Hi Tom:On 8 May I had been plotting for a number of days and saw a similar line indicating a frequency offset of 472E-15. So on that date I dialed in an offset of +472E-15.
For a couple of days the frequency didn't change more than +/- 10ns.Then on the third day it started the plot you see AND the new slope is about the same as the old slope i.e. 470E-15. BUT, the frequency offset display reads 472 (E-15 units). Do you see my dilemma?
See Attached display photo. Have Fun, Brooke Clarke http://www.prc68.com/P/Prod.html Products I make and sell http://www.prc68.com/Alpha.shtml All my web pages listed based on html name http://www.PRC68.com http://www.precisionclock.com http://www.prc68.com/I/WebCam2.shtml 24/7 Sky-Weather-Astronomy Web Cam Tom Van Baak wrote:
If you look at the plot I attached as a .pdf you can see that the current slope looks like a nice straight line covering almost 4 days so temperature is not a factor. The only factor I can think of is magnetic field. I guess the next step is to rotate the box 90 degrees and see what happens unless there's some other suggestions.Since you are plotting phase (not frequency) the nice straight line you see simply means you have a frequency offset. This is normal and expected with any standard compared to GPS. What may be temperature effects are the little wiggles above and below the line. You can almost see they form a diurnal pattern. If you subtract the frequency offset before you plot, you'll get phase residuals, which will reveal patterns in greater detail. There are Excel functions that will help you fit lines to the data and remove trends, etc. Email me your XLS file offline and I'll show you. /tvb _______________________________________________ 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.
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