Re: [time-nuts] WWVB information
So Doug's Spectracom WWVB receiver shows a green lock status. I didn't believe it, but he sent a photo. I then tried it here and the same thing happens to me. It's very suspicious because we know these old carrier phase WWVB receivers don't work with the enhanced WWVB broadcast format. Instead of trusting the green light I measured the 5 MHz output of the WWVB-disciplined receiver using a hp 53132A. Here's an example of 1 second readings with no antenna (no lock): 431.22296 Hz 431.22650 Hz 431.22709 Hz 431.209453 Hz 431.21235 Hz STD DEV: 0.007968 Hz You see a free-running undisciplined OCXO. Not very accurate but very stable. Then I connected the WWVB antenna. Within seconds the green lock light came on. The readings looked like: 494.676217 Hz 514.45065 Hz 466.61447 Hz 463.27949 Hz 471.40319 Hz STD DEV: 15.853246 Hz You see that the OCXO has been steered closer to 5 MHz, but the stability is horrible. Lastly, just to check the system was working, I applied a 60 kHz carrier near the antenna using a hp 3325B. The readings look like: 499.9693 Hz 500.0199 Hz 500.0202 Hz 499.9693 Hz 499.9998 Hz STD DEV: 0.02355 Hz In this case very accurate and quite stable. ADEV plot of all three runs is attached. So my conclusion is the green lock light is false. The Spectracom really isn't locking to the carrier. It's trying hard, but the new phase encoding keeps this from happening. Someone can take a look at the block diagram or schematic and explain why the circuit gets fooled into thinking there is lock when there really isn't. Look for Spectracom 8161 or 8164 on ko4bb's manual site. The one mystery is why this false green only started a week ago for Doug. If any of you have Spectracom WWVB receivers, fire then up and see what happens. I think I'll keep mine going for a few days or months and see if the false green ever goes out. /tvb ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WWVB information
Hal when I was building de-psk-ers and such I have to say I did not see the imbalance. It looked pretty solid in timing. The fact that at each minute for the first number of seconds the phase is actually fixed just before the preamble is useful. It clears out any possible buildup if it existed. Also unless I used a number of tricks like de-psk-rs and fixed carrier insertion none of my spectracoms. True Times would decode time. I am east cost US so quite far away from wwvb. I believe simple tricks by others far closer actually do work. Regards Paul WB8TSL On Fri, Apr 13, 2018 at 5:26 PM, Hal Murray wrote: > The month recently changed from 3 to 4. A while ago, the bottom digit of > the > year changed from 8 to 7. I think the out-of-phase time is shorter for a > 0 > than for a 1. Would a few more 0 bits be enough to push it into sync? > > Is there "goodness" parameter that you can monitor? It might be > interesting > to see if that correlates with day, hour, minute encoding? > > > -- > These are my opinions. I hate spam. > > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/ > mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WWVB information
The month recently changed from 3 to 4. A while ago, the bottom digit of the year changed from 8 to 7. I think the out-of-phase time is shorter for a 0 than for a 1. Would a few more 0 bits be enough to push it into sync? Is there "goodness" parameter that you can monitor? It might be interesting to see if that correlates with day, hour, minute encoding? -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WWVB information
My 8161/8164 will indicate lock as well, and I suppose they may be 'locked'. But the phase stability is so poor they may as well not be. I guess it averages out close enough to zero within the time constant to turn the LED on. It's not new behavior for my units. Phase tracking receivers are still broken. On 04/12/2018 11:07 PM, Tom Van Baak wrote: > I've been talking with Doug to better understand why his Spectracom WWVB > receiver shows the green lock indicator. This receiver should not work given > the enhanced WWVB modulation we've had since 2012. Fortunately he has chosen > not to touch anything while we ponder this. > > Meanwhile I pulled out some Spectracom gear (8164) and was able to repro his > green lock! But the 10 MHz output is very unstable so I'm pretty sure it is > not locking at all. Looking at the schematic the green indicator seems > primitive. So "lock" may not really mean it has robustly locked to the > carrier. More details to follow. > > If any of you have Spectracom WWVB 816x or 817x receivers you might want to > try them too. > > /tvb > > - Original Message - > From: "Martin VE3OAT" > To: > Cc: "Doug Millar" > Sent: Thursday, April 12, 2018 5:12 PM > Subject: Re: [time-nuts] WWVB information > > >> Hi, Doug, >> How is your 8161 doing now? Still synced properly? Should I bring my >> 8164 up from the basement? I was so disappointed when WWVB changed >> their modulation. Thanks for any encouragement. >> 73, >> ... MartinVE3OAT >> >> >> On Wed, 11 Apr 2018 16:28:41 Doug Millar wrote : >> >>> Hi, My Spectracom 8161 comparator and 8171A clock are chugging >>> right along in sync with the proper time. I have only looked at >>> the digital LED output and it is within one second of my other >>> WWVB clocks. Seems like magic. It came in synch about two >>> weeks ago and stayed there. I haven't changed anything in my >>> lab or moved the units. Antenna is still the same. >>> Pictures available. Doug K6JEY >> ___ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WWVB information
I've been talking with Doug to better understand why his Spectracom WWVB receiver shows the green lock indicator. This receiver should not work given the enhanced WWVB modulation we've had since 2012. Fortunately he has chosen not to touch anything while we ponder this. Meanwhile I pulled out some Spectracom gear (8164) and was able to repro his green lock! But the 10 MHz output is very unstable so I'm pretty sure it is not locking at all. Looking at the schematic the green indicator seems primitive. So "lock" may not really mean it has robustly locked to the carrier. More details to follow. If any of you have Spectracom WWVB 816x or 817x receivers you might want to try them too. /tvb - Original Message - From: "Martin VE3OAT" To: Cc: "Doug Millar" Sent: Thursday, April 12, 2018 5:12 PM Subject: Re: [time-nuts] WWVB information > Hi, Doug, > How is your 8161 doing now? Still synced properly? Should I bring my > 8164 up from the basement? I was so disappointed when WWVB changed > their modulation. Thanks for any encouragement. > 73, > ... MartinVE3OAT > > > On Wed, 11 Apr 2018 16:28:41 Doug Millar wrote : > > > Hi, My Spectracom 8161 comparator and 8171A clock are chugging > > right along in sync with the proper time. I have only looked at > > the digital LED output and it is within one second of my other > > WWVB clocks. Seems like magic. It came in synch about two > > weeks ago and stayed there. I haven't changed anything in my > > lab or moved the units. Antenna is still the same. > > Pictures available. Doug K6JEY > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WWVB information
Hi, Doug, How is your 8161 doing now? Still synced properly? Should I bring my 8164 up from the basement? I was so disappointed when WWVB changed their modulation. Thanks for any encouragement. 73, ... MartinVE3OAT On Wed, 11 Apr 2018 16:28:41 Doug Millar wrote : > Hi, My Spectracom 8161 comparator and 8171A clock are chugging > right along in sync with the proper time. I have only looked at > the digital LED output and it is within one second of my other > WWVB clocks. Seems like magic. It came in synch about two > weeks ago and stayed there. I haven't changed anything in my > lab or moved the units. Antenna is still the same. > Pictures available. Doug K6JEY ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] WWVB information
Hi, My Spectracom 8161 comparator and 8171A clock are chugging right along in sync with the proper time. I have only looked at the digital LED output and it is within one second of my other WWVB clocks. Seems like magic. It came in synch about two weeks ago and stayed there. I haven't changed anything in my lab or moved the units. Antenna is still the same. Pictures available. Doug K6JEY ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
