John Ackermann N8UR wrote: > John Ackermann N8UR said the following on 12/01/2007 04:07 PM: > > >> I use the 100 second average for two reasons: first, it results in a >> somewhat better resolution than the 2ns native of the HP-5334A TIC, >> which may or may not be meaningful in the ADEV calculation given the PPS >> noise. Second, it smooths the peak-to-peak noise, particularly from the >> GPS, and makes for smoother phase plots, particularly when one of the >> sources is GPS (I realize that 100 seconds isn't long enough to >> integrated out the GPS noise; when I do my long-term plots, I further >> reduce the data to tau = 1 hour and even tau = 1 day which is more >> meaningful). >> > > By the way -- another reason I linger on each PPS pair for 100 seconds > is to slow down the wear rate on the relays in the 59503A switch! > They're good for millions of cycles, but why switch every 1 or 10 > seconds when there isn't any measurement gain from doing so? And, if > I'm going to sit in one place for 100 seconds, I may as well take 100 > readings instead of just 1. :-) > > John > > John
Deadtime issues only arise if one combines successive 100 second measurements separated by (N-1)x100 seconds. Finite relay lifetime is an issue if one is logging for months or years on end. Bruce _______________________________________________ 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.
