Owen Duffy wrote:
My question is how many of these characteristics can be dispensed
with, or varied significantly and still legitimately speak of it as a
G5RV?

Well, with G5RV himself recommending ladder-line all the way
to the transmitter (ARRL Antenna Compendium #1) "If this form
(of the G5RV) is employed, almost any length (of balanced line)
may be used from center of the antenna to the matching network
(balanced) output terminals", the paintbrush is pretty broad.

I started out with a standard G5RV and modified it on a per
band basis to perform on all eight HF bands. 36 ft. of ladder-
line works on both 40m and 17m, my two favorite bands. When I
switch to 75m, I use 23 ft. of ladder-line with a parallel
1000pf cap. I call that the *PC-50* point, the point at which
a (P)arallel (C)apacitor will cause a match to (50) ohms.
--
73, Cecil http://www.qsl.net/w5dxp