Zyfer have(had?) some papers on g-compensated oscillators by Fruehof. -- Björn
<div>-------- Originalmeddelande --------</div><div>Från: D W <[email protected]> </div><div>Datum:2015-05-12 17:49 (GMT+01:00) </div><div>Till: Discussion of precise time and frequency measurement <[email protected]> </div><div>Rubrik: Re: [time-nuts] 53132A Polish UHS Time Base Option Interesting Ovservation </div><div> </div> And this is where one question leads to another. For an oscillator that is going to be used at very high velocities and accelerations, like in a missile, would it be calibrated somehow under the target G force? Or would you just compensate some other way? Or just not worry about it? Dan > On May 12, 2015, at 6:51 AM, Bob Camp <[email protected]> wrote: > > Hi > > All OCXO’s are sensitive to acceleration. Gravity is one form of > acceleration. A > sensitivity in the 0.5 to 2 ppb / G is not uncommon. > > Bob > >> On May 11, 2015, at 9:24 PM, J. L. Trantham <[email protected]> wrote: >> >> I recently obtained a 53132A and added the HP Opt 010 High Stability Time >> Base option with a 10811 variant OCXO. >> >> >> >> I left it on for over a week and it, ultimately, seemed to slow down in its >> drift, with the displayed frequency, as it 'read' my GPSDO, slowly >> decreasing, suggesting that the Time Base was, slowly, increasing in >> frequency. >> >> >> >> I then removed the HP option and installed a Polish UHS Time Base option >> with a Morion DOCXO. After about 72 hours, it seemed to stabilize. I then >> 'calibrated' the 53132A by connecting my GPSDO to Channel 1. The displayed >> frequency was +/- 1 to 2 mHz of 10.000 000 000 MHz for the past week or so, >> with no drift noticeable. >> >> >> >> I had 'calibrated' the 53132A with it sitting at about +30 degrees, propped >> up on its 'handle' in a 'vertical' position. I then had occasion to move >> the 'handle' under the unit whereby the unit was 'flat', at which point the >> displayed frequency dropped to 9.999 999 997 MHz, +/- 1 to 2 mHz. The >> displayed frequency was the same this evening when I came home. When I >> again 'elevated' the unit by moving the handle to its more 'vertical' >> position, the displayed frequency moved to 10.000 000 000 MHz +/- 1 to 2 >> mHz. >> >> >> >> I'm not sure what this means. >> >> >> >> It is a 'repeatable' observation. It displayed the lower frequency all day >> and when I 'elevated' the 53132A this evening, the frequency again went to >> 10.000 000 000 Mhz. Is this a 'gravity' effect? Is this an issue with the >> DOCXO? Is this an issue with the 53132A? If I am correct in my >> calculations, the displayed frequency is +/- 1 to 2 parts in 10E-10 of 10 >> MHz, assuming my GPSDO is accurate and stable. Otherwise, the GPSDO and >> 53132A 'drift' is exactly the same. >> >> >> >> I would appreciate anyone's thoughts regarding this analysis and observation >> and how to go about 'quantifying' it in a more scientific method, assuming >> it's worth pursuing. >> >> >> >> Thanks in advance. >> >> >> >> Joe >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
