[time-nuts] Re: What's the best HP OCXO for frequency counter reference?
OCXOs generally don’t require a lot of power. A small (portable size) UPS can keep the OCXO powered up while on the move. With an appropriate inverter, the UPS can be powered by a vehicle. Think “flying clock” of years ago. On Tue, Jun 28, 2022 at 3:59 PM Bob kb8tq via time-nuts < time-nuts@lists.febo.com> wrote: > Hi > > > > On Jun 28, 2022, at 12:15 PM, Hal Murray via time-nuts < > time-nuts@lists.febo.com> wrote: > > > > > > Adrian Godwin said: > >> If you use the ovened oscillator for temporary use away from the home > GPSDO, > >> how good will the oscillator be with those interruptions to power / > >> temperature, and will it stabilise during the period you're using it > there ? > > > > You can solve that with a UPS and/or a gizmo that plugs into a car > accessory > > socket. > > You still power it down doing that. Power cycle generally isn’t a good > idea if you > are after good stability. > > > > > How much does the mechanical jostling as gear gets moved from bench to > car to > > table effect the frequency? > > If you flip it end for end you might be measuring the “2g tip” > acceleration sensitivity :). > That could be up in the 1 to 2 ppb range. Shock and vibe is very much a > “that depends” > sort of thing. You could (but probably won’t) see a couple of ppb. > > The biggest issue is going to be the changing temperature environment. > Thermal shock > is going to create a bigger change than simple temperature change. Going > from inside > to outside to car to outside to inside …. each one is a relatively fast > change. You might > have a device that held a ppb in a normal temp test and it changes 10X > that (or more) > when hit with a relatively modest “fast change”. > > Just what’s fast and how much of a change you get is very much a “that > depends” sort > of thing. Leave the cover off your OCXO mechanical trimmer and you could > find that it > is very sensitive to a gentle gust of wind from the wrong direction …. > > Bob > > > > > > > -- > > These are my opinions. I hate spam. > > > > > > ___ > > time-nuts mailing list -- time-nuts@lists.febo.com > > To unsubscribe send an email to time-nuts-le...@lists.febo.com > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-le...@lists.febo.com -- Jeremy Nichols Sent from my iPad 6. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-le...@lists.febo.com
[time-nuts] Re: What's the best HP OCXO for frequency counter reference?
Hi > On Jun 28, 2022, at 12:15 PM, Hal Murray via time-nuts > wrote: > > > Adrian Godwin said: >> If you use the ovened oscillator for temporary use away from the home GPSDO, >> how good will the oscillator be with those interruptions to power / >> temperature, and will it stabilise during the period you're using it there ? > > You can solve that with a UPS and/or a gizmo that plugs into a car accessory > socket. You still power it down doing that. Power cycle generally isn’t a good idea if you are after good stability. > > How much does the mechanical jostling as gear gets moved from bench to car to > table effect the frequency? If you flip it end for end you might be measuring the “2g tip” acceleration sensitivity :). That could be up in the 1 to 2 ppb range. Shock and vibe is very much a “that depends” sort of thing. You could (but probably won’t) see a couple of ppb. The biggest issue is going to be the changing temperature environment. Thermal shock is going to create a bigger change than simple temperature change. Going from inside to outside to car to outside to inside …. each one is a relatively fast change. You might have a device that held a ppb in a normal temp test and it changes 10X that (or more) when hit with a relatively modest “fast change”. Just what’s fast and how much of a change you get is very much a “that depends” sort of thing. Leave the cover off your OCXO mechanical trimmer and you could find that it is very sensitive to a gentle gust of wind from the wrong direction …. Bob > > > -- > These are my opinions. I hate spam. > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-le...@lists.febo.com ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-le...@lists.febo.com
[time-nuts] Re: What's the best HP OCXO for frequency counter reference?
Adrian Godwin said: > If you use the ovened oscillator for temporary use away from the home GPSDO, > how good will the oscillator be with those interruptions to power / > temperature, and will it stabilise during the period you're using it there ? You can solve that with a UPS and/or a gizmo that plugs into a car accessory socket. How much does the mechanical jostling as gear gets moved from bench to car to table effect the frequency? -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-le...@lists.febo.com
[time-nuts] Re: What's the best HP OCXO for frequency counter reference?
Hi All HP 10811’s came off the same line and with the exception of the “weird” one used in the original HP GPSDO, they all had the same parts / same optimizations in them. The only thing that was done to make this or that dash number was to screen the finished units. Once “enough” of this or that spec came out of screening, they stopped looking. The “next one in line” might have well beat any of the ones in the batch … they simply had no time ( = funds ) to screen everything. Since this screening was done a *long* time ago, there is no way to know if the OCXO you have still is a “good one”. Stuff happens over time …. subtle changes rarely get noticed. Bob > On Jun 28, 2022, at 12:03 PM, Dr. David Kirkby > wrote: > > On Tue, 28 Jun 2022 at 20:04, Bob kb8tq via time-nuts > mailto:time-nuts@lists.febo.com>> wrote: > Hi > > The “typical” 10811 struggles when shut down for a while. Once the oven > is turned off, the boards are just sitting there in whatever environment your > lab provides. Do they soak up humidity or is it something else? We could > (and have) debated that quite a bit. > > Part of my problem is that if I ever wanted to sell this, I'd like to sell it > with an oven that was designed to meet the specifications given in the > frequency counter manual for option 010, which are better than the 10811A. > > Another quite practical issue is setting the blinking frequency, as the pot > on the oscillator seems too touchy. I set a signal generator to 20 GHz, which > was fed from a GPS frequency reference. The output of the signal generator > was then fed into the counter. Getting the counter to read within 100 Hz is > extremely difficult, as the tuning control is too coarse. As I write the > frequency counter is reading 83 Hz higher than 20 GHz. > > To be honest, that's "good enough" for what I am practically going to need. > But I would like to do better if possible. > > Dave ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-le...@lists.febo.com
[time-nuts] Re: What's the best HP OCXO for frequency counter reference?
On Tue, 28 Jun 2022 at 20:04, Bob kb8tq via time-nuts < time-nuts@lists.febo.com> wrote: > Hi > > The “typical” 10811 struggles when shut down for a while. Once the oven > is turned off, the boards are just sitting there in whatever environment > your > lab provides. Do they soak up humidity or is it something else? We could > (and have) debated that quite a bit. > Part of my problem is that if I ever wanted to sell this, I'd like to sell it with an oven that was designed to meet the specifications given in the frequency counter manual for option 010, which are better than the 10811A. Another quite practical issue is setting the blinking frequency, as the pot on the oscillator seems too touchy. I set a signal generator to 20 GHz, which was fed from a GPS frequency reference. The output of the signal generator was then fed into the counter. Getting the counter to read within 100 Hz is extremely difficult, as the tuning control is too coarse. As I write the frequency counter is reading 83 Hz higher than 20 GHz. To be honest, that's "good enough" for what I am *practically* going to need. But I would like to do better if possible. Dave ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-le...@lists.febo.com
[time-nuts] Re: What's the best HP OCXO for frequency counter reference?
Hi The “typical” 10811 struggles when shut down for a while. Once the oven is turned off, the boards are just sitting there in whatever environment your lab provides. Do they soak up humidity or is it something else? We could (and have) debated that quite a bit. Regardless of what the issue is, the bottom line is that when you turn the beast back on again, it *might* take quite a while for it to become reasonably good. In some cases that means a couple weeks to hit spec limits. In others it might mean a week or two to get back to “as good as it was”. A *good* 10811 will do much better than what the specs would suggest. It may be a “one in a hundred” sort of item, but they do exist. Ones that barely / don’t meet spec (even after a month on power) also exist and they are a lot more common than the ones we brag about with various plots. What’s the point? Keeping the unit on power is a good idea, even if you have a good example. Keeping a poor one on power still will not turn it into a good one. Checking out the units you have is a “needed thing” before you start counting on them for this or that. They *all* left the factory a *long* while ago. It *does* matter just what you are counting on the OCXO to do. Does phase noise at 100 KHz offset matter in your case? Does 10 second ADEV at 5x10^-12 degrade your performance compared to 5x10^-13? Is drift the only thing that really matters? ( and when did you last set it on? :) :) ) If so, temperature stability (in a “transport someplace” situation) likely also matters, testing it is not something most are set up to properly do …. One alternative: Grab a fairly typical telecom Rb. Put a (cheap) cleanup oscillator on it. Use that as your “portable” reference. Run it on batteries (or a 12V plug in the car) as you transport this or that item here or there. Let it sit unpowered on the shelf until about a week ahead of your planned expedition. Fun !!! Bob > On Jun 28, 2022, at 9:20 AM, Adrian Godwin via time-nuts > wrote: > > Related to that .. > > If you use the ovened oscillator for temporary use away from the home > GPSDO, how good will the oscillator be with those interruptions to power / > temperature, and will it stabilise during the period you're using it there ? > > I don't know what the vales are, but I'd suggest the option 010 will never > reach the 001's spec and the 001 may not even be justified. > > > > On Tue, Jun 28, 2022 at 6:13 PM Dr. David Kirkby via time-nuts < > time-nuts@lists.febo.com> wrote: > >> I have a 5352B 40 GHz frequency counter which was fitted with a TCXO. I >> removed that and fitted an HP 10811-60111 S/N 2332A17049 which I removed >> from a 5370B time interval counter - I have a few of those, and the >> microwave frequency counter needed the oven more than the time-interval >> counter. >> >> Looking at the specification of the 5352B, there were 3 oscillator options >> >> * Standard TCXO >> * Option 001 Oven time based. Long-term aging < 5 x 10^-10 / day after 24 >> hour warmup. < 1 x 10^-7 / year for continuous operation. >> * Option 010 High stability time base. Long term aging < 1 x 10^-10 / day. >> < 3.6 x 10^-8 / year for continuous operation. >> >> To be honest, when the instrument is here, I will use a GPS reference. But >> I might want to take it to the amateur radio club sometimes. I would like >> to get the best oscillator I can. Are any models going to be better than >> others, or by this time, is it just pot luck? I think it's the latter, but >> maybe some are double-ovens and some single. >> >> With the exception of power cuts of up to a few hours, the HP 10811-60111 I >> fitted has been continuously powered on for a few years. But due to soaring >> power costs, I am going to switch my ovens off. >> >> Dr David Kirkby Ph.D >> Email: drkir...@kirkbymicrowave.co.uk Web: >> https://www.kirkbymicrowave.co.uk/ >> Kirkby Microwave Ltd (Tel 01621-680100 / +44 1621-680100) >> Stokes Hall Lodge, Burnham Rd, Chelmsford, Essex, CM3 6DT. >> ___ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe send an email to time-nuts-le...@lists.febo.com >> > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-le...@lists.febo.com ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-le...@lists.febo.com
[time-nuts] Re: What's the best HP OCXO for frequency counter reference?
David Great comment on power. I used to run everything 24 X 7 also including various radio sets. That was all fine when Mr. Ready Killowatt (Believe he worked at a Nuclear Power plant) was 2-3 cents a KW and the only other charge was a meter rental. But then the darn rates started going up. Now I have a GPDSO with TCXO with distribution. Power switches on everything. I can switch better GPDSOs into the distribution chain if needed. Same with CS and Rb references. But 99% of the time the TCXO is good enough even from a cold start. That system when on as I recall is maybe 4 watts. Its not a lot. I think you nailed it on what may be available in the wild. Hard to say how good or bad something is. Some sellers will let you check within 30 days. The question is how good does it have to be to take to a club meeting? Regards Paul WB8TSL On Tue, Jun 28, 2022 at 1:13 PM Dr. David Kirkby via time-nuts < time-nuts@lists.febo.com> wrote: > I have a 5352B 40 GHz frequency counter which was fitted with a TCXO. I > removed that and fitted an HP 10811-60111 S/N 2332A17049 which I removed > from a 5370B time interval counter - I have a few of those, and the > microwave frequency counter needed the oven more than the time-interval > counter. > > Looking at the specification of the 5352B, there were 3 oscillator options > > * Standard TCXO > * Option 001 Oven time based. Long-term aging < 5 x 10^-10 / day after 24 > hour warmup. < 1 x 10^-7 / year for continuous operation. > * Option 010 High stability time base. Long term aging < 1 x 10^-10 / day. > < 3.6 x 10^-8 / year for continuous operation. > > To be honest, when the instrument is here, I will use a GPS reference. But > I might want to take it to the amateur radio club sometimes. I would like > to get the best oscillator I can. Are any models going to be better than > others, or by this time, is it just pot luck? I think it's the latter, but > maybe some are double-ovens and some single. > > With the exception of power cuts of up to a few hours, the HP 10811-60111 I > fitted has been continuously powered on for a few years. But due to soaring > power costs, I am going to switch my ovens off. > > Dr David Kirkby Ph.D > Email: drkir...@kirkbymicrowave.co.uk Web: > https://www.kirkbymicrowave.co.uk/ > Kirkby Microwave Ltd (Tel 01621-680100 / +44 1621-680100) > Stokes Hall Lodge, Burnham Rd, Chelmsford, Essex, CM3 6DT. > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-le...@lists.febo.com > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-le...@lists.febo.com
[time-nuts] Re: What's the best HP OCXO for frequency counter reference?
Related to that .. If you use the ovened oscillator for temporary use away from the home GPSDO, how good will the oscillator be with those interruptions to power / temperature, and will it stabilise during the period you're using it there ? I don't know what the vales are, but I'd suggest the option 010 will never reach the 001's spec and the 001 may not even be justified. On Tue, Jun 28, 2022 at 6:13 PM Dr. David Kirkby via time-nuts < time-nuts@lists.febo.com> wrote: > I have a 5352B 40 GHz frequency counter which was fitted with a TCXO. I > removed that and fitted an HP 10811-60111 S/N 2332A17049 which I removed > from a 5370B time interval counter - I have a few of those, and the > microwave frequency counter needed the oven more than the time-interval > counter. > > Looking at the specification of the 5352B, there were 3 oscillator options > > * Standard TCXO > * Option 001 Oven time based. Long-term aging < 5 x 10^-10 / day after 24 > hour warmup. < 1 x 10^-7 / year for continuous operation. > * Option 010 High stability time base. Long term aging < 1 x 10^-10 / day. > < 3.6 x 10^-8 / year for continuous operation. > > To be honest, when the instrument is here, I will use a GPS reference. But > I might want to take it to the amateur radio club sometimes. I would like > to get the best oscillator I can. Are any models going to be better than > others, or by this time, is it just pot luck? I think it's the latter, but > maybe some are double-ovens and some single. > > With the exception of power cuts of up to a few hours, the HP 10811-60111 I > fitted has been continuously powered on for a few years. But due to soaring > power costs, I am going to switch my ovens off. > > Dr David Kirkby Ph.D > Email: drkir...@kirkbymicrowave.co.uk Web: > https://www.kirkbymicrowave.co.uk/ > Kirkby Microwave Ltd (Tel 01621-680100 / +44 1621-680100) > Stokes Hall Lodge, Burnham Rd, Chelmsford, Essex, CM3 6DT. > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-le...@lists.febo.com > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-le...@lists.febo.com
