Nick, I have gotten this process down to a 'science', I think. The best
way i have found to vet these things, because they are just plain flaky,
is to set up a mass burn in station. By that I mean, set up a station
where you can burn in several, I usually do 5 or 6, and let them burn in
for at least a 3 -4 days each. I found that after that time period , if
they're OK and exhibiting no
noticeable 'wobbling', you have a
winner. See attached . I also make sure to make the raised dot side hot (
although I'm not sure that makes a whole lot of difference). There is a
raised dot in the glass envelope on the base of these things that I
think indicates the Cathode side, although there seems to be uncertainty
about that too. Anyway, using this method I have ended up with several
INS-1's that have lasted over 10 years and no wobbling. As some of you
may know, I am sort of obsessed with using these things as center eyes
in my clock designs. Can send pics of how I set this up. Right now for some reason I am unable to upload pics to this post