); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] I guess I'm a bit out of date!
:-) Rob -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Björn Gabrielsson Sent: 17 July 2007 14:13 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Cs stability ); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] "Achieved: Acceleration sensitivities better than 2E-12/g" http://www.zyfer.com/briefings/telecom/qz%20low-g%20brfg%20olie%204-04.pdf -- Björn On Tue, July 17, 2007 14:40, Rob Kimberley said: > Another way that has been incorporated successfully to combat g > sensitivity are accelerometers mounted on each of the x, y, Z axes of > the crystal. > Combining this with spring mounts works well. g sensitivities down to > e-10 per g can be achieved. > > Rob K > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > On Behalf Of [EMAIL PROTECTED] > Sent: 17 July 2007 06:14 > To: [email protected] > Subject: Re: [time-nuts] Cs stability > > ); SAEximRunCond expanded to false > Errors-To: > time-nuts-bounces+rk=timing-consultants.com+rk=timing-consultants.com@ > time-nuts-bounces+febo.c > om > > > In a message dated 7/16/2007 12:10:54 Pacific Daylight Time, > [EMAIL PROTECTED] writes: > >>For example tilting the Cs unit by 90 degrees will typically give an >>error > >>of about 1E-09 or so. > >>It would take some time for the control loops to compensate for this > error. > > > > Hi guys, > > I did tilt my 4050 when I first installed the unit, that number is > from my memory. Notice that Magnus is right of course, the Cs will > compensate the tilt, given enough time to do so. I did not mean that > the 1E-09 error will stay permanent of course, as I said in the > follow-on sentence. > > Also the 4050 is not very well temperature compensated compared to > modern units, I was not impressed when I saw the FTS tempco > specifications. A good GPSDO can outperform the 4050. > > I have a military OCXO sample (new product) that is supposed to be > "g-insensitive" and even that one has about E-09 frequency shift per > 90 degrees tilt. > > One of the only ways to get around that is to use three crystals in > series, with the three crystals oriented in the the XYZ axis, so their > errors compensate out. > > Vibration is also a big enemy of crystal oscillators of course. > > bye, > Said > > > > ************************************** Get a sneak peek of the all-new > AOL at http://discover.aol.com/memed/aolcom30tour > _______________________________________________ > 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.
