> The tau range for which ADEV etc are sensibly independent of measurement > system bandwidth should differ significantly when comparing a pair of > hydrogen masers or a pair of low noise OCXOs (OSA8607, FTS1200 etc).
I'm not sure what "significantly" is, but as you suggested, I do see more of a difference at low tau with two ultra low noise references than with two normal OCXO. The effect is zero to a couple of dB. See plots below. > The lower limit for an 8607 or a good FTS1200 is probably in the 1 to > 10s range. > That is around the value of tau for which ADEV vs tau first approximates > a horizontal straight line or reaches a minimum. > > Bruce Right you are. It's 2 seconds for the pair of 8607's and near 10 seconds for a 8607 vs. active H-maser. Compare these: http://www.leapsecond.com/pages/adev-bw/tbolt-tbolt-bw.gif http://www.leapsecond.com/pages/adev-bw/8607-8607-bw.gif http://www.leapsecond.com/pages/adev-bw/8607-hm75-bw.gif I'll add a maser-maser plot if I have it. /tvb _______________________________________________ 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.
