Hi Ok, so the data is already decimated and it does show a 20 hour period.
The way I'm reading things - the pps's start out at zero offset on the left side (yellow line at about sample 350). They still are at roughly zero offset on the right side (at about sample 17045). Total peak to peak in the yellow line is 0.5 ns. Total peak to peak in the red line is 1.4 ns. One ns over 20 hours would be 1.4x10^-14. So back to the original question - was drift in the pps removed before the graph was done? Bob -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Fabio Eboli Sent: Wednesday, December 12, 2012 3:42 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] MT3339 PA6H and Racal Dana GPIB, update Bob Camp <[email protected]> ha scritto: > Hi > > 20 hours should be 20*60*60 = 72000 samples. The graphs appear to show about > 17,000 samples. Hello Bob, unfortunately I'm not logging all the pps samples, I'm picking one sample every about 4 pulses, because I'm triggering the counter and waiting 4s before reading the result. So these are not consecutive pps periods. See my previous message of 11-Dec 23:36. Here I have two main problems I will try to solve for now: - I have to understand how to sync the logging script to the counter, so I can read all the values. - The counter cannot read every pps in period mode, but one every two, so I will try to use the start-stop method, since this FE5680 frequency is fortunately very close to the mark. > > If the results do cover a 20 hour period and do not have drift removed, > that's a good FE5680. 1.4x10^-14 is an amazing number for one of those. > > Bob Sorry, here I don't follow you, maybe my graph is misleading, or I'm not understanding, but I see that the FE5680 frequency seem wrong by 3x10^-10 and goes up and down by 3 to 4x10^-10, it's not thermoregulated but simply mounted on an aluminium plate, into a room not thermoregulated. Fabio ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program. _______________________________________________ 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.
