tempest PCB only some vectors shaky

Howdy -

I'm trying to figure out why some, but not all, of the lines are shaky on
my Tempest PCB. I set my oscilloscope to XY-mode with 1 sec persist and
captured a screenshot. I'm not sure if it's allowed to send an attachment
to the list, so here's a link:

https://picasaweb.google.com/lh/photo/CYke3MLZ4e94Cf5vb2UUPkuaTiHWm12LLNxmPUaffgU?feat=directlink

This is one corner of the diagonal line + alphabet self-test. Notice the
blue line is solid but the red line is quite noisy. Predictably on the XY
monitor the blue line is rock solid but the red line is shaky.

I've already replaced the TL082s just in case. I don't suspect the DACs
since the lines are both in the same corner and I'm not seeing stair-step
error. Does anybody else have a theory of what makes those two lines
different, and why one might be rock solid and the other one shaky?

-joey

---------------------------------------------------------------------------
** Unsubscribe, subscribe, or view the archives at http://www.vectorlist.org
** Please direct other questions, comments, or problems to chris@westnet.com
Received on Mon Jun 4 19:21:40 2012