); SAEximRunCond expanded to false Errors-To: [EMAIL PROTECTED] From: [EMAIL PROTECTED] Subject: Re: [time-nuts] Cs stability Date: Tue, 17 Jul 2007 01:13:58 EDT Message-ID: <[EMAIL PROTECTED]>
> Hi guys, Hi Said, > 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. Ah. The it was certainly a crystal detuning which took some time to overcome by a sluggish control-loop. On the other hand, few Cesium beams should be required to handle quick 90 degrees tilts during operation. They should sit firmly in the rack. Touring cesiums is a different buissness, but they should rarely have to handle quick tilts during operation too. > 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. Several developments have occured since 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. ... and you have not put a GPS diciplining on it yeat??? > 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. As I recall it, both gravity force and magnetic fields will contribute to crystal detuning. > Vibration is also a big enemy of crystal oscillators of course. As always. Cheers, Magnus _______________________________________________ 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.
