Hi Bob, Send me the raw data and I'll have a look to confirm or explain your results.
I've seen this in some of my FTS 1050 also; it's always been the fault of the battery charger circuit. /tvb ----- Original Message ----- From: "Robert Darby" <[email protected]> To: <[email protected]> Sent: Sunday, July 07, 2013 12:27 PM Subject: [time-nuts] Question about effect of sample interval on ADEV > This is a question that has probably been addressed on the list and in > various texts but I've been unable to find an answer that I can fathom > so here's a request for some info about the behavior of TimeLab (and > probably all other similar programs). > > I have been trying to find the source of some periodic noise that > appears when using a 5370B to measure an FTS 1050B against a 5065B. The > noise manifests itself varying from 12s to 20s in a repetitive fashion. > I asked C. Dawson about this and one of his suggestions was to try a > longer sampling period. Down the rabbit hole I went! > > I ran four trials in succession at sample intervals of .07s, .25s, .5s, > and 1s. The result is as if the adev ,modified, and Hadamard curves > have been slid down and to the right along the noise floor of the 5370. > > My assumption, apparently incorrect, was that the software would take > the sampling interval into account so that I would get essentially the > same plot. When I edit a plot changing the sample interval, the trace > remains essentially unchanged and this seems inconsistent with the > results noted above. Can anyone explain in relatively simple terms what > I'm missing? > > Thanks, > Bob Darby _______________________________________________ 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.
