Hi Having run tens of thousands of standards on these sorts of tests … the one that is more temperature / pressure sensitive *will* show up as having worse long term stability.
1) If your environment swings +/- 1C over 48 hours. 2) If unit A is 1 ppb 0 to 50 ( = 20 ppt / C) 3) If unit B is -0.2 ppb 0 to 50C ( = -4 ppt / C) 4) Both will have degraded stability on a plot that shows 2 days of data 5) Unit A is “at spec” for the 5065, unit B is better than the rated performance. After many decades .. who knows what the spec is …. Unit B will show up as 5X better on a long term test than unit A with both in *exactly* the same environment. Holding 1 C over 2 days is doing well even for some ( but not all ) environmental chambers. I’m by no means claiming that this *is* the only source of the difference. The point is that the temperature stability rating on these devices is not very good. They are quite temperature sensitive. There are a lot of OCXO’s out there that do much better on stability than a 5065 temperature wise. Bob > On Jun 8, 2018, at 10:07 AM, tim...@timeok.it wrote: > > Hi, > > This test requires that the two Rubidiun be installed in the same cabinet so > they are subject to the same temperature and atmospheric pressure. > Acquisitions were made simultaneously.To confirm the data collected, the same > test was repeated in another site with two different HP5065, one modified in > B or "supe" and the other unmodified. > > The results were very similar, that is, both the Super version has a worse > lmedium term Adev than the unmodified version. > All this suggests that the modification with the addition of the 780nm filter > worsens the medium term stability of the HP5065. > > Therefore I would tend to exclude that the results obtained depend on the > different sensitiveness towards atmospheric pressure or to the variations of > the environmental temperature. > > It would be interesting that for further confirmation of what I have deduced > other people could carry out the same tests in the medium and long term Adev > stability. > > Luciano > www.timeok.it > > > > > > 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 Fri, 8 Jun 2018 09:02:34 -0400 > Oggetto Re: [time-nuts] Raw phase data of super-5065 > > Hi > > Ok, so this question should not come as a great surprise: Does one of the > 5065’s have about 3X the temperature > sensitivity of the other? ( or pressure or humidity ). > > Bob > > > > > On Jun 8, 2018, at 8:05 AM, tim...@timeok.it wrote: > > > > > > Here a ten days simultaneously run of the A and B version compared with my > > HP Z3816A GPSDO. > > Luciano > > > > > > Da "time-nuts" time-nuts-boun...@febo.com > > A kb...@n1k.org > > Cc "time-nuts" time-nuts@febo.com > > Data Wed, 6 Jun 2018 08:18:27 +0200 > > Oggetto 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. > > <HP5065A-B vs Z3816A.xps>_______________________________________________ > > 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.
