Re: [time-nuts] HP5061 Cesium ion pump question
Thanks very much for this info Corby. It explains the behaviour of my spare 5061A perfectly. It also raises the question of what I could do with the spare tube I have. I can connect a +3500V supply to the ion pump but that won't do anything about any gas molecules adsorbed onto the filaments as you described. Is it worth powering up the filaments to get rid of them or can that be left for some indefinite time in the future when the tube could be reinstalled in a 5061A? Morris --- Date: Wed, 2 Dec 2020 11:06:22 -0800 From: To: time-nuts@lists.febo.com Subject: [time-nuts] HP5061 Cesium ion pump question The gettering in the tube is only for capturing any stray Cesium atoms that don't get caught in the main gettering patch. If the gettering fails or gets too loaded up then the Cesium background level will get too high causing poor SN. The ion pump is for any gases. When a tube is off for extended times any gas atoms lingering or leaking slowly into the tube than happen to impinge on either the mass Spectrometer filament or the Cs oven filaments get capture by the filaments. They function as excellent getters! (this even if the ion pump is on) Now this is not by design but results in the filaments being "loaded" with the gas atoms. Then when you turn the tube on the filaments light up and expell a burst of gas. This of coarse causes the ion pump current to rise and trips off the filaments, Once the ion pump removes the burst the cycle repeats until the filaments have expelled the trapped gases. Then the ion pump can handle the load and pump the tube down completely. Cheers, Corby * ___ 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] Trimble Thunderbolt has No satellites
Jan - Your Posted Display (Thunderbolt Monitor) shows that NO GPS Signals are being Received / Data Output to your Computer. — CHECK your Antenna, Coax, and Connectors : Your problem is appears to be there. Use a SECOND +5 Volt GPS Antenna ... to Verify Thunderbolt is Not at Fault. CAUTION: NEWER GPS Antennas are often ONLY +3.3 Volt ... and could damage pre-amplifier within GPS antenna or Thunderbolt. — I have a Trimble Thunderbolt (RED), Surplus from a 911 Call Center when 2019 WNRO Event occurred. Running very well with Lady Heather version 6.14 Beta. ** IF you are using a Serial to USB converter ... Latest Windows 10 has a BUG for USB 3.0 hubs. Microsoft promises “fix” ASAP (likely next 4 weeks). ** == Week Number RollOver (WNRO) is a known GPS issue, NOT corrected by MANY GPS manufacturers (firmware oversight, planned obsolescence, etc.) https://www.trimble.com/WNRO/ The First GPS WNRO event occurred in 1999. The Second WNRO occurred on April 6, 2019, at GPS Midnight. — The Trimble Thunderbolt (RED and older OEM models) is NOT Upgradable by Trimble. http://www.leapsecond.com/pages/tbolt/Thunderbolt-2003-11.pdf Trimble sells the Thunderbolt-E (BLUE label) as the replacement. https://www.trimble.com/Timing/thunderbolt-e.aspx — LADY HEATHER (LH) version 6.xx BETA for Windows corrects the WNRO date that LH displays. Trimble Thunderbolt still outputs (serial data) the incorrect date. Mark Sims (texaspyro) posted the Link and Instructions on EEVBLOG (February 22, 2018) https://www.eevblog.com/forum/metrology/lady-heather-v6-beta-for-windows-exe/msg1434005/#msg1434005 === greg, w9gb chicago === Date: Thu, 3 Dec 2020 08:51:43 +0100 From: To: Subject: [time-nuts] Trimble Thunderbolt has No satellites Hello, I am new to this, so advice is welcome. I had a Trimble Thunderbolt running the whole summer and when checking today, it seems I lost satellite tracking. But I don't know what is wrong or how to diagnose it. I tried a power cycle and factory reset. In the Thunderbolt Monitor (Application): 1. All Alarms are Green. 2. All Signal levels (SV and AMU) are empty with a question mark. 3. I seem to get an accurate time. 4. The Timing outputs seem be ok and quite stable, nothing compared to a first start. 5. I get a GPS position. 6. RCVR mode = (7) Overdetermined Clock (time) 7. GPS status = (0) Doing fixes It seems the time is getting in, but no satellite fixes. I checked the bias of the antenna, it was about 5 volts. What could be wrong? Or how could I check it further? The GPS antenna is about 5 meters from the house but only about 50cm from the ground. Could this be seasonal? Is my house blocking the signal this time of year? I added some screenshots on the EEVBlog forum: https://www.eevblog.com/forum/metrology/trimble-thunderbolt-nu-satellites-128752/new/#new I'm a bit lost, to be frank. Thank you. -Jan ___ 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] trimble thunderbolt has no satellites
Using another USB to serial cable fixed it! Now I am using an USB 2 port and not the integrated serial port of my docking station (internally connected to USB 3.0) Jezus... go figure... ___ 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] trimble thunderbolt has no satellites
On 2020-12-03 01:51, jan.catry...@gmail.com wrote: I had a Trimble thunderbolt running the whole summer and when checking today, it seems I lost satellite tracking. It is worth trying a different antenna. The lack of antenna alarm in the monitor program indicates that the amplifier in the antenna has not failed completely, at least not in a way that causes it to stop drawing current, or draw too much current, but lack of satellites tracked would seem to indicate something in the front end RF chain. Antenna is the easiest to check. If not the antenna then possibly the front end RF amplifier was damaged, but I've never looked into how difficult that would be to change. Hopefully just a damaged antenna from a summer thunderstorm or similar. -- Chris Caudle ___ 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] HP5065a cfield issue
Hi Try rotating the 5065 180 degrees and see if the frequency shifts. If it shifts more than a little, you have something local that is magnetized. Bob > On Dec 3, 2020, at 1:23 PM, paul swed wrote: > > Well Bob what an unusual comment about large magnetic fields. It just so > happens that maybe I actually had one about 8 weeks ago. Its called a > lightning strike about 60' away. Just found the actual 100' pine tree 2 > days ago. I had been looking but it sounded like it hit in the opposite > direction. > The strike did wipe out a nvr and copper networking. But it did not seem to > impact the the cesiums or many many other pieces of equipment. > The 5065 is still super stable. > Regards > Paul > > > > On Thu, Dec 3, 2020 at 11:57 AM Bob kb8tq wrote: > >> Hi >> >> I don’t believe that the quantum transitions are sensitive enough to minor >> temperature >> shifts to account for a 1 or 2 ppb sort of shift….. Magnetic field, ( >> giant magnetic play toy >> moved next to Rb … ) yes that will do the trick, but temperature … tough >> to do … >> >> Everything I can find that documents what’s what is behind this or that >> pay wall. I’m >> not $80 interested enough in the answer :) >> >> Bob >> >>> On Dec 3, 2020, at 10:51 AM, Poul-Henning Kamp >> wrote: >>> >>> >>> >>> Could it be the thermostat circuits have shifted so you run at a >>> different temperature now ? >>> >>> -- >>> 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. ___ 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] HP5065a cfield issue
paul swed writes: Change the polarity of the C-field by swapping the two wires ? If that changes your frequency, you know you have a residual magnetic field pushing the frequency of your atoms. But be aware that the frequency shift does not tell you the magnitude of the residual field, because it may have a direction different from the C-field solenoid. That also means that even with no frequency shift, a magnetic field could still be present if it is perfectly orthogonal to the C-field solenoid. -- 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] HP5065a cfield issue
Paul: You can have some fun with this: A vertical line current flow in the neighborhood of 30,000 amperes, pulse risetime on the order of 2-5 microsec, fall time about 40. Kind of a giant magnetic play toy. Don Latham On 2020-12-03 11:23, paul swed wrote: Well Bob what an unusual comment about large magnetic fields. It just so happens that maybe I actually had one about 8 weeks ago. Its called a lightning strike about 60' away. Just found the actual 100' pine tree 2 days ago. I had been looking but it sounded like it hit in the opposite direction. The strike did wipe out a nvr and copper networking. But it did not seem to impact the the cesiums or many many other pieces of equipment. The 5065 is still super stable. Regards Paul On Thu, Dec 3, 2020 at 11:57 AM Bob kb8tq wrote: Hi I don’t believe that the quantum transitions are sensitive enough to minor temperature shifts to account for a 1 or 2 ppb sort of shift….. Magnetic field, ( giant magnetic play toy moved next to Rb … ) yes that will do the trick, but temperature … tough to do … Everything I can find that documents what’s what is behind this or that pay wall. I’m not $80 interested enough in the answer :) Bob > On Dec 3, 2020, at 10:51 AM, Poul-Henning Kamp wrote: > > > > Could it be the thermostat circuits have shifted so you run at a > different temperature now ? > > -- > 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. -- Dr. Don Latham AJ7LL PO Box 404, Frenchtown, MT, 59834 VOX: 406-626-4304 ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] HP5065a cfield issue
The 5065 is 2.3 E-11. Thats far more normal. Regards Paul. On Thu, Dec 3, 2020 at 1:27 PM paul swed wrote: > Please ignore the drift rate numbers I shared they are wrong. > Will get a new set of numbers that I expect will be normal. > > On Thu, Dec 3, 2020 at 1:23 PM paul swed wrote: > >> Well Bob what an unusual comment about large magnetic fields. It just so >> happens that maybe I actually had one about 8 weeks ago. Its called a >> lightning strike about 60' away. Just found the actual 100' pine tree 2 >> days ago. I had been looking but it sounded like it hit in the opposite >> direction. >> The strike did wipe out a nvr and copper networking. But it did not seem >> to impact the the cesiums or many many other pieces of equipment. >> The 5065 is still super stable. >> Regards >> Paul >> >> >> >> On Thu, Dec 3, 2020 at 11:57 AM Bob kb8tq wrote: >> >>> Hi >>> >>> I don’t believe that the quantum transitions are sensitive enough to >>> minor temperature >>> shifts to account for a 1 or 2 ppb sort of shift….. Magnetic field, ( >>> giant magnetic play toy >>> moved next to Rb … ) yes that will do the trick, but temperature … >>> tough to do … >>> >>> Everything I can find that documents what’s what is behind this or that >>> pay wall. I’m >>> not $80 interested enough in the answer :) >>> >>> Bob >>> >>> > On Dec 3, 2020, at 10:51 AM, Poul-Henning Kamp >>> wrote: >>> > >>> > >>> > >>> > Could it be the thermostat circuits have shifted so you run at a >>> > different temperature now ? >>> > >>> > -- >>> > 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] HP5065a cfield issue
Please ignore the drift rate numbers I shared they are wrong. Will get a new set of numbers that I expect will be normal. On Thu, Dec 3, 2020 at 1:23 PM paul swed wrote: > Well Bob what an unusual comment about large magnetic fields. It just so > happens that maybe I actually had one about 8 weeks ago. Its called a > lightning strike about 60' away. Just found the actual 100' pine tree 2 > days ago. I had been looking but it sounded like it hit in the opposite > direction. > The strike did wipe out a nvr and copper networking. But it did not seem > to impact the the cesiums or many many other pieces of equipment. > The 5065 is still super stable. > Regards > Paul > > > > On Thu, Dec 3, 2020 at 11:57 AM Bob kb8tq wrote: > >> Hi >> >> I don’t believe that the quantum transitions are sensitive enough to >> minor temperature >> shifts to account for a 1 or 2 ppb sort of shift….. Magnetic field, ( >> giant magnetic play toy >> moved next to Rb … ) yes that will do the trick, but temperature … tough >> to do … >> >> Everything I can find that documents what’s what is behind this or that >> pay wall. I’m >> not $80 interested enough in the answer :) >> >> Bob >> >> > On Dec 3, 2020, at 10:51 AM, Poul-Henning Kamp >> wrote: >> > >> > >> > >> > Could it be the thermostat circuits have shifted so you run at a >> > different temperature now ? >> > >> > -- >> > 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] HP5065a cfield issue
Well Bob what an unusual comment about large magnetic fields. It just so happens that maybe I actually had one about 8 weeks ago. Its called a lightning strike about 60' away. Just found the actual 100' pine tree 2 days ago. I had been looking but it sounded like it hit in the opposite direction. The strike did wipe out a nvr and copper networking. But it did not seem to impact the the cesiums or many many other pieces of equipment. The 5065 is still super stable. Regards Paul On Thu, Dec 3, 2020 at 11:57 AM Bob kb8tq wrote: > Hi > > I don’t believe that the quantum transitions are sensitive enough to minor > temperature > shifts to account for a 1 or 2 ppb sort of shift….. Magnetic field, ( > giant magnetic play toy > moved next to Rb … ) yes that will do the trick, but temperature … tough > to do … > > Everything I can find that documents what’s what is behind this or that > pay wall. I’m > not $80 interested enough in the answer :) > > Bob > > > On Dec 3, 2020, at 10:51 AM, Poul-Henning Kamp > wrote: > > > > > > > > Could it be the thermostat circuits have shifted so you run at a > > different temperature now ? > > > > -- > > 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] HP5065a cfield issue
Just rechecked everything as the system seems far to good to be true. Yet everything is actually correct. It is drifting fast compared to the TBolt. But its very small. I am still in the 1.5-1.7ns range after 2 hours and 43 minutes. I believe by calculation that 1.5 E-13. That makes no sense. Simply taking 1.5ns/9,780 seconds. Regards Paul. On Thu, Dec 3, 2020 at 11:15 AM paul swed wrote: > Hi Poul > At least the front panel meter readings do not show any changes. Perhaps > an increase of 1 count sub tick mark changes that I would attribute to > typical drift. Looking over years the readings are consistent. Will say the > second harmonic level is high at 55. But its been that high in the past and > at other times as low as 28. But on average 48-50. > Regards > Paul > > On Thu, Dec 3, 2020 at 10:51 AM Poul-Henning Kamp > wrote: > >> >> >> Could it be the thermostat circuits have shifted so you run at a >> different temperature now ? >> >> -- >> 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] HP5065a cfield issue
Hi I don’t believe that the quantum transitions are sensitive enough to minor temperature shifts to account for a 1 or 2 ppb sort of shift….. Magnetic field, ( giant magnetic play toy moved next to Rb … ) yes that will do the trick, but temperature … tough to do … Everything I can find that documents what’s what is behind this or that pay wall. I’m not $80 interested enough in the answer :) Bob > On Dec 3, 2020, at 10:51 AM, Poul-Henning Kamp wrote: > > > > Could it be the thermostat circuits have shifted so you run at a > different temperature now ? > > -- > 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] HP5065a cfield issue
Hi Poul At least the front panel meter readings do not show any changes. Perhaps an increase of 1 count sub tick mark changes that I would attribute to typical drift. Looking over years the readings are consistent. Will say the second harmonic level is high at 55. But its been that high in the past and at other times as low as 28. But on average 48-50. Regards Paul On Thu, Dec 3, 2020 at 10:51 AM Poul-Henning Kamp wrote: > > > Could it be the thermostat circuits have shifted so you run at a > different temperature now ? > > -- > 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] HP5065a cfield issue
Could it be the thermostat circuits have shifted so you run at a different temperature now ? -- 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] HP5065a cfield issue
Well the 5065 has been cooking overnight. Started a test this morning a scope Tbolt channel A and 5065 chnl B 5ns/div. Its +1.5 ns after 1 hour and 22 minutes. Much as I have been used to in the past. Have to get excel out to see what that all means. That in know way explains why it essentially jumped. Really scratching my head on that and even how I can troubleshoot it. Voltage supply and such all are very good and clean. May have to just log all of this, shut the 5065 down and see what happens when I turn the unit back on after a week. Regards Paul On Wed, Dec 2, 2020 at 10:46 PM paul swed wrote: > For everyone when the cfield pot is at 0.0 its 2.5ma and at 9.9 its 6.38ma. > The jump is over 4 major divisions of the cfield pot and I still did not > match the reference.. > So looking at the synth chart on page 3-9 started to see how far it had > gone. > Tube says the switch should be 8714 or -240 E-10 the switch setting that > works well is 7698 and that represents -230 E-10. Thats quite a change. But > the Cfield matches the reference at 3.5 and that takes 6 min and 53 seconds > to move 5ns. Could do better but ran out of time tonight) Its still > slightly fast. The green cont op lights and stays lit. Some of the chart > settings do not light the con op light. Will see if the unit actually stays > stable overnight or does it speed up or slow down. > If it does thats going to be tough to find. > Thanks everyone so far for your help. > Paul. > > On Wed, Dec 2, 2020 at 7:51 PM Bob kb8tq wrote: > >> Hi >> >> Ok, if that still turns out to be correct … that’s just about 2 ppb. ( >> 1.6667…). >> To do that with the C field, you would need to make a *major* change. It’s >> essentially the whole range of the pot. You already know that it’s off in >> the >> direction of needing more counts on the dial. I *think* the current is >> lowest >> at that end, but I could easily be wrong. Either you need zero current or >> 2X normal. Either way that should be easy to spot. >> >> Bob >> >> >> >> > On Dec 2, 2020, at 2:59 PM, paul swed wrote: >> > >> > Yes absolutely it can go back and it is the same offset. I can get real >> > numbers from memory 3 seconds for 5ns drift and the units slow. Will >> > confirm and reshare. >> > Regards >> > Paul. >> > >> > >> > On Wed, Dec 2, 2020 at 2:52 PM Bob kb8tq wrote: >> > >> >> Hi >> >> >> >> Just double checking….. Are we still after a change went past 1/3 of >> the >> >> pot range? >> >> >> >> Can we get the pot back to the original location and measure the >> frequency >> >> offset >> >> (even if only in a crude fashion)? >> >> >> >> Best guess is still that this should be a ppb or more of shift. If it’s >> >> down in the >> >> 4x10^-11 range then indeed, there’s something off in the C Field setup. >> >> >> >> Bob >> >> >> >>> On Dec 2, 2020, at 2:03 PM, paul swed wrote: >> >>> >> >>> Corby will check. Though in looking at the cfield circuits it does >> appear >> >>> all to be correct. Its some other odd offset that has crept in. >> >>> Thanks >> >>> >> >>> On Wed, Dec 2, 2020 at 1:56 PM wrote: >> >>> >> Paul, >> >> One other thing to check. >> >> Put a DC coupled scope on the C-field pot wiper and rotate the pot >> back >> and forth. >> >> Make sure there are no jumps or noise. >> >> Sometimes the pot gets noisy in a section. >> >> Rotating it back and forth across the bad sections will usually >> clean it >> up. >> >> Cheers, >> >> Corby >> >> >> ___ >> 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
[time-nuts] trimble thunderbolt has no satellites
Hello, I am new to this, so advice is welcome. I had a Trimble thunderbolt running the whole summer and when checking today, it seems I lost satellite tracking. But I don't know what is wrong or how to diagnose it. I tried a power cycle and factory reset. In the thunderbolt monitor 1. all alarms are green. 2. signal levels (SV and AMU) are all empty with a question mark. 3. I seem to get an accurate time. 4. the timing outputs seem be ok and quite stable, nothing compared to a first start. 5. I get a GPS position. 6. RCVR mode = (7) Overdet. Clock (time) 7. GPS status = (0) Doing fixes It seems the time is getting in, but no satellite fixes. I checked the bias of the antenna, it was about 5 volts. What could be wrong? Or how could I check it further? The GPS antenna is about 5 meters from the house but only about 50cm from the ground. Could this be seasonal? Is my house blocking the signal this time of year? I added some screenshots on the EEVBlog forum: https://www.eevblog.com/forum/metrology/trimble-thunderbolt-nu-satellites-12 8752/new/#new I'm a bit lost to be frank. Thank 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.
