Well, let's see: usually the Allan deviation is computed by collecting phase (time error) samples. You have to select time interval in TimeLab and on the PM6680 TIME A-B. If you want to use frequency samples (this is strange for me, never used frequency samples) then you must select frequency in TimeLab and FREQ A on the PM6680. Selecting TIME A-B requires that you use both the A and B inputs (start and stop) to time your signals but since you are trying to measure the TBolt with itself you must delay the signal going to A before it reaches B. Use a long coaxial cable as a delay line (50 meters should work). Measuring a signal with a delayed replica of itself can be useful to see how good is the counter.
On Tue, Jul 3, 2012 at 6:26 PM, cfo <xne...@luna.dyndns.dk> wrote: > On Tue, 03 Jul 2012 18:11:26 +0200, Azelio Boriani wrote: > > > When you start TimeLab, which mode does the PM6680 show? FREQ A or TIME > > A-B? > > > It shows Data Type = time interval , i could also select frequency in the > drop down box (This is the latest TimeLab - NonBeta). > > Now have i goofed ? > Is time interval A->B inputs (blush) > > CFO > > > > > _______________________________________________ > 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. > _______________________________________________ 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.