I've found with my HP5370B's they perform best over a fairly narrow range of input signal levels. (1 to 2 volts If I recall correctly ?) Some experiments might be in order for yours. Virtually all my testing was done with 5 or 10 MHz sine waves so this may or may not be helpful in your case. I found in line attenuators and an oscilloscope to be helpful in making measurements using my HP5370B's.
I've never done a full alignment of mine so this behaviour may not be typical. All the best Mark S Sent from my iPhone >> On Feb 24, 2016, at 1:36 AM, Bruce Griffiths <bruce.griffi...@xtra.co.nz> >> wrote: >> >> On Wednesday, February 24, 2016 12:55:42 AM Enrico Bellotti wrote: >> Hello to all, >> >> first of all, thank you for the great and useful work that the time-nuts >> have done over the years. >> >> I have finally been able to gather all my counters (HP5335A, HP51131A, >> HP5370A, HP5370B #1, HP5370B #2) and try to do some "simple" measurements. >> >> I have started testing and comparing the instruments I have available using >> the approach that was discussed a while ago on the list and also outlined >> by John Ackermann (http://www.febo.com/pages/hp5370b/). Specifically, the >> Adev for a time interval measurement on a (90ft of) RG58A/U cable. >> >> I have attached a PDF file with the results and some additional details of >> the test setup. >> >> From what I have understood the Adev at one second is related to the >> counter resolution. The results I have obtained seem to be reasonable >> except for HP5370B #2. This instrument seems to be marginal at best. Does >> anybody know if the measured value for HP5370B #2 is a symptom of a >> multifunction or simple need for calibration? >> >> Thank you for any comments/suggestions/corrections you may have. >> >> Best. >> Enrico > Try repeating the test with a low noise external reference/If that doesn't > improve the results try realigning the filters etc in the 10-200MHz > multiplier. > > Bruce > _______________________________________________ > 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.