gareth wrote:
I believe that there is a test for the efficacy of materials at RF by
putting
a small quantity in a microwave oven, together with a mug of water to
see if they get hot (and are therefore unusable)

Anybody tried this and can report back?

Yes.

It will tell you whether or not the material aborbs energy at about 3 GHz.

If it does, there is a very good chance, but not guarantied, that it will
absorb energy at low frequencies.

A low frequency test with equipment generally available to a ham would
be something like a dip meter and see if the material has an effect
on a coil.

And conversly, no effect at low frequencies does not guarantee no effect
at high frequencies.


(I shall cease cross-posting my homebrew posts also to uk.radio.amateur
because that only brings forth the Mongolian Hordes of children behind
the fence of the kindergarten school who wish to become the centre of
attention and make fools of themselves by shouting off personal abuse.

It is a sad reflection on the state of amateur radio in Brit, but there we
go)

Ending every post with a paragraph like this one is like waving a cape in
front of a bull and wondering why the bull charged.


--
Jim Pennino