This specific application doesn't warrant a Teflon substrate, I think it is
FR-4.  Let me clarify one thing, It's assumed that the material is cold
flowing, causing ground interruptions (this is an RF Engineer's assumption).
The fact is that, after time in service, the main complaint from the test
guys is electrical problems associated with a degenerated ground.  It could
be associated with moisture entering the housing causing the tin-lead
plating on the ground plane, which is in direct contact to the housing via
screws, to become slightly oxidized.  This is not a hermetically sealed
housing.  In fact, there is a hole in it to allow for a pot adjustment.
Which leads to another question...  are there bulk-mounted pots available,
mounted directly to the housing wall, which would eliminate the hole?

Jim Marsico
Senior Engineer
Production Engineering
EDO Electronics Systems Group
[log in to unmask] <mailto:[log in to unmask]>
631-595-5879


        -----Original Message-----
        From:   Crepeau, Phil [SMTP:[log in to unmask]]
        Sent:   Tuesday, December 09, 2003 4:47 PM
        To:     [log in to unmask]
        Subject:        Re: [TN] GOOD RF GROUND

        hi,

        is the fastener loosening up because the laminate is teflon based
(which is common in rf applications)?

        phil

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