Re: [time-nuts] Thunderbolt E failing
I received one of these thunderbolts. It seems to work (currently handicapped by an inadequate antenna) and is labelled P/N 48050-61 D/C 0331 on the outside. The firmware is 3.00 and the OCXO labelled 37265 10.00 MHz B11859-17495 0310. On Sat, Sep 12, 2020 at 10:43 PM Adrian Godwin wrote: > Thanks! > > The one I've seen pictured most often comes in a (I think) slightly lower > gold-coloured (alocromed) case. > e.g. http://www.sydneystormcity.com/TrimbleThunderboltGPS.jpg > Is that any different ? > > I did order the one from my link so will report on any markings. The > vendor mentioned part 48050-61 but as you say, that seems to be common to > all of them. > > > On Sat, Sep 12, 2020 at 10:14 PM Bob kb8tq wrote: > >> Hi >> >> The unit your link points to *is* the “classic” TBolt that showed up in >> volume a bit >> over a decade ago. That one is packaged with a (noisy) switching power >> supply. >> >> There is no easy way to tell what era it is from. Indeed if it is from >> the 1990’s the >> OCXO will not be quite as good as what’s in one from > 2002. Since the >> unit normally >> operates locked, that’s not a real big deal. >> >> Since Trimble used “Thunderbolt” for a whole line of parts *and* was not >> very good >> at labeling devices, there is no easy way to refer to this or that >> specific device. That >> makes coming up with a list of units a bit hard. For example - what’s the >> model number >> of the part in that eBay listing ? ( No I don’t know either …. :) ). >> >> Bob >> >> > On Sep 12, 2020, at 12:28 PM, Adrian Godwin >> wrote: >> > >> > I've been looking for a thunderbolt for a while, mostly because they're >> > such a benchmark within this group. I missed the period when they were >> more >> > commonly available and have mostly found ones that were a lot more >> > expensive, or had a large delivery cost due to being in Australia. >> > >> > Some cheaper examples turned up on UK ebay. These aren't the classic >> > time-nuts ones but presumably look fairly similar to Lady Heather. >> > >> > https://www.ebay.co.uk/itm/154078750287 >> > >> > I haven't been able to find a comparison of the various thunderbolt >> models. >> > Is there a description somewhere ? I've found a few hints about this >> one - >> > I think it's a single 48V supply and possibly a lower-quality OCXO. >> > >> > On Sat, Sep 12, 2020 at 5:14 PM Kevin Schuchmann >> wrote: >> > >> >> Matthias, >> >>You are correct, having spent hours looking at all the stable areas >> >> and cooling and heating the gpsdo I find that when it reports that it >> is >> >> 116.25 F then it is stable. >> >> So now I guess I need to figure out why it is so picky. I will measure >> >> the current draw from a cold start and see if I see the oven warming up >> >> and then stabilizing and then heat and cool it and see how it reacts, >> >> and also look at the electronics and see if an area is overly sensitive >> >> to temperature. >> >> >> >> Thanks >> >> Kevin >> >> >> >> >> >> On 9/11/2020 2:26 AM, Matthias Welwarsky wrote: >> >>> On Freitag, 11. September 2020 01:08:09 CEST Kevin Schuchmann wrote: >> Guess my image didn't make it, I will add it as an attachment this >> time. >> >>> The temperature curve seems to show some correlation to what is >> >> happening with >> >>> the DAC. Seems that the DAC and OSC jumps are mostly during periods of >> >> some >> >>> thermal perturbation. >> >>> >> >>> Regards, >> >>> Matthias >> >>> >> >>> >> >>> >> >>> ___ >> >>> 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] Thunderbolt E failing
Hal Murray writes: > > p...@phk.freebsd.dk said: > > I later talked to a geologist who knows the Danish underground well, and he > > estimated I would have needed to drill to at least 25m depth to escape > > seasonal temperature-changes and cited a research paper from the 1950'ies > > where the did precisely that experiment. > > I found a paper showing skin depth at 1 year of 3-4 meters for soil, a bit > over 1 meter for ice and rock. Yes, as a general rule, the yearly temperature-swing attenuates a lot in about a meter or two, and that's why you generally bury a ground-heat loop buried a meter or so. But if you measure the temperature with one decimal place or better, you need to dig deeper, because now the difference between individual year's weather matter, and in my case here in Denmark: Underground water-transport and in particular where and when that water comes from starts to matter. Basically I would have had to drill to "the stable water table" and in my case that is approx 25 meters down, which is also the typical depth of atesian wells in Denmark. > Does a pipe in the ground stay dry? Or how do you keep in dry? In summer, > I'd expect it to be cool and if the humidity in the outside air is above X% > it > would condense in the pipe. Do you just cover the top to avoid air mixing? > Does in need a desiccant? ... It would need to be closed to the atmosphere, which you can either do properly or patch up the imperfection with desiccant. More tricky: Internal air-circulation. Either guarantee that the temperature increases all the way from the bottom to the top, which here in Denmark would mean heating the top-end during winter, or install baffles every 1-2 meters to resrict airflow. It would have been fun, but I can get the same temperature stability cheaper. -- 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] Thunderbolt E failing
I used special order PVC Pipe with end caps, used the drilling mud to encase it in the ground. The top cap had a U made up of PVC L's and was removable. Initial tests where without any filling. Once convinced it worked I filled the pipe with coin bags my local banker got me. Very strong canvas. Filled with gravel and sand.and a numbered string attached. Used it from 74 till 93 when I sold the home. Dug out 6 inches and filled it with dirt.Never detected any moisture.Used a Tracor M100 modified to 60 KHz for comparison it served me in Miami till 60 KHz was modified. Bert Kehren In a message dated 9/16/2020 1:16:24 AM Eastern Standard Time, hmur...@megapathdsl.net writes: p...@phk.freebsd.dk said:> I later talked to a geologist who knows the Danish underground well, and he> estimated I would have needed to drill to at least 25m depth to escape> seasonal temperature-changes and cited a research paper from the 1950'ies> where the did precisely that experiment. I found a paper showing skin depth at 1 year of 3-4 meters for soil, a bit over 1 meter for ice and rock. Does a pipe in the ground stay dry? Or how do you keep in dry? In summer, I'd expect it to be cool and if the humidity in the outside air is above X% it would condense in the pipe. Do you just cover the top to avoid air mixing? Does in need a desiccant? ... -- These are my opinions. I hate spam. ___time-nuts mailing list -- time-n...@lists.febo.comTo unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.comand 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] Thunderbolt E failing
p...@phk.freebsd.dk said: > I later talked to a geologist who knows the Danish underground well, and he > estimated I would have needed to drill to at least 25m depth to escape > seasonal temperature-changes and cited a research paper from the 1950'ies > where the did precisely that experiment. I found a paper showing skin depth at 1 year of 3-4 meters for soil, a bit over 1 meter for ice and rock. Does a pipe in the ground stay dry? Or how do you keep in dry? In summer, I'd expect it to be cool and if the humidity in the outside air is above X% it would condense in the pipe. Do you just cover the top to avoid air mixing? Does in need a desiccant? ... -- 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] Thunderbolt E failing
shouldbe q931 writes: > > Apart from the entire "get electronics wet" thing, water would have > > been near perfect. > > There are alternatives to water... > https://www.3m.co.uk/3M/en_GB/novec-uk/applications/immersion-cooling/ For very, very specific use-cases, yes. I have hard time seeing anybody dunk their OCXO or Rb... -- 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] Thunderbolt E failing
On Mon, Sep 14, 2020 at 10:36 AM Poul-Henning Kamp wrote: > > > Matthias Welwarsky writes: > > > > The point is that there is no need to compensate the part while it is > > > locked. > > > > It depends. For short time constants, yes, likely the control loop is able > > to > > follow the temperature-induced drift of the OCXO. But you might want the TC > > to > > be as long as possible. > > The word you are looking for here is not "Temperature Coefficient" > but "Thermal Impedance" (more on this below). > > > By following the temperature, you have an additional input that allows > > the controller to act more quickly to a changing environment. Effectively > > this > > will lead to higher stability of the output. > > Only if you first spend months and years measuring all the parameters > and time constants of the multiphysics model you use, well enough > to make useful predictions with it. > > > Maybe, but a linear approximation is probably better than nothing [...] > > No, it is usually worse. > > A major part of the trouble is the complex hysteresis-effects when > the temperture changes direction: The components which warm fast > also cools fast. > > For example: When the temp goes up you will likely find that your > DAC warms faster than the XTAL, but when the temp goes down it also > cools faster than the XTAL. > > That means the temperature difference between the DAC and XTAL depends > on the temperature rising or dropping, so you have to model the tempco > and temperature of them individually. > > > If you look at the attached screenshot - there's roughly 5500 seconds of > > data > > from my GPSDO. At about 2500 seconds the temperature compensation was > > engaged. > > This is nowhere near enough data to show anything. Collect a full > week with/without and we can talk. > > In the end, the proof is in your allan-variance, if it improves, you got > something, if it does not, you wasted your time. > > > The easiest and cheapest way for you to get better results, is to increase > the thermal impedance between the surroundings and your GPSDO. > > That will make the temperature change slower, which also means it > changes less and therefore your hysteresis effects also get smaller. > > Note that "thermal impedance" is not the same as "thermal insulation": > > Thermal insulation materials have high thermal resistance and low > thermal mass, and wrapping your GPSDO in that would just make it > run hot. > > Think of it is a thermal RC filter with a huge resistor and a small > capacitor. > > We want the a low to moderate resistor, so the GPSDO can still dump > its heat, with a huge capacitor to filter out the changes in > temperature. > > Apart from the entire "get electronics wet" thing, water would have > been near perfect. There are alternatives to water... https://www.3m.co.uk/3M/en_GB/novec-uk/applications/immersion-cooling/ Cheers Arne > > Table-top granite (about 2cm thick) is really great, but not very accessible. > > Metals almost conduct heat too well, but a box of 1-5cm thick iron > plates works great, but pay attention to the weight. > > For most of us, concrete is the way to go: > > Get three cinderblocks of the kind that looks like a 'H' with two > horizontal bars. > > Put the first cinderblock down on its side. > > Put the next cinderblock on top of it in normal orientation. > > Put your OCXO into the cavity. > > Hack notches in the edge of the cinderblock for the cables. > > Put the third cinderblock on top, also on its side. > > You have now increased the thermal impedance by almost two orders > of magnitude, and your PLL will be boored. > > If need be, you can make the central cavity more air-tight by > "sealing" between the cinderblocks with a layer of cloth or > tissue-paper. > > -- > 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] Thunderbolt E failing
ew via time-nuts writes: > In 1973 I moved for TI to Dallas and had a 20 foot hole drilled to place my > Sulzer One alternate.. Today I monitor my lab closely to better understand > what to do. The monitor is placed on the top of the HP5065A[...] When we built our new house I wanted to build some kind of "clock vault", but however I looked at it, it was either far too expensive or impossible to get planning permission for due to the ground water protection zoning. I later talked to a geologist who knows the Danish underground well, and he estimated I would have needed to drill to at least 25m depth to escape seasonal temperature-changes and cited a research paper from the 1950'ies where the did precisely that experiment. He also mentioned something I had not thought about my self: The ø=15cm end-capped dry steel-pipe I was dreaming of would have been subject to a LOT of upward boyancy force. -- 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] Thunderbolt E failing
Hi > On Sep 14, 2020, at 3:59 AM, Matthias Welwarsky > wrote: > > On Sonntag, 13. September 2020 15:05:36 CEST Bob kb8tq wrote: >> Hi >> >> The point is that there is no need to compensate the part while it is >> locked. > > It depends. For short time constants, yes, likely the control loop is able to > follow the temperature-induced drift of the OCXO At that point the part meets all relevant specifications. The customer is happy ( = it meets spec). Any further work on the part simply increases the cost of the device. Why would you do this if it already is fully spec compliant ? > . But you might want the TC to > be as long as possible. Naturally, the control loop becomes very slow to > react. By following the temperature, you have an additional input that allows > the controller to act more quickly to a changing environment. Effectively > this > will lead to higher stability of the output. If you spend a few years digging into this and trying various approaches, be sure to apply the same firmware to multiple devices. If it all is a “learning” process. How do you suggest training? The “worst case” will always be an excursion outside the normal variation the part sees….. If the data is collected in a formal fashion (via temperature test) and then programmed into the device, how stable is it long term? How is it impacted by air flow and unit orientation? ( hint: a lot ….). Not cheap or easy ….. Bob > >> Indeed, trying to compensate *and* learn at the same time generates even >> more issues to deal with. The temperature effect is not a simple linear / >> first order sort of thing …. > > Maybe, but a linear approximation is probably better than nothing as it still > reduces the amount of change that the control loop has to counteract. > > If you look at the attached screenshot - there's roughly 5500 seconds of data > from my GPSDO. At about 2500 seconds the temperature compensation was > engaged. > It's just a linear correction factor for the DAC output. The factor was > computed using a linear regression fit to find the correlation between the > temperature and the OCXO drift. In the DAC chart the blue trace is the > actual, > corrected DAC output, the orange trace is the uncorrected DAC computed from > the TIC input. The green trace is the OCXO drift. Without the temperature > compensation, the TIC takes a dive down to almost -15ns. While the > temperature > continues its decline at an approximately constant rate, after the > compensation was engaged the TIC excursions are smaller and therefore the > stability of the output higher. > > Now, of course the picture gets somewhat muddy if you keep computing the > compensation factor while the compensation is active, but what you still get > is a _residual_ factor, which you can maybe use to refine the compensation > subsequently. The correlation factor (r_xy) will tell if there's still > something to be done. > >> >> Bob >> >>> On Sep 13, 2020, at 1:41 AM, Matthias Welwarsky >>> wrote:> >>> On Samstag, 12. September 2020 23:53:39 CEST Bob kb8tq wrote: Hi As far as anybody knows (which *is* a big qualifier indeed ….), the TBolt family only does it’s “temperature compensation” stuff when it’s in holdover. While it’s locked, there *appears* to be no compensation being done. If it’s doing anything while locked, it’s learning what the TC is, so it can use that information while in holdover. >>> >>> That is interesting, why wouldn't they use the information if it's >>> available? Watching the temperature gives you a prediction of what is >>> going to happen, while watching the phase only shows what has already >>> happened. And knowing what's about to happen is always very favorable in >>> control theory.> Bob > On Sep 12, 2020, at 3:52 PM, Matthias Welwarsky > wrote: > > Kevin, > > how long has it been in storage? I expect the GPSDO doing quite clever > things to compensate for temperature effects. There may be some > parameters stored on the device and the characteristics of the OCXO may > have changed after being turned off for an extended period. > > Regards, > Matthias > > On Samstag, 12. September 2020 18:13:35 CEST Kevin Schuchmann wrote: >> Matthias, >> >> You are correct, having spent hours looking at all the stable areas >> >> and cooling and heating the gpsdo I find that when it reports that it >> is >> 116.25 F then it is stable. >> So now I guess I need to figure out why it is so picky. I will measure >> the current draw from a cold start and see if I see the oven warming up >> and then stabilizing and then heat and cool it and see how it reacts, >> and also look at the electronics and see if an area is overly sensitive >> to temperature. >> >> Thanks >> Kevin >> >> On 9/11/2020 2:26 AM, Matthias Welwarsky
Re: [time-nuts] Thunderbolt E failing
Matthias Welwarsky writes: > > The point is that there is no need to compensate the part while it is > > locked. > > It depends. For short time constants, yes, likely the control loop is able to > follow the temperature-induced drift of the OCXO. But you might want the TC > to > be as long as possible. The word you are looking for here is not "Temperature Coefficient" but "Thermal Impedance" (more on this below). > By following the temperature, you have an additional input that allows > the controller to act more quickly to a changing environment. Effectively > this > will lead to higher stability of the output. Only if you first spend months and years measuring all the parameters and time constants of the multiphysics model you use, well enough to make useful predictions with it. > Maybe, but a linear approximation is probably better than nothing [...] No, it is usually worse. A major part of the trouble is the complex hysteresis-effects when the temperture changes direction: The components which warm fast also cools fast. For example: When the temp goes up you will likely find that your DAC warms faster than the XTAL, but when the temp goes down it also cools faster than the XTAL. That means the temperature difference between the DAC and XTAL depends on the temperature rising or dropping, so you have to model the tempco and temperature of them individually. > If you look at the attached screenshot - there's roughly 5500 seconds of data > from my GPSDO. At about 2500 seconds the temperature compensation was > engaged. This is nowhere near enough data to show anything. Collect a full week with/without and we can talk. In the end, the proof is in your allan-variance, if it improves, you got something, if it does not, you wasted your time. The easiest and cheapest way for you to get better results, is to increase the thermal impedance between the surroundings and your GPSDO. That will make the temperature change slower, which also means it changes less and therefore your hysteresis effects also get smaller. Note that "thermal impedance" is not the same as "thermal insulation": Thermal insulation materials have high thermal resistance and low thermal mass, and wrapping your GPSDO in that would just make it run hot. Think of it is a thermal RC filter with a huge resistor and a small capacitor. We want the a low to moderate resistor, so the GPSDO can still dump its heat, with a huge capacitor to filter out the changes in temperature. Apart from the entire "get electronics wet" thing, water would have been near perfect. Table-top granite (about 2cm thick) is really great, but not very accessible. Metals almost conduct heat too well, but a box of 1-5cm thick iron plates works great, but pay attention to the weight. For most of us, concrete is the way to go: Get three cinderblocks of the kind that looks like a 'H' with two horizontal bars. Put the first cinderblock down on its side. Put the next cinderblock on top of it in normal orientation. Put your OCXO into the cavity. Hack notches in the edge of the cinderblock for the cables. Put the third cinderblock on top, also on its side. You have now increased the thermal impedance by almost two orders of magnitude, and your PLL will be boored. If need be, you can make the central cavity more air-tight by "sealing" between the cinderblocks with a layer of cloth or tissue-paper. -- 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] Thunderbolt E failing
Hi Ok so you have a step change in temperature of say 2C over 5 seconds. What (might) happen: (Yes this is all a bit contrived, but it *is* the sort of thing that’s going on in the TBolt). The units shown are “Bob Units” :). They have no particular relation to LSB’s or to PPT’s. At 18 seconds, the DAC chip warms up and the frequency goes up by 3.7 At 32 seconds the DAC reference warms up and the frequency goes down by 1.2 At 45 seconds the temperature sensor on the TBolt begins to register the change…... At 1 minute your voltage regulator on your 5V supply warms up and the frequency goes up by 0.2 At 2 minutes your voltage regulator on your 12V supply warms up and the frequency goes down by 0.6 At 4 minutes the outer part of the oven “sees” the temperature and the frequency goes up by 0.2 At 6 minutes the crystal “sees” the temperature and it goes up by 1.4 for the next 9 seconds and then decays to -0.2 and on and on and on …. Since all of that is additive, sorting this or that out … yikes. It also turns out to be rate dependent ( = a slower change significantly impacts some of the numbers ). Blow air in from a different direction and the sequence of what sees what when may be entirely different. So just *what* are you compensating? Bob > On Sep 13, 2020, at 2:29 PM, Hal Murray wrote: > > > time-n...@welwarsky.de said: >> That is interesting, why wouldn't they use the information if it's available? >> Watching the temperature gives you a prediction of what is going to happen, >> while watching the phase only shows what has already happened. And knowing >> what's about to happen is always very favorable in control theory. > > You can probably measure the temperature more accurately by measuring the > frequency. > > > -- > 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.
Re: [time-nuts] Thunderbolt E failing
Bob kb8tq writes: > The point is that there is no need to compensate the part while it is locked. > It meets all the specs required of it by virtue of the lock to GPS. The big > issue > on these devices ( = cell tower GPSDO’s) is holdover. That’s where all the > magic comes in. > > Indeed, trying to compensate *and* learn at the same time generates even > more issues to deal with. The temperature effect is not a simple linear / > first > order sort of thing …. Data point: 20 years ago, I needed to buy a batch of a dozen OCXO's for hand-built NTP servers for the new danish ATC network. This is where the Soekris 4501 trick comes from, and I wanted a frequency I could feed directly to the Soekris if at all possible. I ended up "buying into" an existing production run of IsoTemp OCXO-0131's at 32.768 MHz spec'ed for "some telco application". I attach a 16 year long plot of the frequency error for one of the servers on my side of the firewall-of-doom. (There were a network misconfiguration, so the data from middle of 2011 to end of 2015 is not valid - long story, mostly about fibers and backhoes) It took this one five years to "settle in", but for the last decade it has consistently drifted 2.2e-9/year = 7e-16/second. The software PLL in these NTP servers did model drift and we tested that, unplugging the GPS antenna on one server. After 18 weeks in hold-over it had still not drifted out of spec. In the 19th week, they added two 3.5" disks to a server mounted in the same rack, literally opening the rack-door, checking the dymo to make sure they had the right server, pulling out the spacers, stuck in the disks, clsoed the rack-door and left the room. The plot for that server clearly shows a change in OCXO-behaviour and 121 hours later, the NTP finally wandered out of spec. Other tests rules out thermal causes, so our conclusion is that either the vibration from the intervention or from the rotation of the two new disks did it. My personal conclusion is that high-order PLL's are fun, but they require patience on a timescale of years and you need not bother unless you have a *very* benign environment. Poul-Henning -- 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] Thunderbolt E failing
Hi Not done that way in this case. Keep in mind that the “stock” configuration only runs a loop time constant in the 10’s of seconds. On the TBolt, the main source of temperature error is the DAC. Tossing a bit more “stuff” at that part of the design would have been higher on the list than playing with compensation. It met the spec so why spend the money ….. Bob > On Sep 13, 2020, at 10:28 AM, Adrian Godwin wrote: > > But doesn't the compensation help generate a feed-forward term, a way to > make the integrator better managed ? > > On Sun, Sep 13, 2020 at 2:31 PM Bob kb8tq wrote: > >> Hi >> >> The point is that there is no need to compensate the part while it is >> locked. >> It meets all the specs required of it by virtue of the lock to GPS. The >> big issue >> on these devices ( = cell tower GPSDO’s) is holdover. That’s where all the >> magic comes in. >> >> Indeed, trying to compensate *and* learn at the same time generates even >> more issues to deal with. The temperature effect is not a simple linear / >> first >> order sort of thing …. >> >> Bob >> >>> On Sep 13, 2020, at 1:41 AM, Matthias Welwarsky >> wrote: >>> >>> On Samstag, 12. September 2020 23:53:39 CEST Bob kb8tq wrote: Hi As far as anybody knows (which *is* a big qualifier indeed ….), the >> TBolt family only does it’s “temperature compensation” stuff when it’s in holdover. While it’s locked, there *appears* to be no compensation being done. If it’s doing anything while locked, it’s learning what the TC >> is, so it can use that information while in holdover. >>> >>> That is interesting, why wouldn't they use the information if it's >> available? >>> Watching the temperature gives you a prediction of what is going to >> happen, >>> while watching the phase only shows what has already happened. And >> knowing >>> what's about to happen is always very favorable in control theory. >>> Bob > On Sep 12, 2020, at 3:52 PM, Matthias Welwarsky < >> time-n...@welwarsky.de> > wrote: > > Kevin, > > how long has it been in storage? I expect the GPSDO doing quite clever > things to compensate for temperature effects. There may be some > parameters stored on the device and the characteristics of the OCXO may > have changed after being turned off for an extended period. > > Regards, > Matthias > > On Samstag, 12. September 2020 18:13:35 CEST Kevin Schuchmann wrote: >> Matthias, >> >> You are correct, having spent hours looking at all the stable areas >> >> and cooling and heating the gpsdo I find that when it reports that it >> is >> 116.25 F then it is stable. >> So now I guess I need to figure out why it is so picky. I will measure >> the current draw from a cold start and see if I see the oven warming >> up >> and then stabilizing and then heat and cool it and see how it reacts, >> and also look at the electronics and see if an area is overly >> sensitive >> to temperature. >> >> Thanks >> Kevin >> >> On 9/11/2020 2:26 AM, Matthias Welwarsky wrote: >>> On Freitag, 11. September 2020 01:08:09 CEST Kevin Schuchmann wrote: Guess my image didn't make it, I will add it as an attachment this time. >>> >>> The temperature curve seems to show some correlation to what is >>> happening >>> with the DAC. Seems that the DAC and OSC jumps are mostly during >> periods >>> of some thermal perturbation. >>> >>> Regards, >>> Matthias >>> >>> >>> >>> ___ >>> 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
Re: [time-nuts] Thunderbolt E failing
time-n...@welwarsky.de said: > That is interesting, why wouldn't they use the information if it's available? > Watching the temperature gives you a prediction of what is going to happen, > while watching the phase only shows what has already happened. And knowing > what's about to happen is always very favorable in control theory. You can probably measure the temperature more accurately by measuring the frequency. -- 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] Thunderbolt E failing
But doesn't the compensation help generate a feed-forward term, a way to make the integrator better managed ? On Sun, Sep 13, 2020 at 2:31 PM Bob kb8tq wrote: > Hi > > The point is that there is no need to compensate the part while it is > locked. > It meets all the specs required of it by virtue of the lock to GPS. The > big issue > on these devices ( = cell tower GPSDO’s) is holdover. That’s where all the > magic comes in. > > Indeed, trying to compensate *and* learn at the same time generates even > more issues to deal with. The temperature effect is not a simple linear / > first > order sort of thing …. > > Bob > > > On Sep 13, 2020, at 1:41 AM, Matthias Welwarsky > wrote: > > > > On Samstag, 12. September 2020 23:53:39 CEST Bob kb8tq wrote: > >> Hi > >> > >> As far as anybody knows (which *is* a big qualifier indeed ….), the > TBolt > >> family only does it’s “temperature compensation” stuff when it’s in > >> holdover. While it’s locked, there *appears* to be no compensation being > >> done. If it’s doing anything while locked, it’s learning what the TC > is, so > >> it can use that information while in holdover. > > > > That is interesting, why wouldn't they use the information if it's > available? > > Watching the temperature gives you a prediction of what is going to > happen, > > while watching the phase only shows what has already happened. And > knowing > > what's about to happen is always very favorable in control theory. > > > >> > >> Bob > >> > >>> On Sep 12, 2020, at 3:52 PM, Matthias Welwarsky < > time-n...@welwarsky.de> > >>> wrote: > >>> > >>> Kevin, > >>> > >>> how long has it been in storage? I expect the GPSDO doing quite clever > >>> things to compensate for temperature effects. There may be some > >>> parameters stored on the device and the characteristics of the OCXO may > >>> have changed after being turned off for an extended period. > >>> > >>> Regards, > >>> Matthias > >>> > >>> On Samstag, 12. September 2020 18:13:35 CEST Kevin Schuchmann wrote: > Matthias, > > You are correct, having spent hours looking at all the stable areas > > and cooling and heating the gpsdo I find that when it reports that it > is > 116.25 F then it is stable. > So now I guess I need to figure out why it is so picky. I will measure > the current draw from a cold start and see if I see the oven warming > up > and then stabilizing and then heat and cool it and see how it reacts, > and also look at the electronics and see if an area is overly > sensitive > to temperature. > > Thanks > Kevin > > On 9/11/2020 2:26 AM, Matthias Welwarsky wrote: > > On Freitag, 11. September 2020 01:08:09 CEST Kevin Schuchmann wrote: > >> Guess my image didn't make it, I will add it as an attachment this > >> time. > > > > The temperature curve seems to show some correlation to what is > > happening > > with the DAC. Seems that the DAC and OSC jumps are mostly during > periods > > of some thermal perturbation. > > > > Regards, > > Matthias > > > > > > > > ___ > > 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 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] Thunderbolt E failing
Hi The point is that there is no need to compensate the part while it is locked. It meets all the specs required of it by virtue of the lock to GPS. The big issue on these devices ( = cell tower GPSDO’s) is holdover. That’s where all the magic comes in. Indeed, trying to compensate *and* learn at the same time generates even more issues to deal with. The temperature effect is not a simple linear / first order sort of thing …. Bob > On Sep 13, 2020, at 1:41 AM, Matthias Welwarsky > wrote: > > On Samstag, 12. September 2020 23:53:39 CEST Bob kb8tq wrote: >> Hi >> >> As far as anybody knows (which *is* a big qualifier indeed ….), the TBolt >> family only does it’s “temperature compensation” stuff when it’s in >> holdover. While it’s locked, there *appears* to be no compensation being >> done. If it’s doing anything while locked, it’s learning what the TC is, so >> it can use that information while in holdover. > > That is interesting, why wouldn't they use the information if it's available? > Watching the temperature gives you a prediction of what is going to happen, > while watching the phase only shows what has already happened. And knowing > what's about to happen is always very favorable in control theory. > >> >> Bob >> >>> On Sep 12, 2020, at 3:52 PM, Matthias Welwarsky >>> wrote: >>> >>> Kevin, >>> >>> how long has it been in storage? I expect the GPSDO doing quite clever >>> things to compensate for temperature effects. There may be some >>> parameters stored on the device and the characteristics of the OCXO may >>> have changed after being turned off for an extended period. >>> >>> Regards, >>> Matthias >>> >>> On Samstag, 12. September 2020 18:13:35 CEST Kevin Schuchmann wrote: Matthias, You are correct, having spent hours looking at all the stable areas and cooling and heating the gpsdo I find that when it reports that it is 116.25 F then it is stable. So now I guess I need to figure out why it is so picky. I will measure the current draw from a cold start and see if I see the oven warming up and then stabilizing and then heat and cool it and see how it reacts, and also look at the electronics and see if an area is overly sensitive to temperature. Thanks Kevin On 9/11/2020 2:26 AM, Matthias Welwarsky wrote: > On Freitag, 11. September 2020 01:08:09 CEST Kevin Schuchmann wrote: >> Guess my image didn't make it, I will add it as an attachment this >> time. > > The temperature curve seems to show some correlation to what is > happening > with the DAC. Seems that the DAC and OSC jumps are mostly during periods > of some thermal perturbation. > > Regards, > Matthias > > > > ___ > 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.
Re: [time-nuts] Thunderbolt E failing
On Samstag, 12. September 2020 23:53:39 CEST Bob kb8tq wrote: > Hi > > As far as anybody knows (which *is* a big qualifier indeed ….), the TBolt > family only does it’s “temperature compensation” stuff when it’s in > holdover. While it’s locked, there *appears* to be no compensation being > done. If it’s doing anything while locked, it’s learning what the TC is, so > it can use that information while in holdover. That is interesting, why wouldn't they use the information if it's available? Watching the temperature gives you a prediction of what is going to happen, while watching the phase only shows what has already happened. And knowing what's about to happen is always very favorable in control theory. > > Bob > > > On Sep 12, 2020, at 3:52 PM, Matthias Welwarsky > > wrote: > > > > Kevin, > > > > how long has it been in storage? I expect the GPSDO doing quite clever > > things to compensate for temperature effects. There may be some > > parameters stored on the device and the characteristics of the OCXO may > > have changed after being turned off for an extended period. > > > > Regards, > > Matthias > > > > On Samstag, 12. September 2020 18:13:35 CEST Kevin Schuchmann wrote: > >> Matthias, > >> > >>You are correct, having spent hours looking at all the stable areas > >> > >> and cooling and heating the gpsdo I find that when it reports that it is > >> 116.25 F then it is stable. > >> So now I guess I need to figure out why it is so picky. I will measure > >> the current draw from a cold start and see if I see the oven warming up > >> and then stabilizing and then heat and cool it and see how it reacts, > >> and also look at the electronics and see if an area is overly sensitive > >> to temperature. > >> > >> Thanks > >> Kevin > >> > >> On 9/11/2020 2:26 AM, Matthias Welwarsky wrote: > >>> On Freitag, 11. September 2020 01:08:09 CEST Kevin Schuchmann wrote: > Guess my image didn't make it, I will add it as an attachment this > time. > >>> > >>> The temperature curve seems to show some correlation to what is > >>> happening > >>> with the DAC. Seems that the DAC and OSC jumps are mostly during periods > >>> of some thermal perturbation. > >>> > >>> Regards, > >>> Matthias > >>> > >>> > >>> > >>> ___ > >>> 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] Thunderbolt E failing
Hi The unit you most commonly see is a version done for E911 cell tower upgrades. It was an intermediate step to add that functionality before it could be done internal to the cell base station. Once the “real” solution came along, the E911 boxes became scrap. They went off to China to be salvaged. The one in the listing is simply the board you normally see mated up with a power supply. Trimble shipped them out mainly as evaluation devices. The bulk of what was produced went into the E911 application. There is a bunch of information on all this back in the archives 10 to 15 years ago. Searching those archives is a bit of a challenge with all the changes in the list over the years. Functionally, there is no difference between the one you are looking at and the more common one. Both came in a variety of firmware versions. Both have a range of OCXO’s in them (99% all from the same source, but changing designs over the years …). Without digging into the exact board, there is no easy way to see what’s what. The good news is that they all pretty much work fine. Bob > On Sep 12, 2020, at 5:43 PM, Adrian Godwin wrote: > > Thanks! > > The one I've seen pictured most often comes in a (I think) slightly lower > gold-coloured (alocromed) case. > e.g. http://www.sydneystormcity.com/TrimbleThunderboltGPS.jpg > Is that any different ? > > I did order the one from my link so will report on any markings. The vendor > mentioned part 48050-61 but as you say, that seems to be common to all of > them. > > > On Sat, Sep 12, 2020 at 10:14 PM Bob kb8tq wrote: > >> Hi >> >> The unit your link points to *is* the “classic” TBolt that showed up in >> volume a bit >> over a decade ago. That one is packaged with a (noisy) switching power >> supply. >> >> There is no easy way to tell what era it is from. Indeed if it is from the >> 1990’s the >> OCXO will not be quite as good as what’s in one from > 2002. Since the >> unit normally >> operates locked, that’s not a real big deal. >> >> Since Trimble used “Thunderbolt” for a whole line of parts *and* was not >> very good >> at labeling devices, there is no easy way to refer to this or that >> specific device. That >> makes coming up with a list of units a bit hard. For example - what’s the >> model number >> of the part in that eBay listing ? ( No I don’t know either …. :) ). >> >> Bob >> >>> On Sep 12, 2020, at 12:28 PM, Adrian Godwin wrote: >>> >>> I've been looking for a thunderbolt for a while, mostly because they're >>> such a benchmark within this group. I missed the period when they were >> more >>> commonly available and have mostly found ones that were a lot more >>> expensive, or had a large delivery cost due to being in Australia. >>> >>> Some cheaper examples turned up on UK ebay. These aren't the classic >>> time-nuts ones but presumably look fairly similar to Lady Heather. >>> >>> https://www.ebay.co.uk/itm/154078750287 >>> >>> I haven't been able to find a comparison of the various thunderbolt >> models. >>> Is there a description somewhere ? I've found a few hints about this one >> - >>> I think it's a single 48V supply and possibly a lower-quality OCXO. >>> >>> On Sat, Sep 12, 2020 at 5:14 PM Kevin Schuchmann >> wrote: >>> Matthias, You are correct, having spent hours looking at all the stable areas and cooling and heating the gpsdo I find that when it reports that it is 116.25 F then it is stable. So now I guess I need to figure out why it is so picky. I will measure the current draw from a cold start and see if I see the oven warming up and then stabilizing and then heat and cool it and see how it reacts, and also look at the electronics and see if an area is overly sensitive to temperature. Thanks Kevin On 9/11/2020 2:26 AM, Matthias Welwarsky wrote: > On Freitag, 11. September 2020 01:08:09 CEST Kevin Schuchmann wrote: >> Guess my image didn't make it, I will add it as an attachment this >> time. > The temperature curve seems to show some correlation to what is happening with > the DAC. Seems that the DAC and OSC jumps are mostly during periods of some > thermal perturbation. > > Regards, > Matthias > > > > ___ > 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 >>
Re: [time-nuts] Thunderbolt E failing
Thanks! The one I've seen pictured most often comes in a (I think) slightly lower gold-coloured (alocromed) case. e.g. http://www.sydneystormcity.com/TrimbleThunderboltGPS.jpg Is that any different ? I did order the one from my link so will report on any markings. The vendor mentioned part 48050-61 but as you say, that seems to be common to all of them. On Sat, Sep 12, 2020 at 10:14 PM Bob kb8tq wrote: > Hi > > The unit your link points to *is* the “classic” TBolt that showed up in > volume a bit > over a decade ago. That one is packaged with a (noisy) switching power > supply. > > There is no easy way to tell what era it is from. Indeed if it is from the > 1990’s the > OCXO will not be quite as good as what’s in one from > 2002. Since the > unit normally > operates locked, that’s not a real big deal. > > Since Trimble used “Thunderbolt” for a whole line of parts *and* was not > very good > at labeling devices, there is no easy way to refer to this or that > specific device. That > makes coming up with a list of units a bit hard. For example - what’s the > model number > of the part in that eBay listing ? ( No I don’t know either …. :) ). > > Bob > > > On Sep 12, 2020, at 12:28 PM, Adrian Godwin wrote: > > > > I've been looking for a thunderbolt for a while, mostly because they're > > such a benchmark within this group. I missed the period when they were > more > > commonly available and have mostly found ones that were a lot more > > expensive, or had a large delivery cost due to being in Australia. > > > > Some cheaper examples turned up on UK ebay. These aren't the classic > > time-nuts ones but presumably look fairly similar to Lady Heather. > > > > https://www.ebay.co.uk/itm/154078750287 > > > > I haven't been able to find a comparison of the various thunderbolt > models. > > Is there a description somewhere ? I've found a few hints about this one > - > > I think it's a single 48V supply and possibly a lower-quality OCXO. > > > > On Sat, Sep 12, 2020 at 5:14 PM Kevin Schuchmann > wrote: > > > >> Matthias, > >>You are correct, having spent hours looking at all the stable areas > >> and cooling and heating the gpsdo I find that when it reports that it is > >> 116.25 F then it is stable. > >> So now I guess I need to figure out why it is so picky. I will measure > >> the current draw from a cold start and see if I see the oven warming up > >> and then stabilizing and then heat and cool it and see how it reacts, > >> and also look at the electronics and see if an area is overly sensitive > >> to temperature. > >> > >> Thanks > >> Kevin > >> > >> > >> On 9/11/2020 2:26 AM, Matthias Welwarsky wrote: > >>> On Freitag, 11. September 2020 01:08:09 CEST Kevin Schuchmann wrote: > Guess my image didn't make it, I will add it as an attachment this > time. > >>> The temperature curve seems to show some correlation to what is > >> happening with > >>> the DAC. Seems that the DAC and OSC jumps are mostly during periods of > >> some > >>> thermal perturbation. > >>> > >>> Regards, > >>> Matthias > >>> > >>> > >>> > >>> ___ > >>> 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] Thunderbolt E failing
Hi As far as anybody knows (which *is* a big qualifier indeed ….), the TBolt family only does it’s “temperature compensation” stuff when it’s in holdover. While it’s locked, there *appears* to be no compensation being done. If it’s doing anything while locked, it’s learning what the TC is, so it can use that information while in holdover. Bob > On Sep 12, 2020, at 3:52 PM, Matthias Welwarsky > wrote: > > Kevin, > > how long has it been in storage? I expect the GPSDO doing quite clever things > to compensate for temperature effects. There may be some parameters stored on > the device and the characteristics of the OCXO may have changed after being > turned off for an extended period. > > Regards, > Matthias > > On Samstag, 12. September 2020 18:13:35 CEST Kevin Schuchmann wrote: >> Matthias, >>You are correct, having spent hours looking at all the stable areas >> and cooling and heating the gpsdo I find that when it reports that it is >> 116.25 F then it is stable. >> So now I guess I need to figure out why it is so picky. I will measure >> the current draw from a cold start and see if I see the oven warming up >> and then stabilizing and then heat and cool it and see how it reacts, >> and also look at the electronics and see if an area is overly sensitive >> to temperature. >> >> Thanks >> Kevin >> >> On 9/11/2020 2:26 AM, Matthias Welwarsky wrote: >>> On Freitag, 11. September 2020 01:08:09 CEST Kevin Schuchmann wrote: Guess my image didn't make it, I will add it as an attachment this time. >>> >>> The temperature curve seems to show some correlation to what is happening >>> with the DAC. Seems that the DAC and OSC jumps are mostly during periods >>> of some thermal perturbation. >>> >>> Regards, >>> Matthias >>> >>> >>> >>> ___ >>> 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] Thunderbolt E failing
Kevin, Can you post your Lady Heather config file and command line options that created that image ? George On 9/10/2020 19:08, Kevin Schuchmann wrote: Guess my image didn't make it, I will add it as an attachment this time. Swapped power supplies no difference. Antenna is on a splitter shared with a non E thunderbolt and it is working fine along with a NTP100 and Tymserve 2100 with no complaints from them. I will try disconnecting the antenna and see what happens. Thanks for the suggestions. Kevin On 9/10/2020 2:41 PM, Bob kb8tq wrote: Hi A couple things to check: 1) Is your power supply doing odd things? It’s the first thing I’d suspect in this case. 2) Does the OCXO “behave” if you turn off the GPS ( = disconnect the antenna ) and watch it with a counter? 3) While the antenna is disconnected from the TBolt, hook it to something else and see how it’s doing? 4) What does. LH show for sats and all the other stuff as this is going on ? Bob On Sep 10, 2020, at 2:40 PM, Kevin Schuchmann wrote: Newbie here looking for comments from people with more experience with thunderbolt E's to comment on what I am seeing. Unit is jumping and ramping the DAC one direction then goes stable for a bit only to start jumping and ramping the other way. Oscillator heading south or more likely the electronics package? Was running OK, shutdown and put away for months and then restarted and has been running like this for months and not settling down. Thanks Kevin ___ 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] Thunderbolt E failing
Kevin, how long has it been in storage? I expect the GPSDO doing quite clever things to compensate for temperature effects. There may be some parameters stored on the device and the characteristics of the OCXO may have changed after being turned off for an extended period. Regards, Matthias On Samstag, 12. September 2020 18:13:35 CEST Kevin Schuchmann wrote: > Matthias, > You are correct, having spent hours looking at all the stable areas > and cooling and heating the gpsdo I find that when it reports that it is > 116.25 F then it is stable. > So now I guess I need to figure out why it is so picky. I will measure > the current draw from a cold start and see if I see the oven warming up > and then stabilizing and then heat and cool it and see how it reacts, > and also look at the electronics and see if an area is overly sensitive > to temperature. > > Thanks > Kevin > > On 9/11/2020 2:26 AM, Matthias Welwarsky wrote: > > On Freitag, 11. September 2020 01:08:09 CEST Kevin Schuchmann wrote: > >> Guess my image didn't make it, I will add it as an attachment this time. > > > > The temperature curve seems to show some correlation to what is happening > > with the DAC. Seems that the DAC and OSC jumps are mostly during periods > > of some thermal perturbation. > > > > Regards, > > Matthias > > > > > > > > ___ > > 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] Thunderbolt E failing
Hi The unit your link points to *is* the “classic” TBolt that showed up in volume a bit over a decade ago. That one is packaged with a (noisy) switching power supply. There is no easy way to tell what era it is from. Indeed if it is from the 1990’s the OCXO will not be quite as good as what’s in one from > 2002. Since the unit normally operates locked, that’s not a real big deal. Since Trimble used “Thunderbolt” for a whole line of parts *and* was not very good at labeling devices, there is no easy way to refer to this or that specific device. That makes coming up with a list of units a bit hard. For example - what’s the model number of the part in that eBay listing ? ( No I don’t know either …. :) ). Bob > On Sep 12, 2020, at 12:28 PM, Adrian Godwin wrote: > > I've been looking for a thunderbolt for a while, mostly because they're > such a benchmark within this group. I missed the period when they were more > commonly available and have mostly found ones that were a lot more > expensive, or had a large delivery cost due to being in Australia. > > Some cheaper examples turned up on UK ebay. These aren't the classic > time-nuts ones but presumably look fairly similar to Lady Heather. > > https://www.ebay.co.uk/itm/154078750287 > > I haven't been able to find a comparison of the various thunderbolt models. > Is there a description somewhere ? I've found a few hints about this one - > I think it's a single 48V supply and possibly a lower-quality OCXO. > > On Sat, Sep 12, 2020 at 5:14 PM Kevin Schuchmann wrote: > >> Matthias, >>You are correct, having spent hours looking at all the stable areas >> and cooling and heating the gpsdo I find that when it reports that it is >> 116.25 F then it is stable. >> So now I guess I need to figure out why it is so picky. I will measure >> the current draw from a cold start and see if I see the oven warming up >> and then stabilizing and then heat and cool it and see how it reacts, >> and also look at the electronics and see if an area is overly sensitive >> to temperature. >> >> Thanks >> Kevin >> >> >> On 9/11/2020 2:26 AM, Matthias Welwarsky wrote: >>> On Freitag, 11. September 2020 01:08:09 CEST Kevin Schuchmann wrote: Guess my image didn't make it, I will add it as an attachment this time. >>> The temperature curve seems to show some correlation to what is >> happening with >>> the DAC. Seems that the DAC and OSC jumps are mostly during periods of >> some >>> thermal perturbation. >>> >>> Regards, >>> Matthias >>> >>> >>> >>> ___ >>> 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] Thunderbolt E failing
I've been looking for a thunderbolt for a while, mostly because they're such a benchmark within this group. I missed the period when they were more commonly available and have mostly found ones that were a lot more expensive, or had a large delivery cost due to being in Australia. Some cheaper examples turned up on UK ebay. These aren't the classic time-nuts ones but presumably look fairly similar to Lady Heather. https://www.ebay.co.uk/itm/154078750287 I haven't been able to find a comparison of the various thunderbolt models. Is there a description somewhere ? I've found a few hints about this one - I think it's a single 48V supply and possibly a lower-quality OCXO. On Sat, Sep 12, 2020 at 5:14 PM Kevin Schuchmann wrote: > Matthias, > You are correct, having spent hours looking at all the stable areas > and cooling and heating the gpsdo I find that when it reports that it is > 116.25 F then it is stable. > So now I guess I need to figure out why it is so picky. I will measure > the current draw from a cold start and see if I see the oven warming up > and then stabilizing and then heat and cool it and see how it reacts, > and also look at the electronics and see if an area is overly sensitive > to temperature. > > Thanks > Kevin > > > On 9/11/2020 2:26 AM, Matthias Welwarsky wrote: > > On Freitag, 11. September 2020 01:08:09 CEST Kevin Schuchmann wrote: > >> Guess my image didn't make it, I will add it as an attachment this time. > > The temperature curve seems to show some correlation to what is > happening with > > the DAC. Seems that the DAC and OSC jumps are mostly during periods of > some > > thermal perturbation. > > > > Regards, > > Matthias > > > > > > > > ___ > > 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] Thunderbolt E failing
Matthias, You are correct, having spent hours looking at all the stable areas and cooling and heating the gpsdo I find that when it reports that it is 116.25 F then it is stable. So now I guess I need to figure out why it is so picky. I will measure the current draw from a cold start and see if I see the oven warming up and then stabilizing and then heat and cool it and see how it reacts, and also look at the electronics and see if an area is overly sensitive to temperature. Thanks Kevin On 9/11/2020 2:26 AM, Matthias Welwarsky wrote: On Freitag, 11. September 2020 01:08:09 CEST Kevin Schuchmann wrote: Guess my image didn't make it, I will add it as an attachment this time. The temperature curve seems to show some correlation to what is happening with the DAC. Seems that the DAC and OSC jumps are mostly during periods of some thermal perturbation. Regards, Matthias ___ 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] Thunderbolt E failing
On Freitag, 11. September 2020 01:08:09 CEST Kevin Schuchmann wrote: > Guess my image didn't make it, I will add it as an attachment this time. The temperature curve seems to show some correlation to what is happening with the DAC. Seems that the DAC and OSC jumps are mostly during periods of some thermal perturbation. Regards, Matthias ___ 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] Thunderbolt E failing
Hi A couple things to check: 1) Is your power supply doing odd things? It’s the first thing I’d suspect in this case. 2) Does the OCXO “behave” if you turn off the GPS ( = disconnect the antenna ) and watch it with a counter? 3) While the antenna is disconnected from the TBolt, hook it to something else and see how it’s doing? 4) What does. LH show for sats and all the other stuff as this is going on ? Bob > On Sep 10, 2020, at 2:40 PM, Kevin Schuchmann wrote: > > Newbie here looking for comments from people with more experience with > thunderbolt E's to comment on what I am seeing. > Unit is jumping and ramping the DAC one direction then goes stable for a bit > only to start jumping and ramping the other way. > Oscillator heading south or more likely the electronics package? > > Was running OK, shutdown and put away for months and then restarted and has > been running like this for months and not settling down. > > Thanks > Kevin > > > > ___ > 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] Thunderbolt E failing
Newbie here looking for comments from people with more experience with thunderbolt E's to comment on what I am seeing. Unit is jumping and ramping the DAC one direction then goes stable for a bit only to start jumping and ramping the other way. Oscillator heading south or more likely the electronics package? Was running OK, shutdown and put away for months and then restarted and has been running like this for months and not settling down. Thanks Kevin ___ 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] Thunderbolt E
Hi John, That repair cost is enough to steer me away from buying one. I have a mediocre view of the sky with my current antenna setup. I'll continue on and research some additional possibilities for a GPSDO unit. Thanks for sharing your experience with the Thunderbolt E unit. Chris On 07/12/19 04:00:39, Jon “KF5TFJ” Noxon wrote: Chris, i have one which I bought new several years ago. It had a failure under warranty where in the serial chip stopped doing its thing. The unit continued to lock to SVs and delivered 10MHz and the PPS. Took almost two months to be returned, where it worked fine until very recently. Same issue with the serial chip. Trimble quoted a price of $650 for repairs. Ouch. As they say "Other than that Mrs Lincoln, how did you enjoy the play...”, it played fine as long as you could talk to it. Antenna location is very important as is true for all timing GPS units. The fit is supplied with a good length of 75 Ohn coax, power supply, antenna, and some coas adapters. So the question is how much do you intend to spend? Lady Heather works great when the serial chip was still good. Jon KF5TFJ Re: Date: Thu, 11 Jul 2019 14:22:51 -0500 From: Chris Burford To: Time Nuts Listings Subject: [time-nuts] Thunderbolt E Message-ID: <9165f782-88f7-d015-6a82-6102a4258...@austin.rr.com> Content-Type: text/plain; charset=utf-8; format=flowed I'm on the fence on purchasing a new Thunderbolt E from Trimble and wanted to hear from current or past owners. I have a couple of the eBay x-telecom patchwork quilt GPSDO units which seem to do an OK job. Is there anything else besides a warranty and better performance specs that the Thunderbolt offers? My intention is to use the Thunderbolt as a backup reference to my PRS10. Thanks. ___ 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] Thunderbolt E
Chris, i have one which I bought new several years ago. It had a failure under warranty where in the serial chip stopped doing its thing. The unit continued to lock to SVs and delivered 10MHz and the PPS. Took almost two months to be returned, where it worked fine until very recently. Same issue with the serial chip. Trimble quoted a price of $650 for repairs. Ouch. As they say "Other than that Mrs Lincoln, how did you enjoy the play...”, it played fine as long as you could talk to it. Antenna location is very important as is true for all timing GPS units. The fit is supplied with a good length of 75 Ohn coax, power supply, antenna, and some coas adapters. So the question is how much do you intend to spend? Lady Heather works great when the serial chip was still good. Jon KF5TFJ Re: Date: Thu, 11 Jul 2019 14:22:51 -0500 From: Chris Burford To: Time Nuts Listings Subject: [time-nuts] Thunderbolt E Message-ID: <9165f782-88f7-d015-6a82-6102a4258...@austin.rr.com> Content-Type: text/plain; charset=utf-8; format=flowed I'm on the fence on purchasing a new Thunderbolt E from Trimble and wanted to hear from current or past owners. I have a couple of the eBay x-telecom patchwork quilt GPSDO units which seem to do an OK job. Is there anything else besides a warranty and better performance specs that the Thunderbolt offers? My intention is to use the Thunderbolt as a backup reference to my PRS10. Thanks. ___ 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] Thunderbolt E
I'm not going to buy one, but . . . what does a new-from-Trimble Thunderbolt E cost? Steve, K8JQ On 7/11/2019 6:06 PM, Bob kb8tq wrote: Hi There is nothing on the spec sheet that leaps out as “obviously better” than the T-Bolt’s that we all know and love. Indeed you *will* get support, a warranty, and a unit that has 10 to 20 years less wear and tear. Bob On Jul 11, 2019, at 3:22 PM, Chris Burford wrote: I'm on the fence on purchasing a new Thunderbolt E from Trimble and wanted to hear from current or past owners. I have a couple of the eBay x-telecom patchwork quilt GPSDO units which seem to do an OK job. Is there anything else besides a warranty and better performance specs that the Thunderbolt offers? My intention is to use the Thunderbolt as a backup reference to my PRS10. Thanks. ___ 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] Thunderbolt E
Hi There is nothing on the spec sheet that leaps out as “obviously better” than the T-Bolt’s that we all know and love. Indeed you *will* get support, a warranty, and a unit that has 10 to 20 years less wear and tear. Bob > On Jul 11, 2019, at 3:22 PM, Chris Burford wrote: > > I'm on the fence on purchasing a new Thunderbolt E from Trimble and wanted to > hear from current or past owners. > > I have a couple of the eBay x-telecom patchwork quilt GPSDO units which seem > to do an OK job. Is there anything else besides a warranty and better > performance specs that the Thunderbolt offers? My intention is to use the > Thunderbolt as a backup reference to my PRS10. > > Thanks. > > > ___ > 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] Thunderbolt E
I'm on the fence on purchasing a new Thunderbolt E from Trimble and wanted to hear from current or past owners. I have a couple of the eBay x-telecom patchwork quilt GPSDO units which seem to do an OK job. Is there anything else besides a warranty and better performance specs that the Thunderbolt offers? My intention is to use the Thunderbolt as a backup reference to my PRS10. Thanks. ___ 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.
