Tom:

Go ahead with the loop.  If you have the space and supports, just do a 
horizontal loop of covering as much area as possible.
An 80 meter loop would be a square of about 67 feet per side. If not square, 
that's ok.
This will be nearly omnidirectional, quiet, and work like gang busters.
I've got to get mine up.
Used a 400 foot circular loop for field day one year.  Worked all I could 
hear using 5 watts and cw.
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