Maybe the only one? :-) The G5RV, with tuner, is a pretty
good 80m, 40m, 20m, and 12m antenna.

Depends what you compare it to... I bet my paralleled
80/40/20 dipoles would beat it on all those bands.
Maybe even 12m. I'm not going to lose too awful much
even though I'm running 213 coax. You may have some
cases on the higher bands where the gain may be
better than the dipoles in some directions, but thats still
not a matter of efficiency.

If the series section
is varied from 20 feet to 36 feet, it becomes a very good
all-HF-band antenna. With the addition of a parallel 1000pf
capacitor with the series section at 22 feet, on 75m my "G5RV"
has SWR of 1.3:1 and works as well as a 75m 1/2WL dipole.

You would be the exception to the rule. And I still really doubt
it's the total equal of a simple coax fed dipole on 80m.
The "usual" G5RV that most people tend to buy and run
is one of the most pathetic 80m antennas I've ever used
in my life. Truly a disgusting POC... I had the mispleasure
of being stuck on the G5RV at not one, but two field days
in a row. I'd never experienced working FD on a dummy
load until that time. I lost about 3 mm of tooth due to the
constant grinding of my teeth on those weekends.
After that, I *swore* I would never, ever, be stuck on
one of those things ever again. Never, nada, zilch.
Now, I've heard people that had fairly decent signals
with various perversions of the G5RV, but again, they
seem to modify them to work halfway well, and many
run amps, which also help them look a bit better than
they really are. If people want to run those, be my guest,
but keep them at least 500 yards from me. I'll be using
my usual coax fed dipoles.
This trails off to the "carolina" windoms that many people
run in the same appx manner.
Well, on the first FD after the two G5RV nightmares,
I brought all my own stuff to build dipoles on the spot.
I got to the FD, and the first antenna they suggested I
use was a carolina windom that was up in the air
pretty well. Maybe 50 ft up or more. It was fed with
the usual "clutter" and a tuner. "tuner/coax/choke/antenna.
I can't remember if any ladder line was involved on
that one...
Anyway, the first thing out of my mouth was *NO!!!!!".
I'll build a regular ole dipole, thanks, but no thanks.
Not trying to be rude, but I'd had my fill of dummy loads.
Anyway, I built a 40 meter dipole on the spot, and
threw it up in a different tree. It was actually lower
in height than the windom. I then brought out a coax
switch, and hooked both the windom, and the coax
fed dipole to the rig. Now, at first glance, you
would think the windom was doing all the good.
It was "working", and seemed to be just fine.
But then, I'd switch over to the dipole, and
*everything* would jump 2 S units on that radio.
All signals, noise floor, the whole shooting match.
The windom owner like to fell over. He had no
idea that he was taking that big a hit vs a simple
dipole. Needless to say, the windom wasn't used
after that test. People can run whatever they want,
but many have delusions that these "compromise"
clutter fed all band antennas are just as good as a
simple dipole. It's rarely the case by what I've seen.
Did you actually compare with a coax fed dipole
using a switch, etc? If not, saying it's equal is
just theory at this point. I'd have to see it to believe
it... :/ Heck, I see the difference from a properly fed
tuner/ladderline/dipole setup vs a coax fed dipole.
The coax fed always wins here by a slight amount.
As far as I'm concerned, a coax fed dipole is as good
as you can get in the real world on those lower bands as
far as system efficiency. In the 95+% bracket I think.
Your tunerless setup may be equal, but that's
not the usual setup for most people. Most use
a tuner also. I use the coax fed dipole as the benchmark
by which all others are measured on 80m. Most all lose,
unless they are a gain antenna like arrays or whatever.
Of course, with the dipoles on 80m, I'm usually talking
NVIS, or medium distances. I'm not a dxer much.
But...I had no problem at all taking to EU this past
winter on that dipole in the couple of times I tried
it down in the dx window. . No amp. I haven't run an amp
in 5 years. First call and solid copy too. I forgot where
they were. I think one on G land. One in Spain, germany,
etc..With just 90-100w from the 706. But a big NVIS
signal is really what I shoot for. Can't get much better
than a coax fed dipole or loop. Simple is best I think.
MK