adykes@panix.com (Al Dykes) hath wroth:

>There are antenna builders that claim that plastic that isn't spec'ed
>for RF may not be as "transparent" as we would like.

True. However, we have a very easy test to see how much RF the
plastic will absorb. Shove a sample of the plastic into a microwave
oven. Insert a glass of water to keep from arcing the magnetron. If
the plastic gets hot, melts, or catches fire, it's unsuitable for RF
at 2.4Ghz.

>FWIW.

It's worth quite a bit. PVC tends to get doped with all manner of
disgusting fillers some of which will dissipate RF. For example,
black plastic PVC pipe is mostly graphite, which is the last thing you
would want in the antenna path. However, if you don't want the
antenna inside, just mount it outside. End of problem.

>It wouldn't be hard to test a box that you'd like to use for
>attenuation. netstumbler and other WiFi sniffer software report DB
>signal strength.

Actually, it's VERY hard to do that with those tools. It's very
difficult to do comparative measurements due to the sensitivity of the
antenna test range to reflections, movement, small changes in
position, and even temperature stability of the wireless devices. I
consider myself quite fortunately if I can repeat an antenna test
measurement to within 3dB.

--
Jeff Liebermann jeffl@comix.santa-cruz.ca.us
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558