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There are several cheap WWVB receivers available.? Has anyone successfully implemented WWVB as a 1pps time source rather than GPS for QRP Labs kits?? How did you do it and what are the pros and cons between WWVB and GPS?? One that comes to my mind is a clear view of the sky is not required with the WWVB 60kHz signal.? A disadvantage might be potential interference to 60kHz from LED light dimmers and such.? Which is more reliable?? Maybe have one automatically back up the other?
-Jerry AC5JM
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Have not tried this and don't know if it's even possible. But even if it is, in most areas of NA, it's only receivable at night for a few hours.?
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73, Dan? NM3A
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Really?? I didn't know that.? I have always been able to hear the 60 kHz signal 24/7 in northeast Oklahoma 600 miles away.? I thought WWVB was designed to cover at least the lower 48 states of US the same.? The only situation that I have experienced when it cannot be heard is when there is local interference covering it up.? I have literally never not heard it when I tuned it in with a decent receiver with almost any length of wire for an antenna.? Maybe 600 miles is close enough that it works all the time??
-Jerry AC5JM
On Monday, September 18, 2023 at 05:34:09 AM CDT, Daniel Walter via groups.io <nm3a@...> wrote:
Have not tried this and don't know if it's even possible. But even if it is, in most areas of NA, it's only receivable at night for a few hours.?
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73, Dan? NM3A
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I live in the Philly area. I can only hear it sporadically?at night. Indeed, I have a few wrist watches with WWV RX's in them . They try to sync at 1,2,3 & 4AM. This night time reception appears to be a "thing". I have many clocks that only try at night.
Maybe 600 miles is close enough for the groundwave??
Used to be that you could buy a tuned/resonant WWVB antenna from a guy in CT via ebay. He's got a few Youtubes about tuned antennas. In his video's?he's always able to receive WWVB on 60KHz with one of his antennas.
Mark/NI2O
Really?? I didn't know that.? I have always been able to hear the 60 kHz signal 24/7 in northeast Oklahoma 600 miles away.? I thought WWVB was designed to cover at least the lower 48 states of US the same.? The only situation that I have experienced when it cannot be heard is when there is local interference covering it up.? I have literally never not heard it when I tuned it in with a decent receiver with almost any length of wire for an antenna.? Maybe 600 miles is close enough that it works all the time??
-Jerry AC5JM
On Monday, September 18, 2023 at 05:34:09 AM CDT, Daniel Walter via <nm3a= [email protected]> wrote:
Have not tried this and don't know if it's even possible. But even if it is, in most areas of NA, it's only receivable at night for a few hours.?
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73, Dan? NM3A
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I live about 600 miles away from WWVB also (in Idaho). My wristwatch WWVB receiver also only tries at night. If I force it to try during the day, it is hit or miss. I can only assume that my wristwatch radio has marginal sensitivity, at best, for good 60kHz reception. Well, it’s a radio stuffed into a tiny wristwatch package, so that’s not surprising. :) I also have a wall clock that receives WWVB but I don’t know when it tries to sync and the seconds are always right on (I’ve never had to mess with it).
A company called Canaduino still sells a WWVB receiver module. You can find them on Amazon for about $13 or so. Or, some people have luck harvesting the module out of cheap used clocks if you know what to look for.
You would have to hook up the Canaduino module to a Arduino or similar to try and decode the WWVB signal into a 1 PPS. I don’t think you’ll get it directly from the module. And I’m not so sure it would be accurate enough to use for calibration (like a GOS 1 PPS pulse) but maybe?
73, Gregg
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A big problem with VLF time standards is their keying is accurate to around 1mS.? It depends on things like the tuning and matching components and antenna used at the transmitter.? I believe that the 60kHz transmitter here in UK (MSF) uses a "crowbar" across the antenna to rapidly quench the transmitted signal to ensure that the keyed waveform drops within 1mS of the second epoch.? If you were to use such a signal for synchronizing a standard oscillator, you would need to average the keying pulses over a considerable time period.? Then you might run into the diurnal variation in VLF signal propagation as the ionosphere changes between day and night.? Compare with a GNSS receiver which typically has a jitter in the 1 second pulse of 10 to 20nS and a much more stable propagation path.
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Peter Lee
G3SPL
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Back in the dawn of time we had a WWVB receiver that we checked our lab standard with, and WWVB was only stable overnight in MA. ?I'd have to say if you can get a good (ground wave) signal 24x7 you might be able to lock a local standard to it, but otherwise you might have to watch the reference and tweak your standard occasionally, as we did.
I'd use a GPSDO, those are easy, cheap, and usually pretty solid.
73, Willie N1JBJ
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On Sep 17, 2023, at 5:27 PM, Jerry Moyer via groups.io <ac5jm@...> wrote:
There are several cheap WWVB receivers available.? Has anyone successfully implemented WWVB as a 1pps time source rather than GPS for QRP Labs kits?? How did you do it and what are the pros and cons between WWVB and GPS?? One that comes to my mind is a clear view of the sky is not required with the WWVB 60kHz signal.? A disadvantage might be potential interference to 60kHz from LED light dimmers and such.? Which is more reliable?? Maybe have one automatically back up the other?
-Jerry AC5JM
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I would think that the accuracy of WWVB would be the absolute most accurate time source since it is controlled by a Cesium clock at the National Bureau of Standards itself. ?It is the primary source for all US time standards . ?There could be a slight amount of propagation delay I suppose but there also would be from a satellite.
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On Sep 18, 2023, at 10:00 AM, William Smith <w_smith@...> wrote:
? Back in the dawn of time we had a WWVB receiver that we checked our lab standard with, and WWVB was only stable overnight in MA. ?I'd have to say if you can get a good (ground wave) signal 24x7 you might be able to lock a local standard to it, but otherwise you might have to watch the reference and tweak your standard occasionally, as we did.
I'd use a GPSDO, those are easy, cheap, and usually pretty solid.
73, Willie N1JBJ On Sep 17, 2023, at 5:27 PM, Jerry Moyer via groups.io <ac5jm@...> wrote:
There are several cheap WWVB receivers available.? Has anyone successfully implemented WWVB as a 1pps time source rather than GPS for QRP Labs kits?? How did you do it and what are the pros and cons between WWVB and GPS?? One that comes to my mind is a clear view of the sky is not required with the WWVB 60kHz signal.? A disadvantage might be potential interference to 60kHz from LED light dimmers and such.? Which is more reliable?? Maybe have one automatically back up the other?
-Jerry AC5JM
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There's an atomic clock in each GPS satellite, and they work together to null out the propagation delay, so the 1PPS signal is way closer than the timecode from WWVB.
73, Willie N1JBJ
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On Sep 18, 2023, at 12:37 PM, Jerry Moyer via groups.io <ac5jm@...> wrote:
I would think that the accuracy of WWVB would be the absolute most accurate time source since it is controlled by a Cesium clock at the National Bureau of Standards itself. ?It is the primary source for all US time standards . ?There could be a slight amount of propagation delay I suppose but there also would be from a satellite.
-Jerry
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The propagation delay depends of course upon the distance from the transmitter in Fort Collins. About 6.3mS for me in London Ontario.
The way a GPS system works, each satellite transmits its orbit and time, and the receiver takes a number of satellite signals, all arriving at slightly different times due to their different propagation distances, works out the receiver position, and then calculates a time correction. ?Modern receivers get it right to within a handful of nanoseconds.
You can compare the GPS PPS with the arrival time of the WWV and WWVB signals and watch the ionosphere move.
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On Sep 18, 2023, at 12:37, Jerry Moyer via groups.io <ac5jm@...> wrote:
? I would think that the accuracy of WWVB would be the absolute most accurate time source since it is controlled by a Cesium clock at the National Bureau of Standards itself. ?It is the primary source for all US time standards . ?There could be a slight amount of propagation delay I suppose but there also would be from a satellite.
-Jerry On Sep 18, 2023, at 10:00 AM, William Smith <w_smith@...> wrote:
? Back in the dawn of time we had a WWVB receiver that we checked our lab standard with, and WWVB was only stable overnight in MA. ?I'd have to say if you can get a good (ground wave) signal 24x7 you might be able to lock a local standard to it, but otherwise you might have to watch the reference and tweak your standard occasionally, as we did.
I'd use a GPSDO, those are easy, cheap, and usually pretty solid.
73, Willie N1JBJ On Sep 17, 2023, at 5:27 PM, Jerry Moyer via groups.io <ac5jm@...> wrote:
There are several cheap WWVB receivers available.? Has anyone successfully implemented WWVB as a 1pps time source rather than GPS for QRP Labs kits?? How did you do it and what are the pros and cons between WWVB and GPS?? One that comes to my mind is a clear view of the sky is not required with the WWVB 60kHz signal.? A disadvantage might be potential interference to 60kHz from LED light dimmers and such.? Which is more reliable?? Maybe have one automatically back up the other?
-Jerry AC5JM
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Gregg, your watch being so small is only part of the issue. WWVB is broadcasting at 60KHz which propagates best at night. WWW (Colorado) and WWVH (Hawaii) use?the?HF bands on multiple frequencies so that they can be heard during the?day as well.? 73, kevin kc6pob
I live about 600 miles away from WWVB also (in Idaho). My wristwatch WWVB receiver also only tries at night. If I force it to try during the day, it is hit or miss. I can only assume that my wristwatch radio has marginal sensitivity, at best, for good 60kHz reception. Well, it’s a radio stuffed into a tiny wristwatch package, so that’s not surprising. :) I also have a wall clock that receives WWVB but I don’t know when it tries to sync and the seconds are always right on (I’ve never had to mess with it).
A company called Canaduino still sells a WWVB receiver module. You can find them on Amazon for about $13 or so. Or, some people have luck harvesting the module out of cheap used clocks if you know what to look for.
You would have to hook up the Canaduino module to a Arduino or similar to try and decode the WWVB signal into a 1 PPS. I don’t think you’ll get it directly from the module. And I’m not so sure it would be accurate enough to use for calibration (like a GOS 1 PPS pulse) but maybe?
73, Gregg
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I stand corrected. After reviewing stuff, I see the signal IS available for most of NA all day long. However, near the east coast it is weaker and apparently there is a competing signal from UK (MSF) on the same frequency, so in the NE USA it's only reliable at night. Apparently, most of the so-called atomic clocks only look for the signal at night, probably for that reason.?
as far as accuracy, the original accurate sync no longer works since 2012, but a phase shift was introduced then and receivers designed for that can get extremely time syncs. I have no idea where you can get those receivers though. Using that, and compensating for the propagation delay, supposedly it is accurate to 10^-12 sec.?
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73, Dan? NM3A
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I’ve lived in Michigan, Ohio, California, Texas, and Georgia and have never been able to hear it.? Never tried in the middle of the night and I’m not likely start trying now! ? Mike WM4B ?
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From: [email protected] < [email protected]> On Behalf Of Jerry Moyer via groups.io Sent: Monday, September 18, 2023 9:30 AM To: [email protected]Subject: Re: [QRPLabs] WWVB 1PPS clock? ? Really?? I didn't know that.? I have always been able to hear the 60 kHz signal 24/7 in northeast Oklahoma 600 miles away.? I thought WWVB was designed to cover at least the lower 48 states of US the same.? The only situation that I have experienced when it cannot be heard is when there is local interference covering it up.? I have literally never not heard it when I tuned it in with a decent receiver with almost any length of wire for an antenna.? Maybe 600 miles is close enough that it works all the time?? On Monday, September 18, 2023 at 05:34:09 AM CDT, Daniel Walter via groups.io <nm3a@...> wrote: Have not tried this and don't know if it's even possible. But even if it is, in most areas of NA, it's only receivable at night for a few hours.?
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73, Dan? NM3A
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You certainly COULD, and depending on the quality of the WWVB signal you get it could be as good as GPS or a good deal worse at the receiving end.? ...? and it will vary by time of day etc and that error may not be immediately obvious either.
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GPS however - given a decent antenna and clear view of the sky - will be spot on anytime (and in the QCX etc context will also set the clock and Maidenhead locator.
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I still have a lovingly designed and built 198 KHz receiver that I used to 'double check'? my GPS frequency standard's accuracy but it too suffers from propagation issues at times and that station is apparently about to be shut down anyway? (thanks BBC!)?
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I have a clock that uses WWVB for time sync and it almost always shows that it is connected here in Illinois.
Gary
W9TD
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Most of those clocks show an icon that shows if the clock synced with WWVB at sometime in the past day or maybe longer. The icon doesn't necessarily mean it is currently receiving the signal.?
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73, Dan? NM3A
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Mark Phillips
Mike Besemer - WM4B
Bruce Akhurst
Gary W9TD