Something else occurred to me after I posted. A 0.15 volt glitch could come from capacitive coupling if there was an open in the PPS output of if it was an adjacent pin.
On Sat, 24 Nov 2012 16:52:50 -0800 (PST), Mark Spencer <mspencer12...@yahoo.ca> wrote: >Thanks all for the responses. > >I am routing the signal via 50 ohm coax to the 1Meg ohm input of a 100 Mhz >analog scope using dc coupling. After some fiddling with the trigger settings >I am able to observe a brief pulse every second that appears to be .15 volts >above ground. I'm not inclined to believe that the signal is actually .15 >volts though. I did try terminating the scope end of the coax with a 50 ohm >load and the signal as displayed on the scope didn't change. I recall making >similar measurements in the past and seeing more reasonable results. >I really don't want to blow the inputs on my 5370B's hence my caution here. I >did try connecting the signal to one of my 5335B's and based on the trigger >settings I was able to use to get that counter to trigger I'm inclined to >believe it is 3.3 or 5 volt TTL level but I'm not 100 percent sure. >I'll have to do some more experimenting with my analog with other 1pps signal >sources to gain more confidence in my measurements and or ask Santa for a >digital storage scope (: > >Regards >Mark Spencer _______________________________________________ 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.
