Stefan Wolfe wrote:

I guess in my case, the G5RV is the best I can do. I live in a restricted
PUD but I have a 'relatively' large attic. I could fit a bent 80m dipole up
there or a bent G5RV that is just a few feet shorter. But with the G5RV, I
do get some good performance on several ham bands and I think it is more
efficient than the 80m dipole because the ladder line also functions as part
of the antenna (as you know, according to G5RV theory). . .

There's no theory I know of which causes a G5RV feedline to radiate more
or less than any other dipole. The amount of feedline radiation depends
on the amount of common mode current it carries, and its length. The
amount of common mode current depends on a number of factors, including
how the transmission line is fed, how it's oriented, its length, and the
common mode impedance of the antenna. This is discussed in some detail
at http://eznec.com/Amateur/Articles/Baluns.pdf.

Increasing the amount of vertical radiation and/or having the feedline
radiate doesn't improve the efficiency of an antenna. If you prevent the
feedline from radiating, the power it would have radiated ends up being
radiated by the antenna instead.

Roy Lewallen, W7EL