Re: [time-nuts] Question about frequency counter testing
Hi Oleg,
On 06/06/2018 02:53 PM, Oleg Skydan wrote:
> Hi, Magnus!
>
> Sorry for the late answer, I injured my left eye last Monday, so had
> very limited abilities to use computer.
Sorry to hear that. Hope you heal up well and quick enough.
> From: "Magnus Danielson"
>> As long as the sums C and D becomes correct, your
>> path to it can be whatever.
>
> Yes. It produces the same sums.
>
>> Yes please do, then I can double check it.
>
> I have write a note and attached it. The described modifications to the
> original method were successfully tested on my experimental HW.
You should add the basic formula
x_{N_1+n} = x_{N_1} + x_n^0
prior to (5) and explain that the expected phase-ramp within the block
will have a common offset in x_{N-1} and that the x_n^0 series is the
series of values with the offset removed from the series. This is fine,
it should just be introduced before applied on (5).
Notice that E as introduced in (8) and (9) is not needed, as you can
directly convert it into N(N_2-1)/2.
Anyway, you have sure understood the toolbox given to you, and your
contribution is to play the same game, but to reduce the needed dynamics
of the blocks. Neat. I may include that with due reference.
>> Yeah, now you can move your harware focus on considering interpolation
>> techniques beyond the processing power of least-square estimation, which
>> integrate noise way down.
>
> If you are talking about adding traditional HW interpolation of the
> trigger events I have no plans to do it. It is not possible to do it
> keeping 2.5ns base counter resolution (there is no way to output 400MHz
> clock signal out of the chip) and I do not want to add extra complexity
> to the HW of this project.
>
> But, the HW I use can simultaneously sample up to 10 timestamps. So, I
> can push the one shoot resolution down to 250ps using several delay
> lines (theoretically). I do not think that going down to 250ps has much
> sense (also I have another plans for that additional HW), but 2x or 4x
> one shot resolution improvement (down to 1.25ns or 625ps) is relatively
> simple to implement in HW and should be a good idea to try.
Sounds fun!
>>> I will probably throw out the power hungry and expensive SDRAM chip or
>>> use much smaller one :).
>>
>> Yeah, it would only be if you build multi-tau PDEV plots that you would
>> need much memory, other than that it is just buffer memory to buffer
>> before it goes to off-board processing, at which time you would need to
>> convey the C, D, N and tau0 values.
>
> Yes, I want to produce multi-tau PDEV plots :).
Make good sense. :)
> They can be computed with small memory footprint, but it will be non
> overlapped PDEVs, so the confidence level at large taus will be poor
> (with the practical durations of the measurements). I have a working
> code that realizes such algorithm. It uses only 272bytes of memory for
> each decade (1-2-5 values).
Seems very reasonable. If you are willing to use more memory, you can do
overlapping once decimated down to suitable rate. On the other hand,
considering the rate of samples, lots of gain already there.
> I need to think how to do the overlapping PDEV calculations with minimal
> memory/processing power requirements (I am aware that decimation
> routines should not use the overlapped calculations).
It's fairly simple, as you decimate samples and/or blocks, the produced
blocks overlaps one way or another. The multiple overlap variants should
each behave as a complete PDEV stream, and the variances can then be
added safely.
> BTW, are there any "optimal overlapping"? Or I should just use as much
> data as I can process?
"optimal overlapping" would be when all overlapping variants is used,
that is all with tau0 offsets available. When done for Allan Deviation
some refer to this as OADEV. This is however an misnomer as it is an
ADEV estimator which just has better confidence intervals than the
non-overlapping ADEV estimator. Thus, both estimator algorithms have the
same scale of measure, that of ADEV, but different amount of Equivalent
Degrees of Freedom (EDF) which has direct implications on the confidence
interval bounds. The more EDF, the better confidence interval. The more
overlapping, the more EDF. Further improvements would be TOTAL ADEV and
Theo, which both aim to squeeze out as much EDF as possible from the
dataset, in an attempt of reducing the length of measurement.
>> Please report on that progress! Sounds fun!
>
> I will drop a note when I will move on the next step. The things are a
> bit slower now.
Take care. Heal up properly. It's a hobby after all. :)
Good work there.
Cheers,
Magnus
> Thanks!
> Oleg
>
>
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>
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[time-nuts] Question about Lady Heather millisecond display
That is exactly what it should be doing... it shows the time of arrival of the receiver time message is varying by around a millisecond. --- > However, when entering this command the three millisecond digits do appear but only alternate back and forth every several seconds between "052" and "053". ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] [volt-nuts] febo.com Mailing List Changes
John, thanks for all you’ve done in the past. Regards, Jerry NK6P > On Jun 6, 2018, at 11:17 AM, John Ackermann N8UR wrote: > > Some of you may know that febo.com lives on leased hardware at a data center. > That hardware is now at its end of service life, which means it won't be > supported if it breaks. After pondering the options for a replacement, I've > decided that it's time to move away from dedicated hardware toward > cloud-based services, and to offload some of the sysadmin responsibilities to > people who know what they are doing. > > As part of that, the febo.com mailing lists will be moving to a new list > hosting provider. I'm working to make the transition as seamless as > possible. You will not need to resubscribe to the mailing lists, or change > any list settings. The lists will continue to use the Mailman software and > web interface, and will work just as they have been. > > However, the address for posting messages will change. Instead of sending > to, for example, "time-nuts@febo.com" you'll now send to > "time-n...@lists.febo.com" -- just adding "lists." to the domain. > > The new addresses should be working now. On June 15, the old addresses will > stop working; all postings after that date need to be to > @lists.febo.com. > > Around July 1, the lists will move to the new hosting company. We will > probably turn the lists off for a day or two during that transition, and I'll > send a note when that is about to happen. When the lists come back, you > should see no further changes. > > A note about the list archives, which have been accessible by going to, for > example, "https://www.febo.com/pipermail/time-nuts;, and which Google does a > pretty good job of indexing. Going forward, the archive URL will change as > well, using the lists.febo.com domain. That may impact search results until > Google indexes the new site. I'll maintain the existing archives as of the > cutover date at the old URL to mitigate the problem. Between June 15 and > July 1, archive access may be a bit flaky. > > This change will improve the reliability of the mailing lists, and remove > several single points of failure. It should allow the lists to continue > indefinitely into the future. I hope that the transition doesn't cause you > too much inconvenience. If you have any questions or concerns, please > contact me directly at j...@febo.com. > > John Ackermann > Your SysAdmin > ___ > volt-nuts mailing list -- volt-n...@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] febo.com Mailing List Changes
Some of you may know that febo.com lives on leased hardware at a data center. That hardware is now at its end of service life, which means it won't be supported if it breaks. After pondering the options for a replacement, I've decided that it's time to move away from dedicated hardware toward cloud-based services, and to offload some of the sysadmin responsibilities to people who know what they are doing. As part of that, the febo.com mailing lists will be moving to a new list hosting provider. I'm working to make the transition as seamless as possible. You will not need to resubscribe to the mailing lists, or change any list settings. The lists will continue to use the Mailman software and web interface, and will work just as they have been. However, the address for posting messages will change. Instead of sending to, for example, "time-nuts@febo.com" you'll now send to "time-n...@lists.febo.com" -- just adding "lists." to the domain. The new addresses should be working now. On June 15, the old addresses will stop working; all postings after that date need to be to @lists.febo.com. Around July 1, the lists will move to the new hosting company. We will probably turn the lists off for a day or two during that transition, and I'll send a note when that is about to happen. When the lists come back, you should see no further changes. A note about the list archives, which have been accessible by going to, for example, "https://www.febo.com/pipermail/time-nuts;, and which Google does a pretty good job of indexing. Going forward, the archive URL will change as well, using the lists.febo.com domain. That may impact search results until Google indexes the new site. I'll maintain the existing archives as of the cutover date at the old URL to mitigate the problem. Between June 15 and July 1, archive access may be a bit flaky. This change will improve the reliability of the mailing lists, and remove several single points of failure. It should allow the lists to continue indefinitely into the future. I hope that the transition doesn't cause you too much inconvenience. If you have any questions or concerns, please contact me directly at j...@febo.com. John Ackermann Your SysAdmin ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Question about Lady Heather millisecond display
Hello, Time-Nutters I recently updated an old version of Lady Heather that has been running well 24/7/365 for a number of years (except during prolonged power grid outages !). V5.0 is now installed and running. Getting it to display full-screen takes a bit of fiddling with different commands but otherwise seems to be running OK. I do have a number of questions about V5.0 but one I am focusing on at the moment is the command to enable the millisecond digits for the time display. The info I have says this is done by entering the /TSZ command. However, when entering this command the three millisecond digits do appear but only alternate back and forth every several seconds between "052" and "053". What might I be doing wrong? Any suggestions on how to make the millisecond digits count and sequence correctly? Thanks for any suggestions on resolving this issue !! Mike Baker Micanopy, FL * ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Raw phase data of super-5065
HI > On Jun 6, 2018, at 2:18 AM, tim...@timeok.it wrote: > > Hi, > > certainly the environmental effects are significant and it is precisely for > this reason that > acquisitions have been made simultaneously on two 5065, one modified and the > other not. > > To verify the results the same measures were taken with another pair of 5065, > one modified and the other not. > This second test was carried out at another site 300Km from the first one. > > Both tests showed a better and more consistent medium/long term ADEV than the > unmodified HP5065A. > > I want to clarify that these measures have the objective of verifying the > medium / long term stability and not the short term stability of the Super > version I agree it is improved.. > > Luciano Since my basement does one set of things ( temperature / humidity / pressure ) and somebody else runs in the garage ( different temperature / humidity / pressure) the data will be very specific to a single set of environmental conditions. Temperature is relatively easy to monitor, humidity and pressure are a bit more complex. At least logging them so people can compare your setting to there’s does need to be part of the process. Bob > > > > Da "Bob kb8tq" kb...@n1k.org > A "Luciano Paramithiotti" tim...@timeok.it,"Discussion of precise time and > frequency measurement" time-nuts@febo.com > Cc > Data Tue, 5 Jun 2018 10:05:34 -0400 > Oggetto Re: [time-nuts] Raw phase data of super-5065 > > Hi > > It is pretty well known that without “help” ( beyond the filter stuff on the > super) the 5065 has fairly poor temperature > stability and somewhat variable response to pressure and humidity. Taking two > samples right off the production line > likely would have given you different long term data as a result. > > If you are going to the trouble of watching these devices for a long time, > monitor temperature, pressure and humidity. > I suspect you will find correlations …. > > Bob > > > On Jun 5, 2018, at 5:44 AM, tim...@timeok.it wrote: > > > > > > Hi Attila, > > I am doing the long therm stability test on a couple of HP5065, one > > original A type, the second B or "super" compared with my best long therm > > stability, a GPSDO HPz3816A. > > This test will be 30 days long. It is a second test, with a second couple > > of HP5065A/B, to verify the long therm stability of both the version. > > > > Up to now the data available for version B or "super" only concerned the > > improvement of phase noise. > > > > From the first results it seems that the HP5065A is more stable within > > 30days than the modified version with the filter. > > It must be considered that the short-term stability of 5065 is better than > > the GPSDO / TICC up to 10-80k sec then, in this test configuration the > > valid data will be beyond these values. > > The results will be ready within 28 days and I will be happy to share them > > in order to have everyone's opinion. > > Regards, > > Luciano > > > > > > Da "time-nuts" time-nuts-boun...@febo.com > > A "Discussion of precise time and frequency measurement" time-nuts@febo.com > > Cc > > Data Mon, 4 Jun 2018 10:11:50 +0200 > > Oggetto [time-nuts] Raw phase data of super-5065 > > Hoi zäme! > > > > Would one (preferably multiple) of the owners of a super-5065 be so kind > > and share the raw phase data of an super-5065 against a stable reference > > with me? The longer the data trace, the better. > > > > Thanks in advance! > > > > Attila Kinali > > > > -- > > It is upon moral qualities that a society is ultimately founded. All > > the prosperity and technological sophistication in the world is of no > > use without that foundation. > > -- Miss Matheson, The Diamond Age, Neil Stephenson > > ___ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > ___ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Question about frequency counter testing
Hi, Magnus! Sorry for the late answer, I injured my left eye last Monday, so had very limited abilities to use computer. From: "Magnus Danielson" As long as the sums C and D becomes correct, your path to it can be whatever. Yes. It produces the same sums. Yes please do, then I can double check it. I have write a note and attached it. The described modifications to the original method were successfully tested on my experimental HW. Yeah, now you can move your harware focus on considering interpolation techniques beyond the processing power of least-square estimation, which integrate noise way down. If you are talking about adding traditional HW interpolation of the trigger events I have no plans to do it. It is not possible to do it keeping 2.5ns base counter resolution (there is no way to output 400MHz clock signal out of the chip) and I do not want to add extra complexity to the HW of this project. But, the HW I use can simultaneously sample up to 10 timestamps. So, I can push the one shoot resolution down to 250ps using several delay lines (theoretically). I do not think that going down to 250ps has much sense (also I have another plans for that additional HW), but 2x or 4x one shot resolution improvement (down to 1.25ns or 625ps) is relatively simple to implement in HW and should be a good idea to try. I will probably throw out the power hungry and expensive SDRAM chip or use much smaller one :). Yeah, it would only be if you build multi-tau PDEV plots that you would need much memory, other than that it is just buffer memory to buffer before it goes to off-board processing, at which time you would need to convey the C, D, N and tau0 values. Yes, I want to produce multi-tau PDEV plots :). They can be computed with small memory footprint, but it will be non overlapped PDEVs, so the confidence level at large taus will be poor (with the practical durations of the measurements). I have a working code that realizes such algorithm. It uses only 272bytes of memory for each decade (1-2-5 values). I need to think how to do the overlapping PDEV calculations with minimal memory/processing power requirements (I am aware that decimation routines should not use the overlapped calculations). BTW, are there any "optimal overlapping"? Or I should just use as much data as I can process? Please report on that progress! Sounds fun! I will drop a note when I will move on the next step. The things are a bit slower now. Thanks! Oleg Efficient C and D sums calculation for least square estimation of phase, frequency and PDEV.pdf Description: Adobe PDF document ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] nuts about position
I would be quite interested in the results of this test from something like a Ublox 6T or 8 unit. Please keep us posted. Dan On 6/5/2018 2:35 PM, time-nuts-requ...@febo.com wrote: The next thing I want to try is a receiver self-survey vs the post processed results... I may be able to kludge up a test that does a self-survey / precision survey / post processed survey and compare the results of the methods on the same data set. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Maintenance day for MSF 60 KHz service in UK
The UK's National Physical Laboratory have just confirmed that the MSF 60 kHz time and frequency signal broadcast from Anthorn Radio Station will be shut down on Thursday 14 June from 10:00 to 14:00 BST (09:00 to 13:00 UTC) for routine maintenance. The maintenance schedule can be seen at: http://www.npl.co.uk/science-technology/time-frequency/products-and-services/time/msf-outages Regards, Peter ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Raw phase data of super-5065
Hi, certainly the environmental effects are significant and it is precisely for this reason that acquisitions have been made simultaneously on two 5065, one modified and the other not. To verify the results the same measures were taken with another pair of 5065, one modified and the other not. This second test was carried out at another site 300Km from the first one. Both tests showed a better and more consistent medium/long term ADEV than the unmodified HP5065A. I want to clarify that these measures have the objective of verifying the medium / long term stability and not the short term stability of the Super version I agree it is improved.. Luciano Da "Bob kb8tq" kb...@n1k.org A "Luciano Paramithiotti" tim...@timeok.it,"Discussion of precise time and frequency measurement" time-nuts@febo.com Cc Data Tue, 5 Jun 2018 10:05:34 -0400 Oggetto Re: [time-nuts] Raw phase data of super-5065 Hi It is pretty well known that without “help” ( beyond the filter stuff on the super) the 5065 has fairly poor temperature stability and somewhat variable response to pressure and humidity. Taking two samples right off the production line likely would have given you different long term data as a result. If you are going to the trouble of watching these devices for a long time, monitor temperature, pressure and humidity. I suspect you will find correlations …. Bob > On Jun 5, 2018, at 5:44 AM, tim...@timeok.it wrote: > > > Hi Attila, > I am doing the long therm stability test on a couple of HP5065, one original A type, the second B or "super" compared with my best long therm stability, a GPSDO HPz3816A. > This test will be 30 days long. It is a second test, with a second couple of HP5065A/B, to verify the long therm stability of both the version. > > Up to now the data available for version B or "super" only concerned the improvement of phase noise. > > From the first results it seems that the HP5065A is more stable within 30days than the modified version with the filter. > It must be considered that the short-term stability of 5065 is better than the GPSDO / TICC up to 10-80k sec then, in this test configuration the valid data will be beyond these values. > The results will be ready within 28 days and I will be happy to share them in order to have everyone's opinion. > Regards, > Luciano > > > Da "time-nuts" time-nuts-boun...@febo.com > A "Discussion of precise time and frequency measurement" time-nuts@febo.com > Cc > Data Mon, 4 Jun 2018 10:11:50 +0200 > Oggetto [time-nuts] Raw phase data of super-5065 > Hoi zäme! > > Would one (preferably multiple) of the owners of a super-5065 be so kind > and share the raw phase data of an super-5065 against a stable reference > with me? The longer the data trace, the better. > > Thanks in advance! > > Attila Kinali > > -- > It is upon moral qualities that a society is ultimately founded. All > the prosperity and technological sophistication in the world is of no > use without that foundation. > -- Miss Matheson, The Diamond Age, Neil Stephenson > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
