HV Testing (was:Re: Newbie's got a dead 386) - test-drb@ccmp.vtda.org

19 Nov 1998

...
   Another one -
How do you test supplies and various heater controls that have
  to float at 8Kv?  I.E.: their common point is at
8Kv.  Especially when they
  are intermittent and you can't tell without
the HT on exactly when it is
 acting up.  VERY carefully float your meter at kV and be very sure you don't
  touch the meter and don't do like I did and
get to near the leads while
 operating the instrument while waiting for the intermittent to act up. An
  8Kv @ 5ma with 1ppm stability supply burns holes
on the way in and out. In
  the arm and out the finger. 
I'd recommend:

1.  Get one of those rubber holsters for the meter and allow only the
holster to touch the equipment.

2.  Make some test leads out of EHT wire.  The sort of stuff that's used
for the anodes of CRTs and things.  Maplin used to sell it (haven't checked
recently), rated at 25 kV, and I'm sure other suppliers do too.

3.  Failing no. 2, car engine HT leads may be useable, but most of them are
quite rsistive, so check the calibration! 

I agree but that adds weight and bulk to an already overstuffed and heavy
tool / parts case that I will not check through airline baggage.  It is
something that I have to do only a couple times a year so I realize I am
taking chances and after the bite of 8Kv I tend to be even more careful.  I
have some 40KV rated test lead which would work but it is bulky for use on
the road.
Keep in mind that I used to be in 2 to 4 cities a week.  99% of the time
with airline flights between each city.  Weight and bulk is a BIG
consideration then.

The most important thing I was trying to point out with the first item in
that post is NEVER assume the meter is correct.  It will bite you.
Dan