Hi Dump it to a csv file and do it in Excel would be one way. You want to be able to control the process a bit so that would give you the ability to tweak the measurement.
Bob > On May 3, 2017, at 11:01 AM, Bob Stewart <b...@evoria.net> wrote: > > Hi Bob, > > What I should have asked is this: "how do I get that from a Timelab dataset?" > > Bob > > > From: Bob kb8tq <kb...@n1k.org> > To: Bob Stewart <b...@evoria.net>; Discussion of precise time and frequency > measurement <time-nuts@febo.com> > Cc: Tom Van Baak <t...@leapsecond.com> > Sent: Wednesday, May 3, 2017 7:20 AM > Subject: Re: [time-nuts] Three-cornered hat on timelab? > > Hi > > RMS: > > https://en.wikipedia.org/wiki/Root_mean_square > <https://en.wikipedia.org/wiki/Root_mean_square> > > When we talk about things like “6 sigma” in QA, the sigma is the RMS. > > Bob > >> On May 3, 2017, at 1:44 AM, Bob Stewart <b...@evoria.net >> <mailto:b...@evoria.net>> wrote: >> >> Hi Tom, >> Could you clarify the term RMS? Is there some sort of calculation I need to >> do on the raw data to get the RMS value? >> I'm going to begin by doing a fresh 8 hour test of GPSDO Unit 1 vs GPSDO >> Unit 2, with the same conditions as the tests involving the PRS. IOW, the >> 5370 is being clocked by GPSDO Unit 2, and the trigger for the EXT input to >> the 5370 is from GPSDO Unit 2. START is from GSPDO Unit 1 and STOP is from >> GPSDO Unit 2. The ones I have on hand show about 4E-11 at 1s tau. >> >> After that, I'll run an 8 hour test of raw 1PPS from a LEA-6T against the >> PRS. Since I don't really trust the PRS, I'll use GPSDO Unit 2 to clock the >> 5370. If you really don't want the GSPDO to clock the 5370, I'll run the >> same test using the internal 10811 as the clock, to compare the difference. >> >> I also ran into an old test of the 5370 where START (10MHz) was fed by a >> GPSDO and STOP (10MHz) was fed by the same GPSDO but with (I think) a 20 ft >> cable from START to STOP. I'll probably want to rerun that, as well, but it >> was an almost straight line from 2E-11 at 1s tau in that dataset. Still, >> that test will verify that the 5370 hasn't degraded. Bob >> >> From: Tom Van Baak <t...@leapsecond.com <mailto:t...@leapsecond.com>> >> To: Discussion of precise time and frequency measurement <time-nuts@febo.com >> <mailto:time-nuts@febo.com>> >> Sent: Wednesday, May 3, 2017 12:02 AM >> Subject: Re: [time-nuts] Three-cornered hat on timelab? >> >> Hi BobS, >> >>> I've also made the timelab file (compressed by 7z) available here: >>> http://evoria.net/AE6RV/Timelab/GFSvsCS.4.22.17.7z >>> <http://evoria.net/AE6RV/Timelab/GFSvsCS.4.22.17.7z> >> >> Thanks for sharing that. To follow-up on recent emails... >> >> When you start to push the limits of your own test equipment it's good to >> employ tricks such as 3-corner hat in order to get a few dB better >> measurement. But there's a limit to that. And you probably don't want me to >> suggest that you run 3 GPSDO, 3 counters and 3 cesiums all simultaneously. >> >> I've attached two plots showing 4+ days of your GPSDO data and 4+ days of a >> TBolt (factory defaults, *untuned*) >> >> bob-gpsdo-3.gif -- Notice how much your GPSDO (blue trace) wanders all over >> the place. >> >> bob-gpsdo-5.gif -- ADEV comparison. See below for comments. >> >> 1) >> When I look at the ADEV for your data set it's pretty clear that the >> limiting factor on the left (short tau) is the resolution of your 5370A >> counter. That's why the TBolt looks better. Don't worry about that. >> >> 2) >> In the middle of the ADEV plot it would appear that both your 5370A counter >> and your PRS-45A cesium reference are sufficiently good to properly measure >> your GPSDO. That's good. The TBolt looks bad in the middle but that's simply >> because it was using a way-too-short default time constant. With proper >> tuning the red trace would be mostly flat out to 1000 seconds. >> >> 3) >> From the look of the phase plot and the ADEV plot it almost seems to me like >> your PRS-45A is the limiting factor on the right (long tau). If so, it would >> explain the lack of diurnal and sidereal effects in your data. If you look >> at: >> http://leapsecond.com/pages/tbolt-8d/sigma1.gif >> <http://leapsecond.com/pages/tbolt-8d/sigma1.gif> from >> http://www.leapsecond.com/pages/tbolt-8d/ >> <http://www.leapsecond.com/pages/tbolt-8d/> >> you'll note the sidereal "blip" is below 4e-14. Your ADEV doesn't get near >> that level. >> >> >> I say this because a rule-of-thumb is that a good M12+T timing receiver >> should get you down to 3 ns per day RMS. And a good ublox-6T can get you to >> 3 or 2 ns per day RMS. Your data shows something more like 5 ns -- which for >> a GPSDO is worse than no GPSDO at all. So something's wrong. What set of >> experiments can you perform to locate the problem? Or, what experiments can >> you perform that don't require buying expensive gear? >> >> My first suggestion is for you run a standalone GPS timing receiver like a >> M12+T or ublox-6. Put all your GPSDO away. Just use that OEM board, and your >> TIC, and your PRS-45A. Collect sawtooth data too. You should get down to 2 >> or 3 ns RMS. >> >> /tvb >> >> ----- Original Message ----- >> From: "Bob Stewart" <b...@evoria.net <mailto:b...@evoria.net>> >> To: "Discussion of Precise Time and Frequency Measurement" >> <time-nuts@febo.com <mailto:time-nuts@febo.com>>; "Magnus Danielson" >> <mag...@rubidium.se <mailto:mag...@rubidium.se>> >> Sent: Thursday, April 27, 2017 9:48 AM >> Subject: Re: [time-nuts] Three-cornered hat on timelab? >> >> >> Hi Magnus, >> Try as I might, the weather and the local power company had other ideas >> about my long term capture. I'm running everything but the 5370 from a UPS. >> I guess I'm going to have to get batteries for my other UPS and run the 5370 >> from that. A one second power loss was all it took to stop the test. >> >> Anyway, I did manage to get 376,238 points of data. The data is captured on >> a 5370A. The external clock input and the STOP channel are fed by the 10MHz >> from my PRS-45A. The START channel is fed by the 10MHz from one of my >> GPSDOs. The EXT channel is fed by the 1PPS from another of my GPSDO units. >> "EXT ARM" is enabled. So, essentially, at every 1PPS pulse, the phase >> difference between the two 10MHz feeds is captured. >> >> I've attached a screenshot of the phase plot which can also be found >> here:http://evoria.net/AE6RV/Timelab/Screenshot.png >> <http://evoria.net/AE6RV/Timelab/Screenshot.png> >> I've also made the timelab file (compressed by 7z) available here: >> http://evoria.net/AE6RV/Timelab/GFSvsCS.4.22.17.7z >> <http://evoria.net/AE6RV/Timelab/GFSvsCS.4.22.17.7z> >> >> So, back to my question: Where are the large ionospheric phase moves? This >> question has been causing me doubt since I started on this project. Or don't >> I still have enough data collected for this to happen? >> >> Bob >> >> ----------------------------------------------------------------- >> AE6RV.com >> >> GFS GPSDO list: >> groups.yahoo.com/neo/groups/GFS-GPSDOs/info >> >> From: Magnus Danielson <mag...@rubidium.dyndns.org> >> To: Bob Stewart <b...@evoria.net>; Discussion of precise time and frequency >> measurement <time-nuts@febo.com> >> Cc: mag...@rubidium.se >> Sent: Tuesday, April 18, 2017 1:09 AM >> Subject: Re: [time-nuts] Three-cornered hat on timelab? >> >> Hi Bob, >> >> That is a good solution indeed. Good luck with that measurement run! >> >> One of the fun stuff with Timelab is that you can walk by and check the >> developments. I've found that very useful for long measurements (as in >> hours and days). >> >> I prepared a cesium for one vendor, and initially they did not care so >> much, but then they saw more deviations between the receivers, so they >> wanted to sort it out, but discovered that they could not cancel out the >> common mode of GPS signals (and its shifts), so then firing up that >> cesium was the right thing. I remember writing support emails while >> waiting for the airplane in Madrid airport, happy that they was doing a >> first run for the right measurement reason. :) >> >> Cheers, >> Magnus >> >> On 04/18/2017 04:25 AM, Bob Stewart wrote: >>> Hi Magnus, >>> Today I started a long run against my PRS-45A. Maybe this time I won't have >>> a power outage. I'll see what it tells me in a few days. >>> Bob_______________________________________________ >> 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.
