Jim Higgins wrote:
On Wed, 27 Apr 2005 17:23:33 -0700, in
, "John Smith"
wrote:

Thanks Cecil/Atec... I have expanded my list of antenna materials! And, the
microwave will be my authority...

You might want to remember to put about a cup of water - or half
a cup at least - into the microwave along with whatever you test
to avoid possible problems with pumping power into an unloaded
cavity. Every microwave instruction manual I've ever seen warns
about running them empty, and a lot of unaffected material like
PVC tubing is the same as empty.

Because the inside of the oven tends to get warm and steamy, everything
tends to warm up a little. It's best to compare the material you're
testing against samples of known good materials like PTFE, polyethylene
(the insulator from RG214) or a hot-melt glue stick.

The regular translucent hot-melt glue material (amorphous polypropylene)
is also an excellent RF insulator. It's useful for all kinds of antenna
building and weather-sealing.


--
73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek