[time-nuts] Question re 1pps output on the Z3805A

[David]

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
<mspencer12345 at 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