A colleague of mine had seen this exact same behavior on another 53230A. The problem is a narrow trace right after the CH1 BNC input. http://www.anderswallin.net/2014/11/53230a-counter-input-channel-fix/
There might be some chemical corrosion going on, since the other counter that experienced this problem had definitely not been subjected to overvoltage or other abuse. Or perhaps it's a mechanical issue where the BNC-connector over time bends the PCB+trace. The BNCs don't appear mechanically anchored to the front-panel, they are just soldered to the PCB and stick out through holes in the front panel. We have one of the 100ps models and probably a third 20ps model also - time will tell if these will break in the same way... Agilent/Keysight - are you listening?!? fix it please :) Anders > Hi all, > > > > I have a 53230A that behaves differently on ch1 and ch2. > > > > With ch2 at DC/1Mohm/postive-slope/1V it triggers ok on my PPS signal and > > shows e.g. a pusle-width measurement etc. > > The same signal connected to ch1 fails to trigger. > _______________________________________________ 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.