In a message dated 4/10/2007 14:48:34 Pacific Daylight Time, [EMAIL PROTECTED] writes:
with a 53132A against a good atomic house standard. You'll see a large phase offset (many microseconds), a frequency offset (about +3e-12 or -3e-13). No, I didn't remove frequency drift (if any) from the data before I plotted it. Hi Tom, how do you best compare an atomic standard against an OCXO on the 53132A? I did it with the 1PPS inputs (that works, but gives only one sample point per second). Inputting 10MHz and doing T1 to T2 intervall measurements also works somewhat, except using the internal gate delay is not perfect, I get aliasing (there is some 100ns offset sometimes - which is random). It works best (no aliasing) when I let the counter free-run without any gate-delay, but then I do not know the sample Tau of my data. That's partially because I am using the serial port output at 19200 Baud, and I think the counter is spitting data at me as fast as it can (limited by the RS232 port). Seems its about 15-20 measurements per second free running. I am thinking that maybe I should provide a 100ms external gate input etc, at least that way I will know for sure that my Tau is 0.1s and I get 10x more data than simply comparing the 1PPS outputs. Lastly, I have the High Stability time base, but have still been using an external Cs reference to feed 10MHz into the counter. I wonder if the internal time base is better (probably less short term ADEV than the Cs) for these short time intervall measurements. Any hints are appreciated, Thanks, Said ************************************** See what's free at http://www.aol.com. _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
