John N9JG wrote:
I live in a two-story slab house with aluminum siding on the walls. Has
anyone had any experience with mounting an external transmitting loop
antenna (for 80 or 160 m) near aluminum siding? I am guessing it is not
recommended, but I would be interested in any comments about this topic.

Hi John, Since it is not recommended to mount a loop antenna or any
other kind, near aluminum siding, I doubt many here have done so. May
not get comments about doing the undesirable.
On the other hand, a 160m full wave loop will be so large in
comparison to the small section that is in proximity to the aluminum
siding, you may not be able to tell much difference whether the siding
is there or not. Same thing with a full wave 80m loop. I would go for
it.
Gary N4AST