No idea. That's what's sad. They all blend together. Sent from mobile
> On Feb 16, 2014, at 6:17 PM, "Jimmy D. Burrell" <[email protected]> wrote: > > Bingo! It's working now!! Thanks to everyone on the thread. > > Paul, I have to give chops to Bob on this one, even though my experience is > the same as yours with respect to the preset triggers. Actually, your > comments/question about the "trigger lights flashing" in concert with the > 1PPS signal got me looking/thinking and no, they weren't. BTW, my 0.000001 > number was meant to be Hz but I left off the units. > > Both Bobs (Camp and Albert) were pointing me at the 'input'. So, I drug out > the HP5335A manual and re-read about all 4 trigger levels. Auto-adjustable > mode allows adjusting the trigger according to the amplitude of the input > signal... a sort of percentage trigger mode, i.e. turn the trigger control > clockwise to 3/4 scale and you're triggering at 75% of the signal's amplitude. > > The above trigger changes combined with reconfiguring for 50ohms input signal > did the trick. I'm now seeing readings like 0.999 999 983 +0. > > Thanks again, > > Jim... > N5SPE > > >> On Feb 16, 2014, at 4:07 PM, Bob Camp <[email protected]> wrote: >> >> Hi >> >> If you have a 50/50 duty cycle 1 pps, it’s going to work with a lot of >> settings. With a narrow (say 10us wide) pulse, most of the counters have >> auto trigger issues. If it’s already known to be reading nutty, trigger is a >> good place to start looking. >> >> Bob >> >>> On Feb 16, 2014, at 4:29 PM, Paul <[email protected]> wrote: >>> >>>> On Sun, Feb 16, 2014 at 2:33 PM, Bob Camp <[email protected]> wrote: >>>> >>>> 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. >>> >>> >>> I can't believe I'm disagreeing with Bob Camp but this is not my >>> experience. 99.9% of the time preset trigger works fine and I think you >>> should start with that. AC coupling almost always works and is sometimes >>> required (with the Rb I think). >>> >>> I have a 5335A (w/ opt 010+040) and have measured 1PPS on my PRS-10, Fury, >>> Firefly and random GPS parts. If the trigger light is not flashing at 1 Hz >>> the only thing I've ever had to do is toggle AC coupling or enable 1PPS >>> output on the device (or plug it in). Sometimes increasing the gate time >>> tidies up the display. >>> _______________________________________________ >>> 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. > > _______________________________________________ > 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.
