed > Date: Thu, July 30, 2020 5:14 pm > To: Discussion of precise time and frequency measurement > > > Ray > Are you speaking to the d-psk-r software? Its quite a bit more involved > than what you mentioned. Its in the coding sequence. But could it be put > on > a bluepill absolutely. Its worked on all of the arduinos we have tried. > The > other thing is that by feeding a 60 KHz CW signal into the d-psk-r > modulator/flipper it turns the signal into a wwvb bpsk signal. No AM > modulation. But for bench testing its a noise free signal. > But I am interested in the approach you are trying to develop that I > guess > might be a SDR solution. Good luck looking forward to your success. > Regards > Paul. > > ___ > 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
Bob kb8tq writes: > It also *very* much depends on the stability of your local reference and the > stability of the ionosphere. Unless both are 'pretty darn good' a hundred > second > integration is utter nonsense This is why Loran-C was so superior to any and all CW based modulations. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@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 coloring is from matplotlib. Sometimes I forget what's what. I'm
really not using pandas for much here. Most of the code in plotting a
minute of data is in making it look fancy.
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.ticker as tkr
import matplotlib.mlab as mlab
import pandas as pd
sFile = 'out.txt' # in current directory, or give full path
df = pd.read_csv(sFile, header=None,
names=['sample_time', 'amplitude', 'phase'],
sep=' ', index_col=0)
phase_deg = np.rad2deg(df_phase.phase) # phase_deg is a series
plt.subplots(figsize=(15, 3))
ax = plt.subplot(1,1,1)
plt.title('WWVB Phase5 - 70 sec')
ax.plot(phase_deg.clip(-120, 120), lw=0.4)
plt.xlim(6, 71)
plt.ylim(-150, 150)
ax.fill_between(phase_deg.index,
0,
phase_deg.clip(-120, 120), where=phase_deg>=0,
color='green', alpha=0.15)
ax.fill_between(phase_deg.index,
0,
phase_deg.clip(-120, 120), where=phase_deg<0,
color='red', alpha=0.15)
ax.xaxis.set_major_locator(tkr.MaxNLocator(8))
ax.xaxis.set_minor_locator(tkr.AutoMinorLocator(n=10))
ax.grid(b=True, which='major', c='g', linestyle='-', linewidth=0.7)
ax.grid(b=True, which='minor', c='g', linestyle='-', linewidth=0.2)
sSave = 'wwvb_phase_5_70.png'
plt.savefig(sSave, bbox_inches='tight', transparent=False, dpi=100)
Rob
On Fri, Jul 31, 2020 at 1:15 PM jimlux wrote:
>
> On 7/31/20 11:25 AM, Scud West wrote:
> > Back in December 2018 there was a WWVB thread.
> >
> > From Poul-Henning's post on 2018-12-05 quoting John N8UR:
> >
> > "While everyone's been talking :-) , I recorded some WWVB IQ data for
> > folks to play with. You can download it from
> >
> > http://febo.com/pages/wwvb/
> >
> > The receiver ran at 48 ksps and was centered on 80 kHz (to allow a 20
> > kHz IF to move away from 0 Hz crud). The data was taken in early
> > afternoon in Dayton, Ohio. WWVB was easily visible in an FFT."
> >
> >
> > I ran the python code posted by Poul-Henning with the WWVB IQ data.
> > The resulting file 'out.txt' has columns for sample time, amplitude,
> > and phase. It was used for the plots below. There is about 10
> > minutes of data.
> >
> > initial data:
> > n8ur_rx_center=0.08MHz_rate=48ksps_start=2018.12.05.13.57.54.bin
> > (236 MB)
> > plotted data: out.txt (2.4 MB, 61,000 datapoints)
> >
> > I hadn't looked at phase data before, and it took a while to make any
> > sense of it. It's surprising how well the bit per second data came
> > through, compared to amplitude modulation. Different filtering will
> > likely improve the AM performance, but the phase plot looked good now,
> > so here it is.
> >
> > The first graph shows the +90 degree phase shift (top line) and -90
> > (bottom line). The SDR clock appears relatively stable at first, but
> > drifts lower in frequency at a fairly steady rate until about 550
> > seconds, when it flattens out again. Overall a bit over 180 degrees
> > more than expected. A half cycle at 60 kHz, or about 8.3e-06 drift in
> > 10 minutes. The unpleasantness at about 470 seconds is reflected in
> > the 10 minute plot during minute 7 (3 lines down from the top). I
> > removed the 'drift' in a crude manner, and it's a wonder it worked as
> > well as it did.
> >
> > The middle two graphs are the same data at different time scales. I'm
> > not sure if the short term phase variation has any meaning, or if it's
> > 'just noise' at this level. The WWVB phase change actually takes
> > place 0.1 seconds after the start of the second, but it fit just right
> > for display as is. The real minute begins at second 6, and this is
> > adjustment is made in the 10 minute waterfall plot. The first few
> > seconds of data are at the bottom left corner.
> >
> > Green denotes binary 1, phase shift +90 degrees.
> > Red is binary 0, phase shift -90 degrees.
> >
> > A simplified description of WWVB phase-modulated time code:
> >
> > seconds 0 - 12 fixed sync 0, 0, 1, 1, 1, 0, 1, 1, 0, 1, 0, 0, 0
> > seconds 13 - 18 time parity (ECC)
> > seconds 19 - 46 binary minute of century
> > seconds 47 - 58 DST and leap sec
> > second 59 fixed sync 0
> >
> > these seconds are notable here:
> >
> > 43, 44, 45, 46 contain changing binary minutes 3, 2, 1, 0
> > 19 a copy of binary minute 0
> > 29, 39 Reserved, but also a copy of binary minute 0 in this sample.
> >
> >
> > I'm using python, numpy, matplotlib, and Pandas. It all runs pretty
> > quick on my machine, only a fe
Re: [time-nuts] WWVB PM Time Questions
From a signal processing point of view this problem interests me, so I wanted to float an idea. If I read the WWVB document correctly, the phase shifts are always going to be +/-180° out of phase, but still the exact same frequency. It would stand to reason that if one wanted to detect this - one would want to start by comparing two signals to the incoming clock, one normal and one inverted (essentially, a differential signal). Once the received RF clock frequency is locked in phase with the local oscillator, adding the incoming signal to both normal and inverted would be illuminating to see which phase is used by simple RMS math. 180° out of phase added to the incoming signal would be zero ((+1) + (-1) = 0, while ((+1) + (+1) = 2 - then do your absolute RMS window over 1.5 cycles (three peaks). Note that the out-of-phase signal would be zero when correctly locked but would be greater than zero (absolute) if not locked. These two analog outputs for each, can then have a hysteresis applied to them to produce a logical output by feeding them into a comparator op-amp - the phase tuning can then be steered from sampling the valid output phase based on the binary selection (additional windowing two gate when phase shifts are possible can steer the hysteresis values for noise robustness). For example, bit transitions may only occur on bit edge transitions - so detecting a phase shift and counting the center- to center of that phase shift should help reject mid-bit-period errors. You'd need to know this window anyway to know when to clock in a phase bit state (middle 1/3rd or middle 3/5ths). Should be doable in hardware with some counters/digital-comparators... -Tim On Thu, Jul 30, 2020 at 9:00 AM wrote: > > Date: Wed, 29 Jul 2020 20:33:41 -0700 > From: > To: "Discussion of precise time and frequency measurement" > > Subject: Re: [time-nuts] WWVB PM Time Questions > Message-ID: > < > 20200729203341.db13e9c5ce513c85d5e788cef9f0c738.7489e885d3@email06.godaddy.com > > > > Content-Type: text/plain; charset="utf-8" > > Paul, > "The new de-psk-r I built has no raw wwvb outputs." What do you mean by > raw? > > I have been thinking about how the phase shift could be detected in > software instead of hardware. Could something like this maybe work: > > If a micro is able to detect the zero crossing of a sine wave it should > be able to determine if the phase shifts. When a new second starts > (which is easy to determine), delay for 300 msec and then watch for the > next zero crossing. Store the time at that point. Then wait 1000 msec > which would put you at the same point in the next second. Wait for the > next zero crossing and determine the time between that crossing and the > first crossing. You can compute the phase difference based on the time > difference. If the phase difference is between 100 degrees and 180 > degrees, you know a phase shift has taken place. The reason for using > 100 as the low number is in case the zero crossing on one sine wave was > at the leading edge and it was on the trailing edge of the other one. > > You would want to use the output of the PLL to perform those operations > since it is local and not subject to ionospheric interference or delays. > A 100 MHz STM32 should be able to easily handle the calculations in a > couple of microseconds. > > > 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] WWVB PM Time Questions
Ray, > How do the La Crosse distributors sell the ULTRATOMIC clock for $35-$40. That's a bit lower than a few years ago when it first came out. > Building a million clocks would get the cost down, In this case, likely thousands not millions. The market for WWVB clocks took a hit in the 21st century when GPS, the internet, WiFi, and smart phones took over. > I'm sure there are a lot of transistors in their IC to handle all the phase tracking and time decoding. Read about the ES100 chip inside the UltrAtomic clock. Also note it's not a "phase tracking" receiver per se. It's purpose is to get UTC via the subcode, not to track NIST / WWVB carrier phase. Technical documents can be found here: http://everset-tech.com/ > It is obvious they don't have a vcTCXO in the clock Correct. For more details of the crystal(s) and typical performance see: http://leapsecond.com/pages/ultratomic/ > A lot of reviews say their clocks based on the AM modulation method > would not sync but the phase modulation ones always work. Agreed. The amount of AM noise near 60 kHz is getting worse by the year so, at least in my experience, the eWWVB phase modulation decoders work much better than the legacy WWVB amplitude decoders. /tvb On 7/30/2020 12:01 PM, rcb...@atcelectronics.com wrote: So the $64 million dollar question is this. How do the La Crosse distributors sell the ULTRATOMIC clock for $35-$40. That means La Crosse's manufacturing cost is probably around $15-$20. Building a million clocks would get the cost down, but still. I'm sure there are a lot of transistors in their IC to handle all the phase tracking and time decoding. It is obvious they don't have a vcTCXO in the clock so they must be doing everything in software. Or maybe the IC is a combination micro and FPGA. Any ideas how they would approach that? If you read the online reviews of the clock they are about 99% positive. A lot of reviews say their clocks based on the AM modulation method would not sync but the phase modulation ones always work. Ray, AB7HE Original Message ---- Subject: Re: [time-nuts] WWVB PM Time Questions From: paul swed Date: Thu, July 30, 2020 10:39 am To: Discussion of precise time and frequency measurement Cc: rcb...@atcelectronics.com Well John perhaps there is some interest in your receiver. I see the vcTCXO is down by 5 devices from yesterday. Make that 6 now. For anyone else usps is cheapest at $4.99. Regards Paul On Thu, Jul 30, 2020 at 10:29 AM paul swed wrote: Hello to the group. Poul has done some very fine work and you can learn a lot from him. But several comments that will help. Its easy to create all kinds of solutions that look for phase shifts. I spent quite a bit of time doing that. But the nasty reality is without accounting for the noise, signal fades, and delay shifts they generally fail. Or work for short periods of times. Simplistically if you have a 1 second image of the incoming signal its easy to see the phase shift. With respect to zero crossings it works really poorly. Thats why on Loran C they were very clear the slice point was as I recall 30% up the envelope. Humor on the d-psk-r. The new unit does not have an output that contains the phase shifts of wwvb. The units intention is to remove all phase shifts so that all old style phase tracking receivers and clocks work. They all do. Have 7 of them. So to experiment with Johns fine KB2DB receiver I need the raw phase flipping wwvb signal. I have built his receiver and now that there is an answer to the TCXO issue I need a raw feed. Chuckle. When I built the new unit I really debated adding that BNC. Hindsight is always really clear. Best regards Paul WB8TSL On Thu, Jul 30, 2020 at 4:48 AM Poul-Henning Kamp wrote: rcb...@atcelectronics.com writes: > Paul, > "The new de-psk-r I built has no raw wwvb outputs." What do you mean by > raw? > > I have been thinking about how the phase shift could be detected in > software instead of hardware. Could something like this maybe work: Back when I played with VLF, I did this on DCF77/Rugby etc. In my case I used a 12 bit 1MSPS ADC, and (exponentially) averaged the RF signal into per-station circular buffer, this is very cheap and fast to do in an interrupt handler. In your main code you can demodulate that buffer to DC by multiplying and summing with precomputed sin tables. That gives you baseband I & Q from which you can trivially calculate phase and amplitude. You can make the buffer as short or long as you want, I did the trivial thing and made it a full second long: http://phk.freebsd.dk/loran-c/CW/ The trick to that is that you can recover many stations from the same circular buffer, by using different sin tables. All the above plots came out of the same single 1sec buffer snapshot. This obviously works for any buffe
Re: [time-nuts] WWVB teensy BPSK early experiments
Hello Graham and Fellow Time Nuts, I did what Paul had mentioned as well - and that appeared to clear up the immediate screen issues but I will insert a termination resistor as well as Graham has suggested. I looked on the PJRC forum as well - and it appears there has been a lot of discussion and development regarding the enhancement of the performance of these TFT displays - also - there's a beta version of the arduino libraries - Teensyduino 1.54 Beta #4 - https://forum.pjrc.com/threads/64303-Teensyduino-1-54-Beta-4 - take a look at that for those that are experimenting with this platform. As far as my current setup - in the wee hours today - the WWVB signal was coming in very strong - my HPSDR rig using the Clock tool from Multipsk was decoding every minute - the Clock programs' PLL was solidly locked. I noticed for the Teensy4WWVBsdr code it appeared to be in sync with WWVB - it was decoding either a minute or the hour apparently correctly - but it was shifted - meaning say for: 2:38:00 AM it decoded 2 as the minute - which was incorrect but correct for another time position or, for the hour it would say 8 as hour. This makes me think obviously for some reason the positions are being shifted in an otherwise somewhat successful decode attempt. I am using the Teensy 4.1 - I need to check all of the libs to make sure nothing incompatible is possibly taking place. I've been informed also the antenna from Stormwise is on the way. Thanks again Graham - KE9H - for helping out on this. 73's, John AJ6BC On Sun, Nov 8, 2020 at 8:02 AM Graham / KE9H wrote: > John W: > > Regarding your Teensy WWVB receiver display issues. > The Teensy does not have a source termination resistor on the SPI clock. > Add a 50 Ohm resistor (value not critical, anything from 33 to 75 will > work) in series with the SPI Clock signal, as physically close to the > Teensy as practical. > This totally cleared up all of my display issues. > https://www.analog.com/media/cn/training-seminars/tutorials/MT-097.pdf > Source termination resistors provide a source resistance to absorb the > reflection of fast edges off the slave device input, reducing all the > bouncing and wiggles on the rising and falling edges of signals, > particularly important/beneficial on clock signals. > > --- Graham > > == > > > On Wed, Nov 4, 2020 at 10:55 AM John C. Westmoreland, P.E. < > j...@westmorelandengineering.com> wrote: > > > Paul/Chris, > > > > Also - in addition to the white screen, I get this sometimes after > running > > for a while - have you guys seen this? > > > > > > > https://user-images.githubusercontent.com/2308903/98118247-cd4c7b00-1e5f-11eb-8510-aa1ed0beba52.jpg > > > > 73's, > > John > > AJ6BC > > > > > > 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] Re: Time Signal Transmitter (low power)
Got a mobile phone with a speaker? There are "emulator" software apps which generate the appropriate time signals (e.g. 60 KHz WWVB) as harmonics of sounds emitted through mobile phone speakers: iPhone/iPad: ihttps://apps.apple.com/us/app/clock-wave/id1073576068 Android: https://play.google.com/store/apps/details?id=jp.houryo.wwvbemulator=en_US Nota Bene: this is not something that will work within a 20m radius. Think more along the lines of 0.25m or less. Erik Fair ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: CHU transmitters off air for a while
On Tue, May 31, 2022 at 1:30 PM Dave via time-nuts wrote: > > Excuse my ignorance but what is CHU ??? Is it like MSF ?? Yes and no. More akin to WWV in that it transmits on HF (MSF is only 60 kHz like WWVB, yes?) https://nrc.canada.ca/en/certifications-evaluations-standards/canadas-official-time/nrc-shortwave-station-broadcasts-chu -- Peter Laws | N5UWY | plaws plaws net | Travel by Train! ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-le...@lists.febo.com
Re: [time-nuts] WWVB Signal Generator
> Wayne very good progress. You can actually feed the loop coild that exists > with the cap it should resonate. > Thats my plan at least. Thanks, Paul. Actually, after running a few more tests, the BALDR seems to now set quite reliably with the wire just wrapped around the ferrite rod as long as the clock is with 2 inches of the ferrite rod. I'm using the WWVB receiver module in another experiment, so I don't want to risk damaging the module by applying a 5 volt PVM signal to the coil. But, I have a another WWVB receiver module on order so, once it arrives, I'll try out your suggestion. I've also ordered some ferrite rods in order try my hand at rolling a 60 kHz antenna from scratch, so that will be another adventure. Wayne On Thu, Aug 30, 2018 at 8:04 PM paul swed wrote: > Wayne very good progress. You can actually feed the loop coild that exists > with the cap it should resonate. > Thats my plan at least. > Regards > Paul > WB8TSL > > On Thu, Aug 30, 2018 at 9:44 PM, Wayne Holder > wrote: > > > I've had some luck improving things with my ATTiny85-based WWVB Simulator > > design by replacing the crappy, 8 MHz internal oscillator with an 8 MHz > > crystal and removing the tweaked timer values I had previously used. In > > addition, based on a suggestion from Paul Swed, I tried looping the > antenna > > wire a few times around the ferrite rod of a WWVB receiver module I > > happened to have lying around and this also greatly improved things (see > > photo on web page at > > https://sites.google.com/site/wayneholder/controlling-time). In fact, > > with > > the ferrite rod in place, the BALDR clock now syncs even when completely > > disconnected from being grounded to the ATTiny85 and the scope. > > > > I've updated my web page, and the source code at the bottom of the page, > > accordingly. BTW, the SYNC output is now moved to pin 7 and the PPS > output > > is currently disabled in the code. In addition, I've added some > additional > > info on my web page about how to compile and download the program to an > > ATTiny85 using ATTinyCore by Spence Konde. > > > > I've ordered a 15.36 MHz crystal to try, as that should let the ATTiny85 > > generate a true, 60,000 Hz output but, so far, the 8 MHz crystal has > helped > > improve things quite a bit. In addition, I plan to do more tests on > > different types of antennas in order to see if I can make things even > more > > reliable and stable. > > > > I still plan on reworking the code so it can also run on a 328-based > > Arduino board but, currently, the Arduino IDE has no easy way to work > with > > boards that don't use a standard, 16 MHz crystal, as this frequency is > used > > by the serial port and, in turn, by the boot loader, so altering it can > > break the ability to upload code. This has actually caused some issues > for > > some of my other projects, so I'm investigating how this issue might be > > handled. > > > > Also, if anyone is interested in trying out other modulation schemes, I > can > > easily add a compile option t the code that will let it output a binary > > low/high modulation signal instead of the PWM signal. > > > > Wayne > > > > On Thu, Aug 30, 2018 at 8:53 AM paul swed wrote: > > > > > Wayne as I work through the chronverter I do know the good phase > tracking > > > clocks really demand on frequency behavior. As I measured its +/- .6 Hz > > at > > > 60 KHz. I believe the cheapy wall clocks are a bit wider, but not sure > as > > > they are hard to actually measure. They do use a small tuning fork > > crystal > > > and from experience these are sharp. When I experimented with them they > > > were maybe 5 Hz. Indeed the Chinese website had 25 X 60 KHz crystals > for > > > maybe $2. > > > With respect to the antenna. My thinking is a loopstick resonated on 60 > > KHz > > > and most likely driving it push pull or single ended. Thats 1 > transistor > > if > > > single ended as common collector if I had to guess. The reason is the > > > micros put out a fair level of signal so its a case of upping current > > into > > > the antenna. But it really will be a bit of experimenting. > > > I did look at your code and that was so nice it opened up straight into > > the > > > arduino IDE. > > > Regards > > > Paul > > > WB8TSL > > > > > > On Thu, Aug 30, 2018 at 5:12 AM, Wayne Holder > > > wrote: > > > > > > > For anyone trying out my ATTiny85 code, I've done some additional > test
Re: [time-nuts] WWVB Signal Generator
For anyone trying out my ATTiny85 code, I've done some additional tests and find that placement of the antenna near the clock is very finicky and, so far, the only way to get a reliable decode of the time in the clock is by using a scope to monitor the demodulated output and then moving the antenna around until the demodulated signal lines up cleanly with modulated carrier and there are no intra bit glitches. This can take a bit of patience, so clearly a better solution needs to be found. I've found that any type of glitch in the demodulated signal seems to prevent the clock chip from decoding the time. It's possible the difficultly with locking onto my simulated WWVB signal may be partially due to the design of the clock (from my location it's never been able to to lock onto the real WWVB signal), but I have no reference to compare it against so, for now, I have conclude that the PWM-based modulation scheme my code uses may also be suboptimal for this application. To make testing even more frustrating, the BALDR clock I'm using will only look for a signal for about 6 minutes before it goes to sleep and I have to then power cycle the clock to get it to listen again. So, keep this in mind if you're going to try and replicate my results. Wayne On Wed, Aug 29, 2018 at 6:03 PM Wayne Holder wrote: > For those that have asked for my to publish the source code for my > ATTiny85-based WWVB simulator, I have put up a somewhat hurriedly written > page on my google site at: > > https://sites.google.com/site/wayneholder/controlling-time > > that describes a bit about how the code works, how to compile it using the > Arduino IDE, how I tested it, some issues I have observed in testing it > and, at the bottom of the page, a downloadable zip file that contains the > complete source code. > > Note: as mentioned at the top of this page, this is currently a work in > process, so I'm not yet going to link the article to my main website page, > so you'll need to link in this post to find it. Also, as draft, I'm going > to continue to revise the page until I feel the project is complete enough > to publish. That means the source code zip file is going to potentially > change from time to time, too. > > Wayne > > On Wed, Aug 29, 2018 at 1:35 AM Wayne Holder > wrote: > >> As a follow up, I now have a simple WWVB simulator written in C that's >> now running an an ATTiny85 using nothing more than the internal, 8 >> mHz oscillator and about a 6 inch length of wire connected to one of the >> pins as an antenna. It generates an approximate 60 kHz signal using PWM on >> timer 1. I tweaked the timer value a bit to correct for some variance in >> the internal oscillator, but I' not even sure that was necessary, as my >> target is just a BALDR Model B0114ST, consumer grade "Atomic" clock. >> Modulation is done by varying the duty cycle of the PWM to approximate the >> -17 dBr drop on the carrier. But, again, I don't think this value is >> critical with a consumer clock chip. I tapped the demodulated output >> inside the clock and displayed it on my scope along with the generated >> signal and I got good, steady demodulation with the wire antenna just >> placed near clock. The next step is to connect up a GPS module and add >> code to use it to set the time. I'm also going to change the code to use >> the PPS signal from the GPS to drive the output timing rather than the test >> code I have now that uses timer 0 to generate the PPS interrupt. I'm happy >> to share details if anyone is interested. >> >> Wayne >> >> >> >> On Sun, Aug 26, 2018 at 2:51 PM, paul swed wrote: >> >>> That would be a great neighbor to have but I can tell you around here its >>> the phone. Not to concerned about someone putting up a wwvb replacement. >>> And I can always up the power. Chickle. >>> Regards >>> Paul >>> >>> On Sun, Aug 26, 2018 at 2:34 PM, Bob kb8tq wrote: >>> >>> > Hi >>> > >>> > The gotcha is if you have neighbors two or three doors away that *also* >>> > put up one of >>> > these devices. You then have a real problem with the neighbor(s) in the >>> > middle. The >>> > wavelength is long enough that Raleigh issues won’t get you. You still >>> > have the two >>> > signals ( at slightly different frequencies) beating against each >>> other. >>> > The result is >>> > going to show up as who knows what to this or that receiver. With a >>> > precision receiver, >>> > you might even have issues from the guy two houses away …... >>> > >
Re: [time-nuts] NIST
Hello to the group. The Chronverter is now available again. US $37. Its from unusual electronics as was mentioned earlier in the thread. No matter how 2019 actually goes its a good way to keep the wwvb clocks going. Saves me from having to create the same thing. Regards Paul WB8TSL On Mon, Aug 13, 2018 at 8:39 AM, jimlux wrote: > On 8/12/18 8:40 AM, Craig Kirkpatrick wrote: > >> I agree with Bob that shutting down WWVB would not go over well with the >> voters but losing WWV and WWVH will mainly be noticed only by HAMs. >> > > > WWV/WWVH also provides HF propagation forecasts, severe weather warnings > for mariners, etc., as well as being a propagation beacon. > > I don't think HF communications is completely going away - it's unique in > not requiring any infrastructure to achieve world-wide communications other > than the two endpoints of the link. > > It's probably a smaller population than radio amateurs, but there are > people who work with HF propagation on a day to day basis. For example, if > Rocketlabs ever gets their act together and launches a couple more rockets, > I'll have a spacecraft in LEO for which I intend to use WWV and WWVH as > calibration sources. > > > > > > > ___ > 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] NIST
With any luck, the current administration will successfully push the USA down technically. Denying global warming, shutting off time signals, and so on, is great stuff. On Saturday, August 11, 2018, 6:10:12 PM PDT, Bob kb8tq wrote: Hi One would *guess* that stopping WWVB (and killing mom and pop’s “atomic clocks”) would not be a reasonable thing to do. It gets a lot of voters mad. I doubt that very many voters (percentage wise) would notice WWV and WWVH going away …. Bob > On Aug 11, 2018, at 9:00 PM, jimlux wrote: > > On 8/10/18 12:45 PM, Robert LaJeunesse wrote: >> I'd say it does get more detailed, with the $49M in cuts described generally >> in groups here: >> https://www.nist.gov/director/fy-2019-presidential-budget-request-summary/fundamental-measurement-quantum-science-and >> One item: "-$6.3 million supporting fundamental measurement dissemination, >> including the shutdown of NIST radio stations in Colorado and Hawaii" > > I wonder if that's WWVB, or WWV & WWVH > > ___ > 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 Signal Generator
Great to see the threads. Take a look at the Chronverter. https://unusualelectronics.co.uk/products/chronvertor/ Its done all of this. I don't get anything by promoting Daves design. But am having very good success with it on my Spectracom and Truetime clocks. I would like to look at the code because I can already see some changes I would like to do. But all in all its very clever. Regards Paul WB8TSL On Sat, Aug 25, 2018 at 3:09 PM, Peter Vince wrote: > Hi Mark, > > If you were able to include optional modulation for the UK's MSF > signal as well as WWVB, then I'd be very interested - especially if you > could persuade John and TAPR to produce a kit :-) Europe's DCF would also > be a good selling point, but getting its 77.5KHz would be more difficult. > > Peter > > > On 25 August 2018 at 19:28, Mark Sims wrote: > > > If I was going to do it I would take a cheap Ublox 7M board (around $10 > > with antenna), program one of the time pulse outputs for 60 kHz (it > > divides evenly into 48 Mhz so no jitter), feed the Ublox serial data / > > 1PPS to an AVR chip (or $2 Arduino Nano clone), and use that to modulate > > the 60 KHz output. Total cost less than $20 and should get to to the > > microsecond level range. > > ___ > > 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 Signal Generator
As a follow up, I now have a simple WWVB simulator written in C that's now running an an ATTiny85 using nothing more than the internal, 8 mHz oscillator and about a 6 inch length of wire connected to one of the pins as an antenna. It generates an approximate 60 kHz signal using PWM on timer 1. I tweaked the timer value a bit to correct for some variance in the internal oscillator, but I' not even sure that was necessary, as my target is just a BALDR Model B0114ST, consumer grade "Atomic" clock. Modulation is done by varying the duty cycle of the PWM to approximate the -17 dBr drop on the carrier. But, again, I don't think this value is critical with a consumer clock chip. I tapped the demodulated output inside the clock and displayed it on my scope along with the generated signal and I got good, steady demodulation with the wire antenna just placed near clock. The next step is to connect up a GPS module and add code to use it to set the time. I'm also going to change the code to use the PPS signal from the GPS to drive the output timing rather than the test code I have now that uses timer 0 to generate the PPS interrupt. I'm happy to share details if anyone is interested. Wayne On Sun, Aug 26, 2018 at 2:51 PM, paul swed wrote: > That would be a great neighbor to have but I can tell you around here its > the phone. Not to concerned about someone putting up a wwvb replacement. > And I can always up the power. Chickle. > Regards > Paul > > On Sun, Aug 26, 2018 at 2:34 PM, Bob kb8tq wrote: > > > Hi > > > > The gotcha is if you have neighbors two or three doors away that *also* > > put up one of > > these devices. You then have a real problem with the neighbor(s) in the > > middle. The > > wavelength is long enough that Raleigh issues won’t get you. You still > > have the two > > signals ( at slightly different frequencies) beating against each other. > > The result is > > going to show up as who knows what to this or that receiver. With a > > precision receiver, > > you might even have issues from the guy two houses away …... > > > > Bob > > > > > On Aug 26, 2018, at 1:08 PM, paul swed wrote: > > > > > > Agree with the conversation. With respect to neighbors when the day > comes > > > they may ask you to boost your signal. :-) > > > Granted maybe the day won't come but at least having your local clocks > > work > > > is nice. > > > Regards > > > Paul > > > WB8TSL > > > > > > On Sat, Aug 25, 2018 at 10:29 PM, Dana Whitlow > > > wrote: > > > > > >> With the watch being physically close to the faux WWVB "transmitter", > > one > > >> is in > > >> the so-called "near field" regime, where the field strength (V/m) > falls > > as > > >> the inverse > > >> cube of the distance. If one is putting the watch, say, within a few > > >> inches of the > > >> transmitter, reliable reception should be available yet the signal > > should > > >> be literally > > >> undetectable by any practical receiving device more than a few feet > > away. > > >> Hence, > > >> meeting the FCC field strength limit should be trivial.if the device > is > > >> used as pictured. > > >> However, if one cranks up the power enough to reliably cover one's > > entire > > >> house, > > >> then there might be a problem depending how close the nearest neighbor > > >> lives, > > >> even at levels well within the FCC limit he quotes. > > >> > > >> Taking the near field relationship in hand, 40 uV/m at 300m would > > translate > > >> into > > >> a whopping 0.135 V/m at 20 meters range, more than enough to feed most > > >> peoples' > > >> entire house. So the pragmatic issue would again be- neighbors. On > the > > >> other > > >> hand, most of them would never be aware of the local signal as long as > > they > > >> get good > > >> time settings, unless they live close enough to Ft. Collins for the > two > > >> signals to > > >> contend with each other. > > >> > > >> It looks to me like the ferrite rod antenna is considerable overkill. > > Even > > >> with no > > >> purposeful antenna I'd expect leakage to yield sufficient signal for > at > > >> least a few > > >> inches. > > >> > > >> Dana > > >> > > >> > > >> On Sat, Aug 25, 2018
Re: [time-nuts] WWVB Signal Generator
Wayne always fun to see what others are doing and to learn. I would imagine the programs pretty small and could be attached here. How will you handle DST? Its a bit messy as a recent thread detailed. Plus the fact that god knows why politicians like to screw with it. Regards Paul WB8TSL On Wed, Aug 29, 2018 at 4:35 AM, Wayne Holder wrote: > As a follow up, I now have a simple WWVB simulator written in C that's now > running an an ATTiny85 using nothing more than the internal, 8 > mHz oscillator and about a 6 inch length of wire connected to one of the > pins as an antenna. It generates an approximate 60 kHz signal using PWM on > timer 1. I tweaked the timer value a bit to correct for some variance in > the internal oscillator, but I' not even sure that was necessary, as my > target is just a BALDR Model B0114ST, consumer grade "Atomic" clock. > Modulation is done by varying the duty cycle of the PWM to approximate the > -17 dBr drop on the carrier. But, again, I don't think this value is > critical with a consumer clock chip. I tapped the demodulated output > inside the clock and displayed it on my scope along with the generated > signal and I got good, steady demodulation with the wire antenna just > placed near clock. The next step is to connect up a GPS module and add > code to use it to set the time. I'm also going to change the code to use > the PPS signal from the GPS to drive the output timing rather than the test > code I have now that uses timer 0 to generate the PPS interrupt. I'm happy > to share details if anyone is interested. > > Wayne > > > > On Sun, Aug 26, 2018 at 2:51 PM, paul swed wrote: > > > That would be a great neighbor to have but I can tell you around here its > > the phone. Not to concerned about someone putting up a wwvb replacement. > > And I can always up the power. Chickle. > > Regards > > Paul > > > > On Sun, Aug 26, 2018 at 2:34 PM, Bob kb8tq wrote: > > > > > Hi > > > > > > The gotcha is if you have neighbors two or three doors away that *also* > > > put up one of > > > these devices. You then have a real problem with the neighbor(s) in the > > > middle. The > > > wavelength is long enough that Raleigh issues won’t get you. You still > > > have the two > > > signals ( at slightly different frequencies) beating against each > other. > > > The result is > > > going to show up as who knows what to this or that receiver. With a > > > precision receiver, > > > you might even have issues from the guy two houses away …... > > > > > > Bob > > > > > > > On Aug 26, 2018, at 1:08 PM, paul swed wrote: > > > > > > > > Agree with the conversation. With respect to neighbors when the day > > comes > > > > they may ask you to boost your signal. :-) > > > > Granted maybe the day won't come but at least having your local > clocks > > > work > > > > is nice. > > > > Regards > > > > Paul > > > > WB8TSL > > > > > > > > On Sat, Aug 25, 2018 at 10:29 PM, Dana Whitlow < > k8yumdoo...@gmail.com> > > > > wrote: > > > > > > > >> With the watch being physically close to the faux WWVB > "transmitter", > > > one > > > >> is in > > > >> the so-called "near field" regime, where the field strength (V/m) > > falls > > > as > > > >> the inverse > > > >> cube of the distance. If one is putting the watch, say, within a > few > > > >> inches of the > > > >> transmitter, reliable reception should be available yet the signal > > > should > > > >> be literally > > > >> undetectable by any practical receiving device more than a few feet > > > away. > > > >> Hence, > > > >> meeting the FCC field strength limit should be trivial.if the device > > is > > > >> used as pictured. > > > >> However, if one cranks up the power enough to reliably cover one's > > > entire > > > >> house, > > > >> then there might be a problem depending how close the nearest > neighbor > > > >> lives, > > > >> even at levels well within the FCC limit he quotes. > > > >> > > > >> Taking the near field relationship in hand, 40 uV/m at 300m would > > > translate > > > >> into > > > >> a whopping 0.135 V/m at 20 meters range, more than enough to feed > most > > > >
Re: [time-nuts] Loss of NIST transmitters at Colorado and Hawaii
I don’t know if it’s on-topic or not, but my talking clock now has a WWV #define for the firmware. Mind you, all that really does is change it to 59 ticks and one beep and a single time announcement in the last 10 seconds of the minute. https://hackaday.io/project/28949-gps-talking-clock > On Sep 7, 2018, at 2:49 PM, paul swed wrote: > > Nick > Been watching the thread and building a replacement for wwvb. Cause darn it > I like my spot specific always accurate clocks. However that said the next > generations of time users for general life only have one clock and its next > to their keister. They are mobile and heavens actually getting to a meeting > on time is not as important as finishing that text. I believe our > perspective is seriously skewed by time. The fact that the mobile clock is > a bit one way or another just isn't much of a factor. Mobile phone time is > good enough. > There are lots of changes going on such as watching video whenever and > however at anytime. > So after I figure how to get a bit of 60 KHz energy going around the house, > it will be off to making a local wwv replacement. > The old radios just don't have a ethernet port on them. Ticks are easy the > voice really tough. > Regards > Paul > WB8TSL > > On Fri, Sep 7, 2018 at 4:24 PM, Nick Sayer via time-nuts < > time-nuts@lists.febo.com> wrote: > >> My own perspective is that embedded devices with WiFi present a monstrous >> user interface barrier. You have to somehow communicate the WiFi SSID and >> WPA credentials to the device. Some embedded things have displays and input >> methods and can at least use the “ouija board” method (which is still a >> pain in the keister), but truly embedded things like wall clocks? There >> you’re going to have to rely on ugly hacks like “set up networks” with web >> servers running on them and so on. It’s a mess at best. >> >> Where the embedded device provides value sufficient to overcome the >> barriers, then it makes sense. I have a whole bunch of IoT devices in our >> house and the added convenience they give made it absolutely worth the >> configuration steps asked. But a wall clock? I can imagine the negative >> Amazon reviews already. >> >> Others have argued for GPS clocks. GPS is certainly an alternative to >> WWVB, but it has a different set of challenges and benefits. It’s far, far >> more accurate, but it’s also more expensive, requires better antenna >> placement and requires enough power that a battery operated clock isn’t >> terribly practical, certainly compared to WWVB. >> >> I can *kinda* see the impetus behind shuttering WWVH and perhaps WWV. But >> WWVB is currently used by hundreds of thousands if not millions of devices. >> I think it’s kind of a rotten deal to just pull the plug on them without at >> least a number of years of warning. >> >>> On Aug 13, 2018, at 5:07 AM, Tim Shoppa wrote: >>> >>> While consumer WWVB clocks are widespread today, almost all (or all) >> professional clock displays have shifted to NTP over copper or over >> sometimes WIFI in the past decade. >>> >>> WWVB or WWV, without an external antenna, was never a good choice for a >> clock in a steel building to begin with. 30 years ago you would put an HF >> or GOES antenna on the roof. As the paperwork for putting up an antenna has >> multiplied exponentially and Ethernet has become completely and totally >> ubiquitous in commercial buildings, it becomes a no brainer to choose a POE >> NTP clock display. >>> >>> While NTP works super well for locations with 120VAC or POE power, it is >> not so obvious for a wallclock that is traditionally powered by a battery >> that only has to be changed every few years. For battery powered wallclocks >> in wood buiildings WWVB is still a great solution maybe even the only >> solution. But I could imagine a consumer product that just turned on its >> WIFI for a minute each day to resync and was battery powered. >>> >>> Tim N3QE >>> >>>> On Aug 13, 2018, at 12:28 AM, Richard (Rick) Karlquist < >> rich...@karlquist.com> wrote: >>>> >>>> >>>> >>>>> On 8/12/2018 6:55 PM, John C. Westmoreland, P.E. wrote: >>>>> I hope this does not happen. I get questions from new Hams that ask, >> 'How >>>>> can I check my antenna easily?' - the quick reply is to check for WWV >> on >>>>> 2.5, 5,0, 10.0, 15.0 and 20.0 MHz. >>>> >>>> W1AW is far more useful to check ham antennas, since it broadcasts >>&g
Re: [time-nuts] Lots of Off Topic discussion
Does any one know what the line item $$$ amount is for the WWV/WWVB operating budget? -DC NR1DX manu...@artekmanuals.com On 9/1/2018 11:59 PM, Peter Laws wrote: On Sat, Sep 1, 2018 at 7:25 PM Bob kb8tq wrote: I most certainly *have* seen an NTP server that ran off of WWVB and relayed the result to the internet. The fun part was that they had entered the “delay” I didn't say it COULD not -- W3HCF and his group didn't miss much in the code -- but what I'm saying is that in 20+ years of dinking with NTP as part of my job, I HAVE not seen any evidence of WWV being used as a "refclock". Certainly not in the last decade. Maybe there were many of them when Dr Mills first published the standards and reference implementation back in the 1980s but not now. I want to be outraged over this cut but until I have a coherent, evidence-based argument in favor of keeping the stations, I'm going to keep my powder dry. -- Dave manu...@artekmanuals.com www.ArtekManuals.com --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ___ 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] new WWVB BPSK dev board
Good morning I agree that 1deg is overkill but I was simply extrapolating one extra decade from BOB kb8tq's "backing off a bit" comment where he got down to 10deg. :-) 10MHz is an obvious sample rate - sorry, that fell into a blind spot here! I think I will get distracted over Christmas sketching out some designs ... Thanks - John -Original Message- From: Poul-Henning Kamp [mailto:p...@phk.freebsd.dk] Sent: 4 December, 2018 11:03 PM To: Discussion of precise time and frequency measurement ; John Moran, Scawby Design Subject: Re: [time-nuts] new WWVB BPSK dev board In message mailto:am0pr03mb4129fbd0922805fc14b8cefde4...@am0pr03mb4129.eurprd03.prod.outlook.com>>, "John Moran, Scawby Design" writes: >However, fast A-Ds are not particularly cheap and you would need circa >50MHz sample rate to resolve 1deg of the carrier, and TVB has already >stated that there are no time benefits to BPSK, so this is all just an >interesting technical exercise, isn't it? I admit it would be interesting to do the allan variance on it, but measuring the carrier to 1 degree in every single cycle is way overkill. 1 MHz sampling rate is fine, but go for 5 or 10 MHz so you can drive the ADC directly from your house-standard. And BPSK *does* improve the timing, because you can very precisely measure when the change of phase happens, and it since it happens at a carrier zero-crossing you can filter it down to +/- sample. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org<mailto:p...@freebsd.org> | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@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] new WWVB BPSK dev board
For other reasons and other bands (650m), I am very interested in narrow band SDR, but I have not found a platform to get started on. -Original Message- From: time-nuts On Behalf Of Poul-Henning Kamp Sent: Tuesday, December 4, 2018 1:31 PM To: Discussion of precise time and frequency measurement ; Bob kb8tq Subject: Re: [time-nuts] new WWVB BPSK dev board >We’ve been chatting about how drop dead simple it is to spend a couple >minutes and come up with a SDR for the new modulation for …. ummm ….. >errr …. how many years now? :) So far not a lot has turned up. All I can say is that people dont know what they're missing ;-) -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@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] new WWVB BPSK dev board
Hi We’ve been chatting about how drop dead simple it is to spend a couple minutes and come up with a SDR for the new modulation for …. ummm ….. errr …. how many years now? :) So far not a lot has turned up. Bob > On Dec 4, 2018, at 3:14 PM, Poul-Henning Kamp wrote: > > > In message <63462681-f5d7-0282-ef5b-82e8332d0...@dartmouth.edu>, "David G. > McGaw" writes: > >> BTW, I have been told it has also been successfully tested for lock in >> Brazil. Is there anyone in Australia want to give it a try? Perth is >> almost directly opposite Fort Collins. :-) > > Write a WWVB extension to KiwiSDR so you can try it all over the world ? > > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > p...@freebsd.org | TCP/IP since RFC 956 > FreeBSD committer | BSD since 4.3-tahoe > Never attribute to malice what can adequately be explained by incompetence. > > ___ > time-nuts mailing list -- time-nuts@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] new WWVB BPSK dev board
On 12/4/18 12:21 PM, Bob kb8tq wrote: Hi We’ve been chatting about how drop dead simple it is to spend a couple minutes and come up with a SDR for the new modulation for …. ummm ….. errr …. how many years now? :) So far not a lot has turned up. if someone will digitize the signal at some reasonable data rate and bit depth and send me some minutes of data, I'll see if I can code up a simple decoder that would run on a low end processor. It's just BPSK at 1 bit/second, after all. I maintain that it's the lack of a cheap RF front end that is the sticky point. Bob On Dec 4, 2018, at 3:14 PM, Poul-Henning Kamp wrote: In message <63462681-f5d7-0282-ef5b-82e8332d0...@dartmouth.edu>, "David G. McGaw" writes: BTW, I have been told it has also been successfully tested for lock in Brazil. Is there anyone in Australia want to give it a try? Perth is almost directly opposite Fort Collins. :-) Write a WWVB extension to KiwiSDR so you can try it all over the world ? -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@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] new WWVB BPSK dev board
Hi Nigel I moved from Warwickshire to west Sussex south of the downs 20 years ago and all was OK But since it moved I have not bean able to use the 60 Khz reference I am thinking of setting up a reference to use the one in France I think it is 192 Khz And then I can do a frequency difference between the 2 Also Looking for a rabid Best regards Paul -Original Message- From: time-nuts [mailto:time-nuts-boun...@lists.febo.com] On Behalf Of gandalfg8--- via time-nuts Sent: 04 December 2018 12:12 To: time-nuts@lists.febo.com Cc: gandal...@aol.com Subject: [time-nuts] new WWVB BPSK dev board Hi Paul, It was shifted over 11 years ago, very obligingly timed to follow my move from the South East to Scotland:-), so I suspect any resulting propogational changes would have been well documented by now. Nigel GM8PZR Hi thank you Bob for the mail Do you realise the 60 Khz Transmitter in the UK was moved from Rugby in the centre of England north by more than 200 miles Paul ___ 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] new WWVB BPSK dev board
Hi Given the large “fade” of WWVB over a 24 hour period (it’s not always ground wave ….) most decent receivers in the past have run a front end with AGC on it. Indeed 24 bit ADC’s ( > 16 bit ENOB) are out there for not a massive amount of money. It is a bit unclear just how much fade you need to compensate for until you get past the “that’s enough” point. There are a number of nasty points in the country you would need to check out. Since you also are trying to deal with an enormous amount of “crud” at the same time, there may not be an exact answer. Bob > On Dec 4, 2018, at 4:48 PM, Attila Kinali wrote: > > On Tue, 4 Dec 2018 13:12:48 -0800 > jimlux wrote: > >> I maintain that it's the lack of a cheap RF front end that is the sticky >> point. > > Doing a 2-3 stage transistor based amplifier should give the signal > enough gain to be sampled with the ADC of a uC. I have such a design > sitting around, that I did a couple of years back for DCF77, but never > got around to actually built it (see attachment). > > It is meant to be run from 4V, so that one can use an unstable/noisy > 5V source with an 4V LDO and should give ~70dB of total gain. I used > BC547 in the simulation, but any NPN with decent h_fe and f_t should > do (eg 2N, 2N3904,...). The 2N5484 is a bit harder to replace, > as I selected it for its low V_th and narrow specified V_th range. > > All that is needed for this to work is a tuned antenna, ie a ferrite > rod with a capcitor on it that is approximately tuned to 60/77.5kHz. > > Attila Kinali > > -- > The bad part of Zurich is where the degenerates >throw DARK chocolate at you. > ___ > 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] new WWVB BPSK dev board
In message <20181204222100.293dc3259cf1d8683daec...@kinali.ch>, Attila Kinali writes: >BPSK by itself does not improve timing. At most it improves reception >by having a constant power envelope. But in case of WWVB, where >the AM modulation is still kept, this is not the case. The phase >changes do not help reception at all. In order to help reception, >one needs to send a _known_ bit string in order for a corrolator >in the receiver to pick the signal out of the noise. They do that in the "long" sequence, read their spec. The fact that it is one out of 100-some known sequences does not significantly change that situation. And the BPSK does improve timing. If you have access to, and tracks the carrier, you can nail the timing all the way down to 1/your_sample_rate. Been there, done that with DCF77 no big deal. Even the weird phase-modulation of RDF and BBC on 198kHz can be nailed down very precisely that way. But the crucial thing is: You need to digitize the carrier. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@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] new WWVB BPSK dev board
Hi, In France the carrier frequency is 162khz (Allouis) Phase modulated over one minute. Gilles. Envoyé de mon iPad > Le 5 déc. 2018 à 00:57, Paul Bicknell a écrit : > > Hi Nigel > > I moved from Warwickshire to west Sussex south of the downs 20 years ago > and all was OK But since it moved I have not bean able to use the 60 Khz > reference I am thinking of setting up a reference to use the one in France > I think it is 192 Khz > And then I can do a frequency difference between the 2 > Also Looking for a rabid > > Best regards Paul > > -Original Message- > From: time-nuts [mailto:time-nuts-boun...@lists.febo.com] On Behalf Of > gandalfg8--- via time-nuts > Sent: 04 December 2018 12:12 > To: time-nuts@lists.febo.com > Cc: gandal...@aol.com > Subject: [time-nuts] new WWVB BPSK dev board > > Hi Paul, > > It was shifted over 11 years ago, very obligingly timed to follow my move > from the South East to Scotland:-), > > so I suspect any resulting propogational changes would have been well > documented by now. > > Nigel GM8PZR > > Hi thank you Bob for the mail > > Do you realise the 60 Khz Transmitter in the UK was moved from Rugby in the > centre of England north by more than 200 miles > Paul > ___ > 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] new WWVB BPSK dev board
Sorry about that garbled link. Blame Dartmouth's over-zealous IT. Just look for "rtl-sdr direct sampling mode" at rtl-sdr dot com. On 12/4/18 11:09 PM, David G. McGaw wrote: > Actually, an RTL-SDR can because there is direct access to the ADC > available by soldering to internal pads: > https://na01.safelinks.protection.outlook.com/?url=www.rtl-sdr.com%2Frtl-sdr-direct-sampling-mode%2Fdata=02%7C01%7Cdavid.g.mcgaw%40dartmouth.edu%7C26d18a151e124b336e5008d65a679402%7C995b093648d640e5a31ebf689ec9446f%7C0%7C0%7C636795798255645762sdata=k7qbMd66xKxoL28CemtFlw5cbhLHMgU01NZlOnfY7Lw%3Dreserved=0 > That will give you 8-bit, > 14.4Msps. > > But as has also been said, a good sound card sampling 24 bits at 192kHz > can be used. > > David N1HAC > > > On 12/4/18 6:54 PM, Poul-Henning Kamp wrote: >> >> In message <2e7cf0ff-4094-2750-4874-96dfe2efe...@earthlink.net>, jimlux >> writes: >> >>> I'm going to bet that the 8 bit RTL-SDR isn't going to work on 60kHz. >> I don't know about the RTL-SDR, but 8 bits will get you quite far with >> slow moving time signals like WWVB because you can average for minutes >> if you want - provided you feed the ADC a good stable clock. >> > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Flists.febo.com%2Fmailman%2Flistinfo%2Ftime-nuts_lists.febo.comdata=02%7C01%7Cdavid.g.mcgaw%40dartmouth.edu%7C26d18a151e124b336e5008d65a679402%7C995b093648d640e5a31ebf689ec9446f%7C0%7C0%7C636795798255645762sdata=uiRL44S%2BpMemw1SzGs2tBRyaFEchYGgaCnYzOVd8bNM%3Dreserved=0 > 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] Portable Time Standard
Hi The most common approach to “monitor” a quartz movement is to listen to it at 32,768 KHz with a tuned microphone. If it is an analog movement, then one can detect the sound of the motor driving the mechanical side. Do you need a device with a visual readout or are you after something that gives you an electrical signal (like a PPS)? Is DIY ok in this application? If so, there are a lot of TCXO’s out there that will do at least as well as what you are looking for. A very different approach would be a GPS (or WWVB) module with a battery attached to it. If a watch is “ok”, there are WWVB and GPS watches that will do much better than 1 second accuracy for not very insane sort of prices. Bob > On Jan 11, 2019, at 2:57 PM, Joe Hobart wrote: > > I need a relatively lightweight, self powered, portable clock accurate to 1 > second per month. Temperatures may range from 10 to 35 C; altitude from 1000 > to > 7000 feet. Although expensive, some of the marine quartz chronometers appear > to > meet this requirement. ~0.3 PPM. > > Does anyone have any experience with these devices? > > If so, has anyone tried to detect the probably weak magnetic field generated > by > the clock mechanism for time comparison purposes? > > Thanks, > Joe, W7LUX > > --- > This email has been checked for viruses by AVG. > https://www.avg.com > > > ___ > 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] WWV 100 Year Celebration
Just an FYI, WWV will celebrate 100 years on the air in October of this year. They will have an open house an recognition ceremony in Fort Collins on Tuesday, October 1st. My amateur radio club (NCARC), is sponsoring a special event amateur radio station, call sign WW0WWV from September 28-October 2 on the WWV/WWVB transmitter property in north Fort Collins. Note that the WWV/WWVB transmitter site does not do tours often, so if you've never visited the site, this might be a good time to check it out, especially since the station seems to get put on the chopping block on an annual basis these days. If you are an amateur radio operator you may want to participate in the event, either by contacting the station, or taking a trip to Fort Collins and possibly being an operator. More details can be found at: http://wwv100.com https://www.nist.gov/news-events/events/2019/10/nist-radio-station-wwv-100-year-anniversary Regards, John P.S. I am not a contact person for this event, and don't know any more details about the NIST open house other than what is posted. Hopefully more details will be posted in the future. ___ 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] ES100 suddenly more sensitive in summer!
Tim I plan to listen for the Swedish station SAQ on Sunday at 17.2KHz. So testing the equipment. What I am seeing is that LED lighting in general is covering the low spectrum with lots of noise. In fact in our town they just replaced every street light with a bright harsh white LED Fixture. So as a theory I wonder if what we expect at night, isn't true anymore since the street lights are on all night. I have not taken a listen yet to wwvb. But fear it will be some bad news. Regards Paul WB8TSL On Sat, Jun 29, 2019 at 11:00 AM Tim Shoppa wrote: > Interestingly enough, compared to my initial testing last winter, my ES100 > is suddenly much more likely to acquire and track WWVB in broad daylight. > This morning it is acquiring from a cold start almost every time. > > (The "bad minutes" of course still don't work). > > Most likely reason would be some reduction in my local noise sources but > wonder if something more propagation-wise is going on. > > For sure I expected 60kHz propagation from Colorado to Maryland to be more > reliable in common darkness and in winter, and less reliable in summertime > and common daylight, but perhaps this is a faulty mental model I have. > > 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. > ___ 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 Dephaser Question
John had not seen this before. It is a AM decoder. But its an interesting start if you are less than 1000 miles from wwvb. Regards Paul On Mon, Oct 12, 2020 at 6:52 AM John C. Westmoreland, P.E. < j...@westmorelandengineering.com> wrote: > Paul, > > Doesn't the post by Chris Howard above appear to be a good/great starting > point? > Seems like that approach could be extended. > > https://github.com/chris-elfpen/Teensy4WWVBsdr > > 73's, > John > AJ6BC > > > On Sun, Oct 11, 2020 at 9:23 AM paul swed wrote: > > > Good morning to the group. Both Rodger and I can answer the last question > > on the questionable bits very well. > > I have 7 antique devices spectracoms truetime fluke tracor Dymec etc. > > They handle it very well each has at least a 2 second integration time. > The > > dpskr has always taken advantage of this fact. Literally we have run days > > without flips in the charts. Even in summer. > > Some surprises in doing this. Numbers of bits that could change don't > seem > > to. Then some of the bits have a really odd pattern but they follow the > > pattern. Thats been coded into the dpskr. In fact anything over several > > years we have figured out are coded in. > > One thing we did not do was automatic change from summer to winter > offsets. > > Its really a PIA so just not that excited when this happy switch flipper > > can do it in 1 second. > > > > The other bit of fun for the magical new DPS wwvb receiver is after you > get > > the bits you must decode them and its nothing like the AM code. Its a M/N > > FEC code. Its all in the NIST papers but was fun coding and I imagine > every > > bit as fun decoding. The dpskr software at least gives you hints to the > > process. > > > > Here is an offer. Anyone that gets the BPSK bits working through a > SDR/DPS > > arduino/STM cheap chip. Please no $100 FPGA development kits. > > I will be happy to dig into the decoder. The solution needs a 1pps and > the > > bit. > > Whats really funny about the wwvb bpsk is that there has never been sort > of > > a open development platform. Anyone who has played with the ES100 will > run > > into some issues that are annoying for a time nut to tinker with. > > Regards > > Paul > > > > On Sun, Oct 11, 2020 at 10:39 AM Bob kb8tq wrote: > > > > > Hi > > > > > > The “simple” approach is to generate the full modulation pattern > > > for the signal based on a “known good” time source. There are a > > > couple of ambiguous bits so it will only be close. Feed that into > > > your inverter and the result will be (near) clean WWVB. Since you > > > never demodulate the WWVB, there isn’t a lot to the RF side …. > > > > > > There will be some drops and pops. The question will be just how > > > well this or that antique device deals with them. > > > > > > Bob > > > > > > > On Oct 10, 2020, at 10:01 PM, paul swed wrote: > > > > > > > > The additional article John sent us is a pretty good read. Having > > > soldered > > > > all the little wires together with heat shrink, I can see the > advantage > > > of > > > > the epoxy approach. > > > > > > > > A consideration for the discussion. So far its been about the various > > > tried > > > > and true methods for a RF frontend. But the real challenge that is in > > > front > > > > of us is the software that uses that frontend. How about a very easy > to > > > > build a phase flipper so that those that are software inclined do not > > > need > > > > to deal with the frontend to get going. The dpskr has a phase flipper > > in > > > it. > > > > But it can be even simpler than that. > > > > > > > > A 60 KHz logic signal ( divide 6 Mhz down or anything else thats > easy) > > > > Feeds an inverter to generate the 180 degree phase. A gate to select > 0 > > or > > > > 180 degrees. All of the gates/inverters can actually be a single quad > > > > nand gate. A D flip flop with the clock from the 0 degree 60 KHz > logic > > > > level. Your data into the D input. The D flip flop synchronizes the > > data > > > to > > > > the clock. On the output you can filter the signal or not and cut the > > > level > > > > down or not. > > > > Its a BPSK source. > > > > Granted in a pure gate approach the actual bpsk flip will not be the > 2 > > X >
Re: [time-nuts] WWVB Dephaser Question
John really appreciate the pointer. Though it doesn't help wwvb BPSK its a really good intro to SDR and DSP super simple. A good way to get your feet wet. Hmmm is there a parts order soon? :-) Regards Paul WB8TSL On Mon, Oct 12, 2020 at 10:33 AM Bob kb8tq wrote: > Hi > > The “ideal” antenna solenoid would be a bit longer ( say 2 X to 5X ). > The turns should be spaced apart by a few percent of the length. > ( so turns over 30 or so … not so much …). > > How much better is “ideal” compared to “just get it done?”. At least > from the stories that are told, it is significant. Since all these antennas > are very small (so non-ideal) it’s a bit of a snail race. > > Bob > > > On Oct 12, 2020, at 3:42 AM, John C. Westmoreland, P.E. < > j...@westmorelandengineering.com> wrote: > > > > Paul, > > > > Doesn't the post by Chris Howard above appear to be a good/great starting > > point? > > Seems like that approach could be extended. > > > > https://github.com/chris-elfpen/Teensy4WWVBsdr > > > > 73's, > > John > > AJ6BC > > > > > > On Sun, Oct 11, 2020 at 9:23 AM paul swed wrote: > > > >> Good morning to the group. Both Rodger and I can answer the last > question > >> on the questionable bits very well. > >> I have 7 antique devices spectracoms truetime fluke tracor Dymec etc. > >> They handle it very well each has at least a 2 second integration time. > The > >> dpskr has always taken advantage of this fact. Literally we have run > days > >> without flips in the charts. Even in summer. > >> Some surprises in doing this. Numbers of bits that could change don't > seem > >> to. Then some of the bits have a really odd pattern but they follow the > >> pattern. Thats been coded into the dpskr. In fact anything over several > >> years we have figured out are coded in. > >> One thing we did not do was automatic change from summer to winter > offsets. > >> Its really a PIA so just not that excited when this happy switch flipper > >> can do it in 1 second. > >> > >> The other bit of fun for the magical new DPS wwvb receiver is after you > get > >> the bits you must decode them and its nothing like the AM code. Its a > M/N > >> FEC code. Its all in the NIST papers but was fun coding and I imagine > every > >> bit as fun decoding. The dpskr software at least gives you hints to the > >> process. > >> > >> Here is an offer. Anyone that gets the BPSK bits working through a > SDR/DPS > >> arduino/STM cheap chip. Please no $100 FPGA development kits. > >> I will be happy to dig into the decoder. The solution needs a 1pps and > the > >> bit. > >> Whats really funny about the wwvb bpsk is that there has never been > sort of > >> a open development platform. Anyone who has played with the ES100 will > run > >> into some issues that are annoying for a time nut to tinker with. > >> Regards > >> Paul > >> > >> On Sun, Oct 11, 2020 at 10:39 AM Bob kb8tq wrote: > >> > >>> Hi > >>> > >>> The “simple” approach is to generate the full modulation pattern > >>> for the signal based on a “known good” time source. There are a > >>> couple of ambiguous bits so it will only be close. Feed that into > >>> your inverter and the result will be (near) clean WWVB. Since you > >>> never demodulate the WWVB, there isn’t a lot to the RF side …. > >>> > >>> There will be some drops and pops. The question will be just how > >>> well this or that antique device deals with them. > >>> > >>> Bob > >>> > >>>> On Oct 10, 2020, at 10:01 PM, paul swed wrote: > >>>> > >>>> The additional article John sent us is a pretty good read. Having > >>> soldered > >>>> all the little wires together with heat shrink, I can see the > advantage > >>> of > >>>> the epoxy approach. > >>>> > >>>> A consideration for the discussion. So far its been about the various > >>> tried > >>>> and true methods for a RF frontend. But the real challenge that is in > >>> front > >>>> of us is the software that uses that frontend. How about a very easy > to > >>>> build a phase flipper so that those that are software inclined do not > >>> need > >>>> to deal with the frontend to get going. The dpskr has a phase flipper > >> in > &g
Re: [time-nuts] WWVB Dephaser Question
On 10/12/20 7:40 AM, paul swed wrote: John really appreciate the pointer. Though it doesn't help wwvb BPSK its a really good intro to SDR and DSP super simple. A good way to get your feet wet. Hmmm is there a parts order soon? :-) Regards Paul WB8TSL And the teensy has plenty of space and speed to implement a PLL for doing BPSK demodulation. On Mon, Oct 12, 2020 at 10:33 AM Bob kb8tq wrote: Hi The “ideal” antenna solenoid would be a bit longer ( say 2 X to 5X ). The turns should be spaced apart by a few percent of the length. ( so turns over 30 or so … not so much …). How much better is “ideal” compared to “just get it done?”. At least from the stories that are told, it is significant. Since all these antennas are very small (so non-ideal) it’s a bit of a snail race. Bob On Oct 12, 2020, at 3:42 AM, John C. Westmoreland, P.E. < j...@westmorelandengineering.com> wrote: Paul, Doesn't the post by Chris Howard above appear to be a good/great starting point? Seems like that approach could be extended. https://github.com/chris-elfpen/Teensy4WWVBsdr 73's, John AJ6BC ___ 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 Dephaser Question
I received a good pointer about doing the BPSK implementation but have just not gotten it done. Chris Howard On 10/12/20 11:02 AM, jimlux wrote: On 10/12/20 7:40 AM, paul swed wrote: John really appreciate the pointer. Though it doesn't help wwvb BPSK its a really good intro to SDR and DSP super simple. A good way to get your feet wet. Hmmm is there a parts order soon? :-) Regards Paul WB8TSL And the teensy has plenty of space and speed to implement a PLL for doing BPSK demodulation. On Mon, Oct 12, 2020 at 10:33 AM Bob kb8tq wrote: Hi The “ideal” antenna solenoid would be a bit longer ( say 2 X to 5X ). The turns should be spaced apart by a few percent of the length. ( so turns over 30 or so … not so much …). How much better is “ideal” compared to “just get it done?”. At least from the stories that are told, it is significant. Since all these antennas are very small (so non-ideal) it’s a bit of a snail race. Bob On Oct 12, 2020, at 3:42 AM, John C. Westmoreland, P.E. < j...@westmorelandengineering.com> wrote: Paul, Doesn't the post by Chris Howard above appear to be a good/great starting point? Seems like that approach could be extended. https://github.com/chris-elfpen/Teensy4WWVBsdr 73's, John AJ6BC ___ 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] What's available in the way of DSP for new WWVB?
On Tue, Oct 13, 2020 at 12:19 PM paul swed wrote: > Graham take a look earlier in the thread there are details about the > teensy. There is actually a lot of hardware out there today for little > money. Thats what makes the SDR DSP approach interesting and for me at > least the next thing to take a run at. > Regards > Paul > WB8TSL > > > Hi Paul: I have looked at the Teensy 4.0 for use as a WWVB SDR receiver. The problems I have are: 1.) PJRC (the designer/manufacturer) has gone out of their way to block access to the standard ARM SWD programming interface, and you must go through the unique USB loader executable and programming interface if you want to program the board. It is awkward to use a normal development environment such as NXP's MCUXpresso with a standard programming interface. It is really intended for use with the provided Arduino programming environment. 2.) If you use the provided Arduino IDE/environment, then the provided DSP functions are restricted to the 16 bit versions. I prefer the ARM 32 bit versions to go with my 19 to 24 bit data converter. 3.) I have found that the iMX RT1062 processor will only run at the advertised 600 MHz speed, if it is exclusively executing from onboard "tightly coupled RAM". If your program is large enough to require using the OCRAM, then it slows down to 1/4 speed. If you need even more memory space, and you try to use the provided external QSPI Flash, then it slows down to about 1/32 speed. What it effectively does is run at some blend of those speeds as it fetches cache and variously accesses the different memories. Memory planning is critical for maximum performance. --- Graham == ___ 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] What's available in the way of DSP for new WWVB?
On 10/16/20 1:54 PM, jimlux wrote: On 10/16/20 9:08 AM, Graham / KE9H wrote: On Tue, Oct 13, 2020 at 12:19 PM paul swed wrote: Graham take a look earlier in the thread there are details about the teensy. There is actually a lot of hardware out there today for little money. Thats what makes the SDR DSP approach interesting and for me at least the next thing to take a run at. Regards Paul WB8TSL Hi Paul: I have looked at the Teensy 4.0 for use as a WWVB SDR receiver. The problems I have are: 1.) PJRC (the designer/manufacturer) has gone out of their way to block access to the standard ARM SWD programming interface, and you must go through the unique USB loader executable and programming interface if you want to program the board. It is awkward to use a normal development environment such as NXP's MCUXpresso with a standard programming interface. It is really intended for use with the provided Arduino programming environment. I'm not so sure about that. There's quite a few folks using ARM toolchains and not using the USB loader. For that matter, if you can generate an executable, in any fashion, you can use their loader. I've done it with a 3.2, but not the 4.0, so maybe there's a hiccup.. But usually, the support forum has a wealth of information. Or TyQT, which is what I use a lot with Teensy boards - it will reflash it, reboot, etc. Yeah, you don't get a debugger - you have to toggle pins and use a scope, or printf() googling Teensy 4.0 ARM SWD might turn up useful stuff. ___ 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 Dephaser Question
Paul, Thanks for that detailed explanation. I've done something similar for MARS but of course higher frequency and that was transmit also. I've seen the site of something similar but I think that was a 3' diameter design; and I've looked at some of the Symmetricom schematics I've been able to find but have yet to find a schematic of one of the Symmetricom receive antennas. I was hoping to find the one they had for outdoor pole mount. It's mentioned in a lot of their documents and even some pics but no schematic details or BOM for that I've been able to find. Thanks to Tim also for the response and have a good weekend! 73's, John AJ6BC On Fri, Oct 9, 2020, 15:24 paul swed wrote: > John I don't think so as not sure how many have built a large antenna. > Certainly any of the old wwvb receivers have details and thats pretty much > what most people copy. > Essentially a 3 foot copper loop with numbers of turns of wire connected > together. Like 25 pair telco cable connected end to end. A large capacitor > is then put across the loop to resonate it at 60 KHz. Then the preamp. Some > use a FET transistor followed by a line driver transistor. Power is sent > over the coax so a blocking cap and inductor. > Really big is 10' by 10' using shielded 36 wire ribbon cable. ( did not use > all 36 conductors it was to much L but 800 ft worth. The shield acts like > the copper pipe and it must be broken so that it does not look like a > shorted loop. Add the cap and preamp. > In this case I built a 2 transistor NPN 2n3904 preamp. > On the large antenna I use a 2 X 6 post 4ft in the ground with cement. A > mast above that to support the antenna and to allow it to be turned a bit > to null MSF. > Thats it no real magic. Its been operational for 7 years with an occasional > transistor replacement. Also coax, darn woodpeckers! > Regards > Paul > WB8TSL > > > On Fri, Oct 9, 2020 at 5:14 PM John C. Westmoreland, P.E. < > j...@westmorelandengineering.com> wrote: > > > Bob, > > > > Thanks for the answer; but does anyone actually have a documented > > specification posted for one of these 'massive' WWVB 60kHz antennas > > someplace? > > > > Thanks. > > > > 73's, > > John > > AJ6BC > > > > > > On Fri, Oct 9, 2020, 08:35 Bob kb8tq wrote: > > > > > Hi > > > > > > At least to me, anything dimensioned in the 100’s of feet is “massive” > > > compared to > > > the rod antennas normally seen in WWVB use …. > > > > > > The other point being that if the antenna is some sort of large loop, > > it’s > > > going to be > > > a good long ways away from the receiver. You get both a larger signal > > > voltage and better > > > isolation ….. > > > > > > Bob > > > > > > > On Oct 8, 2020, at 11:30 PM, John C. Westmoreland, P.E. < > > > j...@westmorelandengineering.com> wrote: > > > > > > > > Hello All, > > > > > > > > Are there any design details someplace regarding these massive > > antennas? > > > > > > > > Thanks, > > > > John > > > > AJ6BC > > > > > > > > > > > > On Thu, Oct 8, 2020, 19:27 paul swed wrote: > > > > > > > >> Hello to the group. > > > >> Ray as Bob mentions you are taking a 10s of uv signal to a logic > level > > > of > > > >> maybe 4V. > > > >> If the loop is any place close to the divided down signal, it will > > > >> oscillate. It would take incredible shielding to protect the > receiver. > > > >> Thats why you often see a solution that doubles to 120 KHz and > > modifies > > > the > > > >> detectors to work at that frequency. That means hacking the radio > > > >> internally. Not fun. The other really annoy effect is that the > > doubling > > > >> slips phace due to noise and propagation. So if charting suddenly > you > > > get a > > > >> 180 degree flip. Thats messy. > > > >> The doubling solution can work. Search for carter and there are > > several > > > >> others. > > > >> But having tested and used all of the alternates and lots more on > the > > > east > > > >> coast decided they were too much trouble. You should see the box of > > > boards > > > >> I have chuckle. > > > >> For me I am very happy with the d-psk-r. Though in being above > board I > > > >> designed version 1 and Rodger and I did ve
Re: [time-nuts] WWVB Dephaser Question
John I don't think so as not sure how many have built a large antenna. Certainly any of the old wwvb receivers have details and thats pretty much what most people copy. Essentially a 3 foot copper loop with numbers of turns of wire connected together. Like 25 pair telco cable connected end to end. A large capacitor is then put across the loop to resonate it at 60 KHz. Then the preamp. Some use a FET transistor followed by a line driver transistor. Power is sent over the coax so a blocking cap and inductor. Really big is 10' by 10' using shielded 36 wire ribbon cable. ( did not use all 36 conductors it was to much L but 800 ft worth. The shield acts like the copper pipe and it must be broken so that it does not look like a shorted loop. Add the cap and preamp. In this case I built a 2 transistor NPN 2n3904 preamp. On the large antenna I use a 2 X 6 post 4ft in the ground with cement. A mast above that to support the antenna and to allow it to be turned a bit to null MSF. Thats it no real magic. Its been operational for 7 years with an occasional transistor replacement. Also coax, darn woodpeckers! Regards Paul WB8TSL On Fri, Oct 9, 2020 at 5:14 PM John C. Westmoreland, P.E. < j...@westmorelandengineering.com> wrote: > Bob, > > Thanks for the answer; but does anyone actually have a documented > specification posted for one of these 'massive' WWVB 60kHz antennas > someplace? > > Thanks. > > 73's, > John > AJ6BC > > > On Fri, Oct 9, 2020, 08:35 Bob kb8tq wrote: > > > Hi > > > > At least to me, anything dimensioned in the 100’s of feet is “massive” > > compared to > > the rod antennas normally seen in WWVB use …. > > > > The other point being that if the antenna is some sort of large loop, > it’s > > going to be > > a good long ways away from the receiver. You get both a larger signal > > voltage and better > > isolation ….. > > > > Bob > > > > > On Oct 8, 2020, at 11:30 PM, John C. Westmoreland, P.E. < > > j...@westmorelandengineering.com> wrote: > > > > > > Hello All, > > > > > > Are there any design details someplace regarding these massive > antennas? > > > > > > Thanks, > > > John > > > AJ6BC > > > > > > > > > On Thu, Oct 8, 2020, 19:27 paul swed wrote: > > > > > >> Hello to the group. > > >> Ray as Bob mentions you are taking a 10s of uv signal to a logic level > > of > > >> maybe 4V. > > >> If the loop is any place close to the divided down signal, it will > > >> oscillate. It would take incredible shielding to protect the receiver. > > >> Thats why you often see a solution that doubles to 120 KHz and > modifies > > the > > >> detectors to work at that frequency. That means hacking the radio > > >> internally. Not fun. The other really annoy effect is that the > doubling > > >> slips phace due to noise and propagation. So if charting suddenly you > > get a > > >> 180 degree flip. Thats messy. > > >> The doubling solution can work. Search for carter and there are > several > > >> others. > > >> But having tested and used all of the alternates and lots more on the > > east > > >> coast decided they were too much trouble. You should see the box of > > boards > > >> I have chuckle. > > >> For me I am very happy with the d-psk-r. Though in being above board I > > >> designed version 1 and Rodger and I did version 2. Its solid and no > > mods to > > >> any receiver. Everything has always been released to the time-nuts > > group. > > >> As they say have fun. > > >> Regards > > >> Paul. > > >> WB8TSL > > >> > > >> On Thu, Oct 8, 2020 at 5:39 PM wrote: > > >> > > >>> Bob, > > >>> > > >>> I am using a ferrite rod antenna for the receiver. No outside > antenna. > > >>> > > >>> Ray > > >>> > > >>> Original Message > > >>> Subject: Re: [time-nuts] WWVB Dephaser Question > > >>> From: Bob kb8tq > > >>> Date: Thu, October 08, 2020 12:40 pm > > >>> To: Discussion of precise time and frequency measurement > > >>> > > >>> > > >>> Hi > > >>> > > >>> A lot depends on your antenna setup. You can also swamp out the > > incoming > > >>> WWVB signal……. > > >>> > > >>> Bob > > >>
Re: [time-nuts] WWVB Dephaser Question
Hi The standard 3’ loop was not anything really exotic. There are a lot of ham / SWL articles out there showing very similar designs. One of many hits from Google: https://www.rfcafe.com/references/electronics-world/vlf-loop-antenna-january-1963-electronics-world.htm <https://www.rfcafe.com/references/electronics-world/vlf-loop-antenna-january-1963-electronics-world.htm> Bob > On Oct 9, 2020, at 8:04 PM, John C. Westmoreland, P.E. > wrote: > > Paul, > > Thanks for that detailed explanation. I've done something similar for MARS > but of course higher frequency and that was transmit also. > > I've seen the site of something similar but I think that was a 3' diameter > design; and I've looked at some of the Symmetricom schematics I've > been able to find but have yet to find a schematic of one of > the Symmetricom receive antennas. I was hoping to find the one they had > for outdoor pole mount. It's mentioned in a lot of their documents and > even some pics but no schematic details or BOM for that I've been able to > find. > > Thanks to Tim also for the response and have a good weekend! > > 73's, > John > AJ6BC > > On Fri, Oct 9, 2020, 15:24 paul swed wrote: > >> John I don't think so as not sure how many have built a large antenna. >> Certainly any of the old wwvb receivers have details and thats pretty much >> what most people copy. >> Essentially a 3 foot copper loop with numbers of turns of wire connected >> together. Like 25 pair telco cable connected end to end. A large capacitor >> is then put across the loop to resonate it at 60 KHz. Then the preamp. Some >> use a FET transistor followed by a line driver transistor. Power is sent >> over the coax so a blocking cap and inductor. >> Really big is 10' by 10' using shielded 36 wire ribbon cable. ( did not use >> all 36 conductors it was to much L but 800 ft worth. The shield acts like >> the copper pipe and it must be broken so that it does not look like a >> shorted loop. Add the cap and preamp. >> In this case I built a 2 transistor NPN 2n3904 preamp. >> On the large antenna I use a 2 X 6 post 4ft in the ground with cement. A >> mast above that to support the antenna and to allow it to be turned a bit >> to null MSF. >> Thats it no real magic. Its been operational for 7 years with an occasional >> transistor replacement. Also coax, darn woodpeckers! >> Regards >> Paul >> WB8TSL >> >> >> On Fri, Oct 9, 2020 at 5:14 PM John C. Westmoreland, P.E. < >> j...@westmorelandengineering.com> wrote: >> >>> Bob, >>> >>> Thanks for the answer; but does anyone actually have a documented >>> specification posted for one of these 'massive' WWVB 60kHz antennas >>> someplace? >>> >>> Thanks. >>> >>> 73's, >>> John >>> AJ6BC >>> >>> >>> On Fri, Oct 9, 2020, 08:35 Bob kb8tq wrote: >>> >>>> Hi >>>> >>>> At least to me, anything dimensioned in the 100’s of feet is “massive” >>>> compared to >>>> the rod antennas normally seen in WWVB use …. >>>> >>>> The other point being that if the antenna is some sort of large loop, >>> it’s >>>> going to be >>>> a good long ways away from the receiver. You get both a larger signal >>>> voltage and better >>>> isolation ….. >>>> >>>> Bob >>>> >>>>> On Oct 8, 2020, at 11:30 PM, John C. Westmoreland, P.E. < >>>> j...@westmorelandengineering.com> wrote: >>>>> >>>>> Hello All, >>>>> >>>>> Are there any design details someplace regarding these massive >>> antennas? >>>>> >>>>> Thanks, >>>>> John >>>>> AJ6BC >>>>> >>>>> >>>>> On Thu, Oct 8, 2020, 19:27 paul swed wrote: >>>>> >>>>>> Hello to the group. >>>>>> Ray as Bob mentions you are taking a 10s of uv signal to a logic >> level >>>> of >>>>>> maybe 4V. >>>>>> If the loop is any place close to the divided down signal, it will >>>>>> oscillate. It would take incredible shielding to protect the >> receiver. >>>>>> Thats why you often see a solution that doubles to 120 KHz and >>> modifies >>>> the >>>>>> detectors to work at that frequency. That means hacking the radio >>>>>> internally. Not fun. The other
Re: [time-nuts] WWVB PM Time Questions
Paul, I finally got the WWVB d-psk-r board built. I have it connected to an Arduino UNO and to my NEO-6 GPS module.The GPS module has been re-programmed to 19.2k baud and only the GPRMC NEMA message is being sent. The MC34141 is running at 12 volts and I am using 620 ohm resistors to drive the transformer center taps. I am feeding a 60 kHz sine wave into pin 8 of the transformer through a 0.47 uF non-polarized cap. I have my scope connected to pin 1 of the transformer through a 0.47 uF non-polarized cap. The 1 PPS LED connected to pin 2 of the 74HCT14 is following the 1 PPS led on the GPS board. I see the phase LED on the d-psk-r board blink at random. The LED on the UNO blinks in unison with the phase led. What should I see on the scope? I don't see anything that looks normal. No sine wave, just random pulses. I slowed the 60 kHz sine wave down to 30 Hz but still no sine wave. If I have the scan rate on the scope set to 100 msec, I would expect to see 1 second worth of sine waves. What should the output level of the 60 kHz signal from my AWG be set to? I have tried a few settings from 25 mV to 1 volt. 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] XL-DC and DC-60 manuals?
Good afternoon timenuts group! I wanted to see if anyone in this community could help me locate either a digital or hard copy of a couple manuals. A few years ago I purchased a whole bunch of timeclocks, translators, and displays from a local government surplus company. Luckily it all seemed to be operational! I’m looking in particular for the FULL manual on the Truetime (symmetricom) XL-DC. The one I can find online is incomplete, and is missing sections on the accessory cards I have installed. I’m also looking for a cleaner scan on a Truetime 60-DC unit as well. The scan online has such dark photos / low resolution that i cannot make out what items are. I’m currently doing the modification to the unit to account for the new WWVB modulation scheme, though I haven’t got it working quite yet. I am working on a (hopefully) more efficient antenna for it. I looked through the last years worth of published emails, but didn’t see anything for these two manuals. I’m not quite to the level of having my own cesium standard or similar, however my learning about GPS time, WWVB time and IRIG standards has been interesting thus far!! Thank you, Spencer KB3WYR ___ 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 SDR discussion
Hi Don - I got two of them on eBay. I got these 274056463528 . They were only $35 each with free shipping, a bargain in my opinion. Of course you can find smaller diameter ones as well. 73 - Mike Mike B. Feher, N4FS 89 Arnold Blvd. Howell NJ 07731 848-245-9115 -Original Message- From: time-nuts On Behalf Of DON MURRAY via time-nuts Sent: Thursday, August 20, 2020 8:41 PM To: time-nuts@lists.febo.com Cc: DON MURRAY Subject: Re: [time-nuts] WWVB SDR discussion Mike... Which model did you order? 73 Don W4WJ On Thursday, August 20, 2020 Mike Feher wrote: I just purchased 2 of those La Crosse 14" clocks and was totally amazed. I live on the Jersey shore on one acre surrounded by trees and about 8 miles from the ocean. After I placed batteries in the clock, it went through its initially routine which was neat in itself, and about an hour or less later the motors purred again and it went to the exact time and continues to do so. This was on the first floor of my Colonial in my office next to the computer and all sorts of other digital and switching PS noise and only about a foot off the floor. My old Junghans Mega 1000 could never do that. I have to take it upstairs with me and place it by the front (South facing) window of the master bedroom and sometime during the night it acquires and corrects if need be. Regardless, I still like my Junghans, but this new waveform is amazing. Thanks for mentioning it. Regards - Mike Mike B. Feher, N4FS 89 Arnold Blvd. Howell NJ 07731 848-245-9115 ___ 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
What may be helpful to the wwvb projects is what is always fixed. This comes out of the NIST document. Assume you have a fairly good oscillator. If it can hold within 1/2 cycle of 60 KHz (10 us) for 47 seconds you can simply sample the top minute sync word. Thats from 59-11 seconds. Always fixed. But thats a bit too easy. NIST gave us a bit more of a challenge. At 10 and 40 past the hour the slow code runs and its format is different. But has a 106 second sync word thats always fixed and always at the same location. If you have a locked oscillator then the timecode recovery is reasonable. Decoding the actual timecode is a serious pain. Good luck Paul WB8TSL On Fri, Jul 31, 2020 at 6:07 PM Poul-Henning Kamp wrote: > > Bob kb8tq writes: > > > It also *very* much depends on the stability of your local reference and > the > > stability of the ionosphere. Unless both are 'pretty darn good' a > hundred second > > integration is utter nonsense > > This is why Loran-C was so superior to any and all CW based modulations. > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > p...@freebsd.org | TCP/IP since RFC 956 > FreeBSD committer | BSD since 4.3-tahoe > Never attribute to malice what can adequately be explained by incompetence. > > ___ > time-nuts mailing list -- time-nuts@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] time-nuts Digest, Vol 193, Issue 1
I would also suggest that a simple frequency doubling if using a differential output op-amp is too hard would get one there. Something like a balanced lm/mc1496 mixer will double the input frequency if the inputs are the same. IMHO it's tempting to use software where simple (cheap! LM1496 is about $0.80/each on Digikey) analog hardware will do the trick. But it's the same math whether an analog circuit is doing it by design or if software is doing it. -T On Sat, Aug 1, 2020, 09:00 wrote: > Date: Fri, 31 Jul 2020 21:00:13 + > From: "Poul-Henning Kamp" > To: Discussion of precise time and frequency measurement > , Bob kb8tq > Subject: Re: [time-nuts] WWVB PM Time Questions > Message-ID: <85171.1596229...@critter.freebsd.dk> > Content-Type: text/plain; charset="us-ascii" > > > Bob kb8tq writes: > > >The WWVB modulation is *very* predictable. Once you have lock, > >you can guess just about every phase reversal you will see. > >[...] > >The point of this being that you *could* pre-flip the data before it > >went into a buffer. That way the buffer integration time constant > >could be quite long. > > I would just use two buffers and decide which one based on the > prediction, that way DC-offsets will not cause trouble. > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > p...@freebsd.org | TCP/IP since RFC 956 > FreeBSD committer | BSD since 4.3-tahoe > Never attribute to malice what can adequately be explained by incompetence. > ___ time-nuts mailing list -- time-nuts@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 SDR discussion
How do the small AM WWVB clocks work then. They use the 60 KHz crystal and they don't actually do anything special. In measuring those clocks they are about 2-6 hz wide. On the spectracoms the crystal is huge. Looks like a HC6 but 3" long. About 1-2 Hz wide. Using the same small crystals in BPF filters does work and does not seriously change within reasonable temperature. The one thing they do is follow the crystal with a hi Z amplifier. Just saying they work for all those atomic clocks for $10. But back to the discussion here. Need some gain and filtering. There are many good answers. John night time is cheating. I get seriously crazy levels in Boston many nights. Enjoying the thread. Regards Paul. On Tue, Aug 11, 2020 at 7:45 PM John Magliacane via time-nuts < time-nuts@lists.febo.com> wrote: > On Tuesday, August 11, 2020, 07:14:12 PM EDT, Bob kb8tq > wrote: > > > The problem with the crystal is that it has a temperature coefficient. > As a > > narrow band filter, it will have a *lot* of delay. Crystal resonance > moves > > (with temperature) and the delay changes. > > I agree. The crystal needs to be ovenized. ;-) > > That very concern led me in my design to derive nearly all my receiver > selectivity at baseband (DC) using op-amps, forgo any crystal filters, and > keep the Q of the loop antenna low. > > > 73.000 de John, KD2BD > > ___ > 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
I saw this the other day but not sure if this was answered: > 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." I interpret this as saying when you're syncing with the transmitted signal, you only do so while it's at the high amplitude. At other times you're generating the signal without external sync, and using this locally generated signal to compare with the phase of the received signal. This is similar to how the color-burst of the (now-obsolete analog) NTSC TV color signal works. I'm thinking this would all be done in software on an ARM microcontroller. The local 60kHz would be generated using a software DDS. I recall others discussed at least some aspects of this. ___ 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 teensy BPSK early experiments
John W: Regarding your Teensy WWVB receiver display issues. The Teensy does not have a source termination resistor on the SPI clock. Add a 50 Ohm resistor (value not critical, anything from 33 to 75 will work) in series with the SPI Clock signal, as physically close to the Teensy as practical. This totally cleared up all of my display issues. https://www.analog.com/media/cn/training-seminars/tutorials/MT-097.pdf Source termination resistors provide a source resistance to absorb the reflection of fast edges off the slave device input, reducing all the bouncing and wiggles on the rising and falling edges of signals, particularly important/beneficial on clock signals. --- Graham == On Wed, Nov 4, 2020 at 10:55 AM John C. Westmoreland, P.E. < j...@westmorelandengineering.com> wrote: > Paul/Chris, > > Also - in addition to the white screen, I get this sometimes after running > for a while - have you guys seen this? > > > https://user-images.githubusercontent.com/2308903/98118247-cd4c7b00-1e5f-11eb-8510-aa1ed0beba52.jpg > > 73's, > John > AJ6BC > > > 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 teensy BPSK early experiments
On 10/31/20 11:42 AM, Bob kb8tq wrote: Hi …..errr….. Can you pull the clock oscillator off the Teensy board? (Yes, the soldering iron would be involved). Will the clock input to the MCU accept something like 10 MHz? If so solder on a cable …. At that point whatever the Teeny does is locked to the 10 MHz. If that comes from one of the $3 eBay OCXO’s, steer that with a DAC output … now you have a WWVB GPSDO. Indeed, if the Teensy needs 28 MHz, then the OCXO will not be quite as cheap. Bob I've tried this - It will run just fine, but *all the UART and USB speeds change*. So, basically, the USB stops working, and you need to set your serial port to something like 112.8 * 10/28 (and it takes a bit of fiddling to get it to work right).. I sort of cheated, and switched back and forth - signal generator to 28MHz, load and debug software, start it, then switch generator to 10 MHz. And of course, all the functions that are time based, like delay() are the wrong length. One could probably figure out a relatively few patches to the Teensyduino code base that would fix all this (clock rate is a variable - you can run the teensy at multiple clock rates, even with the same 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 teensy BPSK early experiments
Hi Looking at the data sheet for the MCU, they really do want 24 MHz and that’s about it. I suspect you would do better to take your 10 MHz OCXO and run it into one of the frequency converter chips to get the 24. Then feed that into the board. One more chip, but you now don’t have a bunch of stuff to hack up. Bob > On Oct 31, 2020, at 7:17 PM, jimlux wrote: > > On 10/31/20 11:42 AM, Bob kb8tq wrote: >> Hi >> …..errr….. >> Can you pull the clock oscillator off the Teensy board? (Yes, the soldering >> iron would be involved). >> Will the clock input to the MCU accept something like 10 MHz? If so solder >> on a cable …. >> At that point whatever the Teeny does is locked to the 10 MHz. If that comes >> from one of the $3 eBay OCXO’s, steer that with a DAC output … now you >> have a WWVB GPSDO. >> Indeed, if the Teensy needs 28 MHz, then the OCXO will not be quite as cheap. >> Bob > > I've tried this - It will run just fine, but *all the UART and USB speeds > change*. So, basically, the USB stops working, and you need to set your > serial port to something like 112.8 * 10/28 (and it takes a bit of fiddling > to get it to work right).. I sort of cheated, and switched back and forth - > signal generator to 28MHz, load and debug software, start it, then switch > generator to 10 MHz. > > And of course, all the functions that are time based, like delay() are the > wrong length. > > One could probably figure out a relatively few patches to the Teensyduino > code base that would fix all this (clock rate is a variable - you can run the > teensy at multiple clock rates, even with the same 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. ___ 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] Re: Isotemp OCXO question
Internet Archive to the rescue! https://web.archive.org/web/19990506093727/http://www.isotemp.com/ocxo59.htm According to that page, the OCXO59 series is available in 5 MHz to 50 MHz... So a 1MHz version may have been an OEM version. >From a later archive of their site, here's a PDF datasheet for a 50 MHz OCXO59 series oscillator which includes a drawing for the 59 series with a pinout: http://www.isotemp.com/wp-content/uploads/2011/06/Legacy59-21.pdf On Thu, Aug 19, 2021 at 3:56 PM Robert DiRosario wrote: > I got a Trak Systems "Time Code Translator" from ebay. It's a 1U box > with large LEDs for DOY and H/M/S that translates IRIG-A to NASA-36 time > code. I plan on using the case for my WWVB clock. > > Unexpectedly it has an Isotemp OCXO in it, model OCXO59-11-2, frequency > marked as 1.000 MHz The Isotemp website is more or less dead, it has no > information on it. Does anyone have any information on this model, like > how accurate it is? It has only three wires, which I assume are power, > ground and output, with no EFC input. > > One thing that I'm sill note sure about is what to do when the receiver > is not receiving WWVB. I was thinking of using something like the > DS3231 RTC module. If this OCXO is better, I may use it. > > Thanks > > Robert > ___ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send > an email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: Isotemp OCXO question
Hi Another tidbit ….. The antennas are each actively tuned (they are *very* narrow band). As the wind blows, you can watch them adjust to the change in “shape”. Very cool ….. Bob > On Aug 21, 2021, at 4:41 PM, Poul-Henning Kamp wrote: > > > Robert DiRosario writes: > >> I really wish NIST didn't add the BPSK modulation to WWVB. Increasing >> the transmitter power would have been a lot better, but I'm sure that >> would have cost a lot more then just changing the modulation. > > One does not simply increase the transmitter power at 60kHz. > > The WWVB antennas are essentially capacitors against ground, around > 15nF, and they operate at voltages somewhere in the 30-50kV range. > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > p...@freebsd.org | TCP/IP since RFC 956 > FreeBSD committer | BSD since 4.3-tahoe > Never attribute to malice what can adequately be explained by incompetence. > ___ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an > email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: Ublox M6T -M8T
Yes, we did, and learned, that the device -- the ublox6 -- forgets the the program very fast, thus we added one arduino, which loads the program into the ublox at every new turn on. By using low output frequency -- 10kHz -- the jitter is low, at higher output frequency the jitter is getting larger, presumably because the internal clock of the ublox is a "free running " crystal oscillator. We did not do any "deep quality investigation" to the output of our 10MHz signal source output, 10 is just used as frequency calibrator for instruments. I made one phase phase comparation, --comparator one input GPS -ublox derived 60kHz the other input is wwvb 60kHz from Fort Collins Colorado, it show the typical phase change during the day of the wwvb. 73 Alexander Pummer[hard ware] + David Fannin [soft ware] On 5/28/2022 10:05 AM, R Putz via time-nuts wrote: Has anyone done anything with the Ublox GPS timing receivers? As it appears the Navman with the 10khz outputs seem to be drying up, I'm wondering about the Time Pulse 2 output being set to 10 Khz or 100 Khz. Thoughts anyone? Rich W9ENG ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-le...@lists.febo.com ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-le...@lists.febo.com
