The Stack Grows

["Thomas Droege" <tdroege2@earthlink.net>]

I now have 4 good cameras in the "spares" stack.  Actually two of then need
to go to TOM3.  Now that I have a good test setup it is pretty easy to
check out a camera.  Just the hart stopping moment when I first turn it on
to see if I have blown the amplifier.  

With the CCD chips, it seems to me that being careful aside, it is how many
trips you "take to the well" that counts.  Sooner or later if you handle
the chips a lot, something happens.  However, once sealed up, the cameras
seem to be pretty safe.  I have lots of protection on the leads.

Perhaps a pile of cameras will inspire a certain person who has drawings to
think a little more about the Mark V.

I now pretty well understand why the TECs go bad.  If you run the TEC with
the inside of the camera wet, then ice forms around the TEC.  This probably
gets in cracks of the material and fractures it.  Thus there is a slow
degradation of the TECs.  No cure, I think, but to tear the camera apart
and change the TEC.  A pain but not so bad that I won't do it for those of
you that may have killed their TECs.  I have been sealing up the TECs with
RTV.  All with this treatment maintain the same current as when new.  You
can also buy them from Melcor sealed.  To test a TEC apply 12 volts from a
power supply.  It should dray at least 1.5 amperes.  Most new ones draw 1.9
or so in my test set up.    

Tom Droege

Tom  Droege Jennifer Malpass
tdroege2@earthlink.net