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Re: PCSAT2 ready for flight



>Very interested also in the PCSAT 2 outgassing aspects you 
>mention......  but can you confirm that you coated 
>these latest circuit boards with conformal coating - including 
>all  the various plastic parts?  

Yes, the boards were baked for 24 hours at I think 80 C and
then conformal coated.  BUT we learned that conformal
coating has nothing to do with outgassing.  The only thing
conformal coating does is to protect the circuits from floating
bits of aluminum shavings in zeroG that could land just about
anywhere and short out all kinds of things.

We didnt do the coating ourselves (its easy enough) but 
that wasnt our job in this project.  So I know nothing about it
other than it is kinda rubbery and you can easily pull it off
if you can get a-hold of it.  Its like a thin very flexible rubber
coating.  Its not like the HARD plastic stuff they use on 
Earth that also helps with mositure blockage etc...

Maybe someone else on AMSAT-BB knows the name of
the stuff.  ALso, it only detuned our open-air RF coils
slightly so that we noticed about a 10% loss in power.
We decided that was OK and did not try to re-tweak...

>I purchased some (new) water based material when I was 
>in UK last year  (Humiseal 1H2O) but they still haven't any 
>outgassing figures for it. 

One thing we did was take a spare (junk transmitter) that
had other problems and had it coated first so we could
see how it changed.  Nothing other than the 10% above.
AND we found that we could ask for anything to be
masked and not coated.  They had little stickers that
they would stick onto anything we didnt want coated.
We put those over the top of the coil cans.

We let them coat the variable caps because this stuff
is so easy to remove, just an exacto knife to cause a
little incision and you could pull the stuff off the top of
the cap in once piece...  It coats, but does not "stick"
to stuff much more than "post-it"notes do...

Ill see if I can find out what it is...
Bob
WB4APR
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