Jerry, My guess is that the amplitude of the reference signal may be on the ragged edge of what the counters require- either just barely adequate, or much too "hot" and being distorted. Also, check to see if the source and load impedances are matched. I once corrected a similar problem by inserting a 2 dB attenuator in line with the reference signal. And check to be sure that the reference signal is not riding on a DC level.
73, Eric Lemmon WB6FLY -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Jerry Mulchin Sent: Wednesday, March 21, 2012 5:06 PM To: [email protected] Subject: [time-nuts] Frequency Counter Errors I have a question for the collective group. I have a HP 5372A and a HP 5328A frequency counters. Both counters use the same PRS-10 Rubidium frequency standard driving a 6 channel reference distribution amplifier to each counters reference input port. The problem is this; When I measure the same frequency on both counters, (done one at a time) the frequency is generally off by about 300 Hz or so between the counters. Now I would expect an error of +/- 1 digit, but 300Hz seems a bit strange to me. I can not find the problem and the difference exists even if I use the internal timebases of each counter, give or take the timebase errors. The frequency is always at least >200 to 300Hz off between the two counters and I don't know which one to believe. You know the "man with 2 clocks" problem. Anyone have any idea what may be causing this? Thanks Jerry _______________________________________________ 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. _______________________________________________ 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.
