On Sat, 27 Sep 2008 10:50:34 -0500, - HAL9000 wrote:

Has anyone given thought to converting attic "techshield" insulation
to a HDTV suitable antenna? I have a roof dormer (vertical section)
that faces the desired reception direction.

I am thinking a UHF patch antenna and a VHF patch antenna and then
combining the two - traditionally.

Yes, I've used the stuff for patch antennas at 2.4GHz. It has a very
convenient aluminum foil layer on both sides. It works fairly well
with various foam dielectrics being useful well into the microwave
region. I'm still not sure of the electrical characteristics of the
varous insulating foam boards. I did best (so far) using common
Styrofoam, glue, and aluminum foil. Also common stationary store sign
board material. Lots of foam board types out the
http://www.rigidfoammachining.com/rigid-foams.html
The hard part is figuring out which type of foam your favorite
insulation uses and what the manufactory has added. I found one brand
that has some kind of anti-static conductive additive added to prevent
the foam board from turning into a big capacitor and zapping the
installer. Kinda marginal for an antenna. Be careful and do some
measuring.

However, you're not going to do well with HDTV and patch antennas.
Unless you're building a single channel TV antenna, the patch antenna
is just too narrow band to be useful. It's also difficult to build
complex structures on home insulating foam. The patch size will be
rather huge to cover the lower VHF frequencies.

Good idea for a fairly narrow band patch antenna, but HDTV is the
wrong application.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558