Only the surface anodizing is an insulator. Radio frequency-wise, it
may just as well not be there leaving the high conductivity aluminium
siding to behave as if the anodizing didn't exist.

If the siding was covered with a 3" layer of plastic it still wouldn't
make any difference.
----
Reg, G4FGQ

=================================

"John N9JG" wrote in message
...
I appreciate your comments very much; clearly you have had a lot of
experience with antennas. There was one question in my mind about
aluminum
siding in contrast to plain aluminum; it is my impression that
aluminum
siding is anodized, and anodized aluminum is an insulator. If my
impression
is correct, would that make any difference in the interaction
between a loop
and the siding?

"Reg Edwards" wrote in message
...

Aluminium is a good conductor, nearly as good as copper.
Negligible
loss will be induced in it. Most loss will be in the ground by
virtue
of its very low height. The close proximity to ground will also
cause
unoticeable detuning.