Thanks everybody for the comments, and working my way back up the
thread:

RHF - Dipoles are outside. The 160m dipole is about 250 feet from end
to end and is more of a sloper than a true dipole. I center fed it
with some very nice coax on my roof and strung ends out on the corners
of my property. I operated a few watts into Canada last year using
the world famous N9-NEOphyte. (A very clever and novel design to make
nice AM waves.) Maybe this winter a few hundred watts.

http://mysite.verizon.net/vze6qsvc/coolradiostuff22/

The reason for playing with another antenna is just that. I want to
experiment. I have trouble sleeping at night knowing there is an
unused coax run from the attic directly into the shack. Surely you guys
can understand that.

The Horizontal loop is going to be a contender for sure. I like quiet
and many times have turned the radio off because of the static crashes.
I could easily hang it up in the attic.

Mr Lector's link to antenna site led me to a T2FD which is a folded
dipole of sorts. This would also be a contender. It may have a wider
bandwidth that the 300 ohm folded dipole. I've been told the US NAVY
says it's a good antenna.

And Mr Telamon, I have some ferrite material here that I might be able
to wind something on in the way of a Balun. Some #43 or maybe #61
material I think. The cores are a little large, but may end up being
very good. I don't think the microvolt level signals would be lost
trying to excite a larger core. Have to mull that over some I suppose
I would want Xl to be a multiple of the 300 ohms at the lowest
operating frequency. Care to take a whack comparing the folded dipole
to the horizontal loop and the T2FD?

Thanks again for comments. I'm looking forward to some experiments.

73
Bob
N9NEO