Hi On all these counters, you need to switch to DC input for 1 pps signals. You also need to manualy set the trigger level to something like +1.5V. Next thing to fiddle is the 1 meg / 50 ohm termination. Sometimes it works better with 50 ohms, sometimes not.
Bob On Feb 16, 2014, at 2:03 PM, Jimmy Burrell <[email protected]> wrote: > I've recently purchased an HP 5335A and for the most part, we're getting > along famously. Then I tried to measure my GPS' 1 PPS pulse. I'm not seeing > anything Iike what I'd expect to see, e.g. 0.000001. Doesn't matter what type > of measurement I select (freq, period) the measurements are nowhere near "1". > In fact they are all over the place and changing a lot faster than once per > second. > > My first thought was "not enough signal" present at the input of the counter > causing a low SNR. But my scope says it's better than 2v on p-p. According to > the HP5335A manual, that should make the counter happy. > > I've never tried measuring any freq. this slow so I'm out of my element. > Probably missing something obvious. > > Any of this ringing a bell with anyone? Any clues or suggestions? > > Many thanks, > > Jimmy... > N5SSPE > _______________________________________________ > 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.
