> Ideally some immunity to outside interference. This device will be on
> my belt along with a radio (usually UHF commercial), a wireless
> receiver (always UHF), and an intercom beltpack.

The reason that ask, is that as others have pointed out, shielding the
enclosure is difficult, and not all that effective.  Tight layout, low
impedances, avoiding diode junctions in low level analog, and ground
flood are very effective.  You may not have enough control for these
to help.  I have achieved immunity levels > 192V/m with a two layer
PCB and no enclosure at all.

That black IC foam is a good RF absorber, put a chunk that just fits
in the enclosure, inside a plastic bag so the "crumbs" don't get
loose.
--=20
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