Hi > On Dec 9, 2014, at 6:57 PM, Richard (Rick) Karlquist <rich...@karlquist.com> > wrote: > > > > On 12/9/2014 3:02 PM, Bob Camp wrote: > Here's an overnight ADEV plot against the new Cs of where we are in the > project. Red is ADEV. Green is the TIC. Blue is the output of the GPSDO to > Channel A and the Cs to Channel B of my 5335A measuring TI, using the 1PPS > from my GPSDO to trigger the external gate. I see that the Cs phase has > drifted down slightly vs my GPSDOe. I wonder if this is an indication of a > calibration problem with the Cs or some subtle issue on my board? >> >> Looks perfectly normal to me. Your Cs is sensitive to magnetic field. Have >> you “zeroed” it out? No of course not, nobody does. (almost nobody …). >> >> Bob > > This reminds me of the great CBT demagnetizer debate at HP. > Even Len Cutler didn't think this was necessary, at least > in the 5071, and possibly the 5061. When Len says something > is overkill, you can be sure of it. Anyway, we still had > to support a CBT demagnetizer for customers who wanted it. > The customer (with money to spend) is always right. The > 5071 measures the C-field with a Zeeman line measurement > and adjusts it if necessary.
… and it seems to do *something* roughly every 24 hours …. That might include “react to the heating turning off in the building ..”. Bob > > Rick Karlquist N6RK > _______________________________________________ > 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.
