Re: [time-nuts] Z3801A
Hi there Jose, Hmurray, how about this one? _http://www.jackson-labs.com/docs/Fury_Flyer.pdf_ (http://www.jackson-labs.com/docs/Fury_Flyer.pdf) It's available in double-oven version (SC-Cut Crystal) and single-oven AT-cut. Software compatible to the HP GPSDO's, but lot's better performance. bye, Said In a message dated 11/10/2006 13:22:52 Pacific Standard Time, [EMAIL PROTECTED] writes: > Unless you actually need portability, you might look for an HP Z3801 > or similar GPS-stabilized quartz standard. I haven't seen one on ebay for a while. Are they still available? Where? Is there a good alternate I should be considering? ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] Z3801A
Hi Rick, Jose, Hmurray, forgot to mention: the Fury unit only uses about 0.35A at 12V, and runs from 11V to 14V, so it can easily be run from a Pb battery, < 4.5W power consumption. 45min warmup time typ. with the double-oven OCXO. Better <100s Allan Deviation stability than the PRS10 SRS Rb standard. Allan Deviation of < 2E-14 with 18 hour averaging possible, see attached Allan Deviation plot (Vertical in Nanoseconds, double-oven OCXO). Basically that's the accuracy of it's internal M12+ Timing GPS. But now I am bragging. bye, Said AllanDev_LongTerm.pdf Description: Adobe PDF document ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
[time-nuts] What is UTC after all?
Looking at the Thunderbolt manual, I came across this: It is important to remember that any real-time UTC is actually a prediction of UTC. The official UTC time is published approximately one month after the fact. It makes sense that real-time "UTC" is a prediction, since UTC is the average of a number of clocks around the world, we can't know ahead of time what they are going to do, we can only guess. However, it is amazing to me that it takes a month to have the official time, which I guess is published in the form of an error from the predicted number. That reminds me when Motorola went after the Malcolm Baldridge award, they looked at their processes and someone noticed that while FedEx could deliver a piece of paper or hardware across the country overnight as long as you call them before 4:00 PM, it took Mot 9 weeks to issue a check for that transaction, which involved many more people than it took to carry the package. Here, we need a month to find out how many nanoseconds we were off... That's a lot of data to keep track off if you actually need the ultimate accuracy. I would not want to be the one counting nS for a month... Didier ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] FMT
Didier Juges said the following on 11/10/2006 10:05 PM: > Hi Mike, > > Interesting, I was just doing pretty much that, except that I did not > think of using the tracking generator of the 3586A as a reference, I > used an 8657B synthesizer phase locked to the Thunderbolt GPSDO to > inject a reference signal 20Hz above the test signal (I used WWV at 5 > MHz for test), so that I could display both signals at the same time in > the FFT using Spectrum Lab. Setting the two very close eliminates the > risk of selecting the wrong sideband and reduces the error caused by the > sound card sample rate being off. I've used the 3586 tracking generator trick for the last couple of years. It makes the tuning process much, much simpler because there's only one knob to twiddle. I usually use the 400Hz bandwidth in the receiver, and a window running a shallow FFT for quick response. The tracking generator signal will always show up at nominally 1850 Hz in the receiver passband (it may be a Hz or more off because the BFO is generated from a separate crystal and isn't locked to the reference). It stays put as the unknown signal moves with the tuning knob. So, look around 1850 Hz on the display, and tune so the unknown is maybe 50 Hz away from the tracking generator signal. Then take your measurement. It's important to have a good variable attenuator on the tracking generator line as you need to match its level pretty closely to the unknown signal level in order to get comparable amplitudes on the display. John ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
[time-nuts] New PLOTTER version / HP5065 Frequency processing part II
Hi folks, first i would like to announce a new version of PLOTTER which can be downloaded from www.ulrich-bangert.de The new version can classify data and compute new data columns from existing ones using a formula interpreter in that you may input a formula of your own. A lot of mathematic expressions are supported. Second, i would like to say thanks to anybody who answered on my "Frequency processing scheme of HP5065 rubidium vapour standard" thread. As usual in this group the (s+n)/n of the answers has been high. Nevertheless I dare to state that the basic question of mine is still unanswered. I believe that this is due to English not being my natural language so perhaps i did not manage to make the question really clear to everybody. Let me try again. Rubidium is NOT a PRIMARY frequency standard. Point. This has been well understood before I put forward my question and a lot of you have pointed to environmental parameters that may have a influence on the resonance frequency one may measure with a given physics package. The basic question has not been WHY the atomic resonance frequency is dependend on environmental parameters. The question has been TO WHAT EXTENT or expressed in other words IN WHICH ORDER OF MAGNITUDE these environmental parameters have an influence on the resonance frequency. This question has a very practical background: If you look at the schematics of a Ball-Efratom FRK-L rubidium standard you will notice that it has a fixed frequency synthesizer stage to generate the microwave frequency from the 10 MHz OCXO. There is NO possibility to tune anything concerning the microwave frequency of the physics package OTHER than the C-field setting. Since the C-field setting covers a frequency range of +/- 1E-9 relative this seems to be a strong indication that all efects that you decribe (including a exchange of the physics package) must be WELL below 10E-9 relative. With the resonance frequency in the 7 GHz region +/-10E-9 makes abt. +/- 7 Hz absolute. Note that this +/-7 Hz matches pretty much the way how the rubidium's frequency is usually specified as x.xx +/- 4 (7)Hz for example on TVB's pages. Up to this point I am in harmony with the world. Now comes the strange fact: HP's 5065 is equipped with a tuneable synthesizer to generate the microwave frequency from the OCXO. HP states that this tuneable synthesizer can be used to generate a number of different 'time scales' as some of you also have pointed at. I understand this very well! But the STRANGE thing is that HP uses DIFFERENT synthesizer settings albeit the intended purpose of the tuning ALSO to generate THE SAME time scale with two different physics packages. That is what we found on two different physics packages: Physics Package 1 C-Field 7.21 Synth. 8619 - 5.31498914 Mhz Physics Package 2 C-Field 8.24 Synth. 8397 - 5.31503431 Mhz Please note that the two synthesizer setting are different by MORE THAN 45 Hz. This is just one example, other physics packages may perhaps even be more apart. We have seen above that there is reason to believe that all environmental influences are smaller than +/-7 Hz. So where comes this 45 Hz difference from? Cheers Ulrich Bangert, DF6JB ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP5065 Frequency processing part II
At 6:03 PM +0100 11/11/06, Ulrich Bangert wrote: >Hi folks, > >If you look at the schematics of a Ball-Efratom FRK-L rubidium standard >you will notice that it has a fixed frequency synthesizer stage to >generate the microwave frequency from the 10 MHz OCXO. There is NO >possibility to tune anything concerning the microwave frequency of the >physics package OTHER than the C-field setting. Since the C-field >setting covers a frequency range of +/- 1E-9 relative this seems to be a >strong indication that all efects that you decribe (including a exchange >of the physics package) must be WELL below 10E-9 relative. With the >resonance frequency in the 7 GHz region +/-10E-9 makes abt. +/- 7 Hz >absolute. Note that this +/-7 Hz matches pretty much the way how the >rubidium's frequency is usually specified as x.xx +/- 4 (7)Hz for >example on TVB's pages. Up to this point I am in harmony with the world. Ulrich, The limits of rubidium oscillator operating range is larger than you have calculated. The unit I was trying to adjust had drifted outside the range of the C-field adjustment control. This drift occurred over 13 years of use in a laboratory environment. It was a total of approximately 1.5E-9 drift. The thing that can be changed to accommodate this drift is the factory selected resistors in the C-field setting control circuit. See R10 and R11 on board 3, the 20V supply board. I don't know what the maximum variability range is, but if it was less than 1E-9 then these resistors would not be factory selected. -- --David Forbes, Tucson, AZ http://www.cathodecorner.com/ ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] What is UTC after all?
In message: <[EMAIL PROTECTED]> Didier Juges <[EMAIL PROTECTED]> writes: : Here, we need a month to find out how many nanoseconds we were off... : That's a lot of data to keep track off if you actually need the ultimate : accuracy. I would not want to be the one counting nS for a month... UTC is the realization of time sources from around the world. I don't know if it still takes a month to publish the data, but I do know that the data is accumulated in files, and those files need to be sent to BIPM manually. I believe that there are efforts underway to harmonize the output format of the different timing systems to streamline the process... Warner ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
[time-nuts] Looking for manual....
I'm looking for a copy (paper or electronic) of a manual for an Austron 6016 Frequency Multiplier. Can anyone help? Thanks in advance, Brian, WA1ZMS ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] New PLOTTER version / HP5065 Frequency processing part II
From: "Ulrich Bangert" <[EMAIL PROTECTED]> Subject: [time-nuts] New PLOTTER version / HP5065 Frequency processing part II Date: Sat, 11 Nov 2006 18:03:50 +0100 Message-ID: <[EMAIL PROTECTED]> > Hi folks, Hi Ulrich, > Now comes the strange fact: HP's 5065 is equipped with a tuneable > synthesizer to generate the microwave frequency from the OCXO. HP states > that this tuneable synthesizer can be used to generate a number of > different 'time scales' as some of you also have pointed at. I > understand this very well! > > But the STRANGE thing is that HP uses DIFFERENT synthesizer settings > albeit the intended purpose of the tuning ALSO to generate THE SAME time > scale with two different physics packages. > > That is what we found on two different physics packages: > > Physics Package 1 C-Field 7.21 Synth. 8619 - 5.31498914 > Mhz > > Physics Package 2 C-Field 8.24 Synth. 8397 - 5.31503431 > Mhz > > Please note that the two synthesizer setting are different by MORE THAN > 45 Hz. This is just one example, other physics packages may perhaps even > be more apart. We have seen above that there is reason to believe that > all environmental influences are smaller than +/-7 Hz. So where comes > this 45 Hz difference from? Not sure this is going to help you, but: With the C-field trimming you may tune the resonance frequency and the frequency synthesizer may be set accordingly to acheive the same frequency. You should be able to adjust your synthesizer and then trim your C-field to acheive TAI/UTC pseudo-synchronisity. The different old rubidium implementations use different resonance synthesis step up relations and thus require different C-field strengths to acheive correct output frequency. Naturally toss in the frequency pulling correction for that individual physical package. If you have two HP 5065 rubidiums alongside, then set one of them up the same as the other, and then you should be able to trim it up on the C-field for propper frequency again. Cheers, Magnus ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] What is UTC after all?
> Looking at the Thunderbolt manual, I came across this: > > > It is important to remember that any real-time UTC is actually a > prediction of UTC. > The official UTC time is published approximately one month after the fact. > > > It makes sense that real-time "UTC" is a prediction, since UTC is the > average of a number of clocks around the world, we can't know ahead of > time what they are going to do, we can only guess. Didier, Remember it's all a matter of statistics. If you want 1 us or even 100 ns accuracy, it's much closer to "certainty" than a "guess". Any two clocks will drift apart, so time is always a sort of a guess. The key point is not if clocks agree, but how close they will be over some elapsed interval. Hence, the use of statistics like ADEV, or MTIE, etc. In a sense, every clock is a "prediction" and all of timing is a guess. The past and present phase and rate combine to create the future time, to some level of accuracy, with some probability. The measure of how well the past behavior of a clock is a prediction of future time is exactly what the Allan deviation measures. > However, it is amazing to me that it takes a month to have the official > time, which I guess is published in the form of an error from the > predicted number. Like a GPSDO, there is a crossover point where too frequent a correction is either not good or technically not even possible (due to inter-lab measurement noise or clock synthesizer granularity). I'm not sure where that point it; probably less than one month, to be sure. But don't think that updating the rate of the worlds clocks, like, every hour would be a good thing either. /tvb ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] New PLOTTER version / HP5065 Frequency processing part II
Ulrich Bangert wrote: > Hi folks, > > first i would like to announce a new version of PLOTTER which can be > downloaded from > > www.ulrich-bangert.de > > The new version can classify data and compute new data columns from > existing ones using a formula interpreter in that you may input a > formula of your own. A lot of mathematic expressions are supported. > > Second, i would like to say thanks to anybody who answered on my > "Frequency processing scheme of HP5065 rubidium vapour standard" thread. > As usual in this group the (s+n)/n of the answers has been high. > Nevertheless I dare to state that the basic question of mine is still > unanswered. I believe that this is due to English not being my natural > language so perhaps i did not manage to make the question really clear > to everybody. Let me try again. > > Rubidium is NOT a PRIMARY frequency standard. Point. This has been well > understood before I put forward my question and a lot of you have > pointed to environmental parameters that may have a influence on the > resonance frequency one may measure with a given physics package. > > The basic question has not been WHY the atomic resonance frequency is > dependend on environmental parameters. The question has been TO WHAT > EXTENT or expressed in other words IN WHICH ORDER OF MAGNITUDE these > environmental parameters have an influence on the resonance frequency. > > This question has a very practical background: > > If you look at the schematics of a Ball-Efratom FRK-L rubidium standard > you will notice that it has a fixed frequency synthesizer stage to > generate the microwave frequency from the 10 MHz OCXO. There is NO > possibility to tune anything concerning the microwave frequency of the > physics package OTHER than the C-field setting. Since the C-field > setting covers a frequency range of +/- 1E-9 relative this seems to be a > strong indication that all efects that you decribe (including a exchange > of the physics package) must be WELL below 10E-9 relative. With the > resonance frequency in the 7 GHz region +/-10E-9 makes abt. +/- 7 Hz > absolute. Note that this +/-7 Hz matches pretty much the way how the > rubidium's frequency is usually specified as x.xx +/- 4 (7)Hz for > example on TVB's pages. Up to this point I am in harmony with the world. > > Now comes the strange fact: HP's 5065 is equipped with a tuneable > synthesizer to generate the microwave frequency from the OCXO. HP states > that this tuneable synthesizer can be used to generate a number of > different 'time scales' as some of you also have pointed at. I > understand this very well! > > But the STRANGE thing is that HP uses DIFFERENT synthesizer settings > albeit the intended purpose of the tuning ALSO to generate THE SAME time > scale with two different physics packages. > > That is what we found on two different physics packages: > > Physics Package 1 C-Field 7.21 Synth. 8619 - 5.31498914 > Mhz > > Physics Package 2 C-Field 8.24 Synth. 8397 - 5.31503431 > Mhz > > Please note that the two synthesizer setting are different by MORE THAN > 45 Hz. This is just one example, other physics packages may perhaps even > be more apart. We have seen above that there is reason to believe that > all environmental influences are smaller than +/-7 Hz. So where comes > this 45 Hz difference from? > > Cheers > > Ulrich Bangert, DF6JB > > > ___ > time-nuts mailing list > time-nuts@febo.com > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > Ulrich The manual for the SRS PRS10 states that the combined effects of the buffer gas and the pump lamp spectral profile shift the resonance about 3kHz from the unperturbed natural transition frequency. With a different buffer gas, lamp spectral profile, or buffer gas pressure the resonance shift will be different for different physics packages. Perhaps Efratom relied on the reproducibility of lamp characteristics, buffer gas pressure, buffer gas composition during the manufacturing process whilst HP allowed for variations in these parameters from one physics package to another. Bruce ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] HP5065 Frequency processing part II
David, what you are saying, is it not more or less a patronage of my claim? Because the factory selected resistors have surely be selected in a way that tuning the frequency setpoint is possible in the sense a) you have a fine enough tuning resolution to get the job done with your fingers and b) the setpoint is always within the tuning range. When the Ball-Efratom people decided to make the tuning range +/-10E-9 and used a 25 turn precision trimmer for that I understand it as an good compromise between a) and b). If you have an single unit that has changed more than 10E-9 over the years I would think that this one is the outlier that is always possible. But in general they thought that +/-10E-9 was more than needed over the lifetime. Cheers Ulrich Bangert > -Ursprüngliche Nachricht- > Von: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Im Auftrag von David Forbes > Gesendet: Samstag, 11. November 2006 18:27 > An: Discussion of precise time and frequency measurement > Betreff: Re: [time-nuts] HP5065 Frequency processing part II > > > At 6:03 PM +0100 11/11/06, Ulrich Bangert wrote: > >Hi folks, > > > >If you look at the schematics of a Ball-Efratom FRK-L > rubidium standard > >you will notice that it has a fixed frequency synthesizer stage to > >generate the microwave frequency from the 10 MHz OCXO. There is NO > >possibility to tune anything concerning the microwave > frequency of the > >physics package OTHER than the C-field setting. Since the C-field > >setting covers a frequency range of +/- 1E-9 relative this > seems to be > >a strong indication that all efects that you decribe (including a > >exchange of the physics package) must be WELL below 10E-9 relative. > >With the resonance frequency in the 7 GHz region +/-10E-9 makes abt. > >+/- 7 Hz absolute. Note that this +/-7 Hz matches pretty > much the way > >how the rubidium's frequency is usually specified as x.xx +/- 4 > >(7)Hz for example on TVB's pages. Up to this point I am in > harmony with > >the world. > > Ulrich, > > The limits of rubidium oscillator operating range is larger than you > have calculated. > > The unit I was trying to adjust had drifted outside the range of the > C-field adjustment control. This drift occurred over 13 years of use > in a laboratory environment. It was a total of approximately 1.5E-9 > drift. > > The thing that can be changed to accommodate this drift is the > factory selected resistors in the C-field setting control circuit. > See R10 and R11 on board 3, the 20V supply board. > > I don't know what the maximum variability range is, but if it was > less than 1E-9 then these resistors would not be factory selected. > -- > > --David Forbes, Tucson, AZ > http://www.cathodecorner.com/ > > ___ > time-nuts mailing list > time-nuts@febo.com > https://www.febo.com/cgi-> bin/mailman/listinfo/time-nuts > ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
Re: [time-nuts] New PLOTTER version / HP5065 Frequency processing part II
Bruce, > The manual for the SRS PRS10 states that the combined effects of the > buffer gas and the pump lamp spectral profile shift the > resonance about 3kHz from the unperturbed natural transition frequency. Ok, this is a word! > Perhaps Efratom relied on the reproducibility of lamp characteristics, > buffer gas pressure, buffer gas composition during the manufacturing > process whilst HP allowed for variations in these parameters > from one physics package to another. This has been one of the original ideas! Basically this thread has been started to find out whether the physics of an rubidium standard would allow for such an idea. Cheers Ulrich > -Ursprüngliche Nachricht- > Von: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Im Auftrag von Dr Bruce Griffiths > Gesendet: Sonntag, 12. November 2006 00:55 > An: Discussion of precise time and frequency measurement > Betreff: Re: [time-nuts] New PLOTTER version / HP5065 > Frequency processing part II > > > Ulrich Bangert wrote: > > Hi folks, > > > > first i would like to announce a new version of PLOTTER > which can be > > downloaded from > > > > www.ulrich-bangert.de > > > > The new version can classify data and compute new data columns from > > existing ones using a formula interpreter in that you may input a > > formula of your own. A lot of mathematic expressions are supported. > > > > Second, i would like to say thanks to anybody who answered on my > > "Frequency processing scheme of HP5065 rubidium vapour standard" > > thread. As usual in this group the (s+n)/n of the answers has been > > high. Nevertheless I dare to state that the basic question > of mine is > > still unanswered. I believe that this is due to English not > being my > > natural language so perhaps i did not manage to make the question > > really clear to everybody. Let me try again. > > > > Rubidium is NOT a PRIMARY frequency standard. Point. This has been > > well understood before I put forward my question and a lot > of you have > > pointed to environmental parameters that may have a > influence on the > > resonance frequency one may measure with a given physics package. > > > > The basic question has not been WHY the atomic resonance > frequency is > > dependend on environmental parameters. The question has > been TO WHAT > > EXTENT or expressed in other words IN WHICH ORDER OF > MAGNITUDE these > > environmental parameters have an influence on the resonance > frequency. > > > > This question has a very practical background: > > > > If you look at the schematics of a Ball-Efratom FRK-L rubidium > > standard you will notice that it has a fixed frequency synthesizer > > stage to generate the microwave frequency from the 10 MHz > OCXO. There > > is NO possibility to tune anything concerning the microwave > frequency > > of the physics package OTHER than the C-field setting. Since the > > C-field setting covers a frequency range of +/- 1E-9 relative this > > seems to be a strong indication that all efects that you decribe > > (including a exchange of the physics package) must be WELL > below 10E-9 > > relative. With the resonance frequency in the 7 GHz region +/-10E-9 > > makes abt. +/- 7 Hz absolute. Note that this +/-7 Hz matches pretty > > much the way how the rubidium's frequency is usually specified as > > x.xx +/- 4 (7)Hz for example on TVB's pages. Up to this > point I am > > in harmony with the world. > > > > Now comes the strange fact: HP's 5065 is equipped with a tuneable > > synthesizer to generate the microwave frequency from the OCXO. HP > > states that this tuneable synthesizer can be used to > generate a number > > of different 'time scales' as some of you also have pointed at. I > > understand this very well! > > > > But the STRANGE thing is that HP uses DIFFERENT synthesizer > settings > > albeit the intended purpose of the tuning ALSO to generate THE SAME > > time scale with two different physics packages. > > > > That is what we found on two different physics packages: > > > > Physics Package 1 C-Field 7.21 Synth. 8619 - > 5.31498914 > > Mhz > > > > Physics Package 2 C-Field 8.24 Synth. 8397 - > 5.31503431 > > Mhz > > > > Please note that the two synthesizer setting are different by MORE > > THAN 45 Hz. This is just one example, other physics packages may > > perhaps even be more apart. We have seen above that there > is reason to > > believe that all environmental influences are smaller than > +/-7 Hz. So > > where comes this 45 Hz difference from? > > > > Cheers > > > > Ulrich Bangert, DF6JB > > > > > > ___ > > time-nuts mailing list > > time-nuts@febo.com > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > > > > Ulrich > > The manual for the SRS PRS10 states that the combined effects of the > buffer gas and the pump lamp spectral profile shift the > resonance about > 3kHz from the unperturb
