Low noise antennas exist and one type is a shielded loop. The noise
improvement is from local noise sources not distant radiating far
fields.

Of course. To me, this proves my point about the antenna in itself. But
again, I don't
consider adding decoupling as making an antenna or even antenna system
"low noise".
That might be an end result to a guy with loads of local noise, but to
a guy in the woods,
it means nada...His noise level in the woods should still be the same.

As far as #1,
1/4 wave Marconi mono-pole electric field sensitive unbalanced., as
being a worst case,
I would think that depends on how it's set up. IE: grounded at the
base, radials, etc as
John mentioned...I never run "incomplete" antennas. Ever...
My 1/4 wave's are not overly prone to common mode problems, but as I
mentioned, if I use a
1/4 wave, it would be properly installed with the lower "half" of the
antenna included,
either as radials, or at least grounded. A balanced coax fed dipole can
be quite bad, if the operation
of the choke, balun, etc is not functioning properly. This would
usually show up more on bands higher
than it's half wave length. IE: Using a 40 meter dipole on 20 meters,
etc..With the hi Z feed on
20m, a usual 1:1 balun would be fairly useless as far as decoupling the
feedline. MK

BTW, if the type on these post's gets goofy, it's cuz I'm using the new
google "beta" and the line wrapping
has changed, and is driving me nuts...It wants to run off the page
forever, unless I manual hit return, and that
drives me crazy. The "old" google, auto wrapped as you typed. Why do
they always
have to mess up something that works perfectly well as is....Or
was...Overall, I don't
like this new google beta much at all.