wrote:

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.

Not by enough to notice on the other end. The G5RV has
a slight amount of gain over your 40m dipole. It has
low loss on the ladder-line matching section and an SWR
of less than 4:1 on the RG-213 coax. Where are the losses?

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.

It's a 3/8WL dipole on 75m, fed with low-loss ladder-line,
a parallel door knob cap, and an SWR of 1.3:1 on the RG-213
coax. Where are the losses?

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.

Well, maybe. The one I bought in 1988 was well designed with
a w2du balun and RG-8x coax. It worked well with a tuner and
I made lots of improvements as I learned more about it.

There was probably something wrong with the particular G5RV's
that you have been exposed to.

Some people run a 4:1 balun at the coax/twinlead junction on
a G5RV. That's the absolute worst thing to do on 75m as the
impedance at that point is already low at 16 ohms.
--
73, Cecil http://www.qsl.net/w5dxp

Depends what you compare it to... I bet my paralleled
80/40/20 dipoles would beat it on all those bands.

Not by enough to notice on the other end.

So you say. If I can tell the difference between a tuner/
ladderline fed dipole vs a coax fed dipole, I bet I could
tell the difference. But I use the receiver, and switch
between the antennas. Much more accurate than
relying on reports.

The G5RV has a slight amount of gain over your 40m dipole.

That just means I'm almost sure to be louder in the
other two directions.. :/

It has
low loss on the ladder-line matching section and an SWR
of less than 4:1 on the RG-213 coax. Where are the losses?

At the ladderline/choke/coax junction I would suspect.



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.

It's a 3/8WL dipole on 75m, fed with low-loss ladder-line,
a parallel door knob cap, and an SWR of 1.3:1 on the RG-213
coax. Where are the losses?

Does that version use the choke? Being the data is incomplete,
hard to say at this point. But if there is loss, I can probably
find it.. :/

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.

Well, maybe. The one I bought in 1988 was well designed with
a w2du balun and RG-8x coax. It worked well with a tuner and
I made lots of improvements as I learned more about it.

Hummm...Does that mean it's not really a G5RV anymore?

There was probably something wrong with the particular G5RV's
that you have been exposed to.

No doubt about it.

Some people run a 4:1 balun at the coax/twinlead junction on
a G5RV. That's the absolute worst thing to do on 75m as the
impedance at that point is already low at 16 ohms.

I bet those did use a 4:1...Kinda makes sense as they were
the absolute worst wire antennas I'd ever used on 80m.
But like Owen points out, you have so many perversions
of the G5RV, it's hard to tell what is what. I *think* the
versions I used were made by the same company that
makes the carolina windoms, but not sure. I don't
really keep up with antennas I know I'll never be using.. :/
What boggles my mind is why people would want to use
a compromise antenna at a field day, when you have
enough room to fit 49 full size antennas... :/
Or at home for that matter.. If I have room for full size
antennas, I'm gonna use them. Life is too short for
compromise antennas. I guess I'm spoiled. I've never
had to run those funky things due to lot size, etc..
Even if I did, I think I could cook up something better
than the usual G5RV. Whatever I use will never mix
feedline types midroute to the antenna, I know that
for sure. It's like a crapshoot hoping things will pan
out at the junction. I couldn't live that way.
MK

wrote:

W5DXP wrote:
It has
low loss on the ladder-line matching section and an SWR
of less than 4:1 on the RG-213 coax. Where are the losses?

At the ladderline/choke/coax junction I would suspect.

The only thing there that could be lossy would be the choke.
Why would a 1000 ohm choke be lossy?

It's a 3/8WL dipole on 75m, fed with low-loss ladder-line,
a parallel door knob cap, and an SWR of 1.3:1 on the RG-213
coax. Where are the losses?

Does that version use the choke? Being the data is incomplete,
hard to say at this point. But if there is loss, I can probably
find it.. :/

Yes, but the impedance at that point is very close to 50 ohms
and the choke has about 1000 ohms of choking impedance.

Well, maybe. The one I bought in 1988 was well designed with
a w2du balun and RG-8x coax. It worked well with a tuner and
I made lots of improvements as I learned more about it.

Hummm...Does that mean it's not really a G5RV anymore?

Call it a modified G5RV. It still looks like a G5RV.

Whatever I use will never mix
feedline types midroute to the antenna, I know that
for sure. It's like a crapshoot ...

Not a crapshoot at all - just an application of a series section.
Do you object to 1/4WL of 75 ohm twinlead feeding a full-wave loop?
--
73, Cecil http://www.qsl.net/w5dxp

Not a crapshoot at all - just an application of a series section.

I'm not really talking about yours though. I'm talking about
the "usual" G5RV that is fed with a tuner, etc, ad nausium.
Most people don't change sections when they change
bands. They just redial the tuner and go.
If you change very much with a G5RV, it's not a G5RV
anymore. IE: If you feed a 102 ft dipole with ladder
line, but no choke or coax, it's not a G5RV anymore.
It's a 102 ft dipole fed with ladder line.
A series transformer for a loop is not quite the same to
me as it's almost always a single band solution.
I won't be expecting that transformer to work for all bands.
Like I said, if the "G5RV" or others of it's ilk are appealing
to you, be my guest. But trying to talk me into using one,
or even accepting it as something I would actually use is
futile. :/
Tell me this...What is the advantage of using the choke,
coax, etc, vs just running straight ladder line the whole
way? If I had to tuner feed a 102 ft dipole for all bands, thats
the way I would do it. There would be no coax, or choke.
MK

wrote:
If you change very much with a G5RV, it's not a G5RV
anymore. IE: If you feed a 102 ft dipole with ladder
line, but no choke or coax, it's not a G5RV anymore.

But that's exactly what G5RV recommended as one form of
his G5RV antenna.

Tell me this...What is the advantage of using the choke,
coax, etc, vs just running straight ladder line the whole
way?

The advantage is a pretty good match on 80m, 40m, 20m and
12m that's not guaranteed with straight ladder-line. Some
lengths of ladder-line present additional problems. For
instance, if one happens upon a current maximum point
located at a 4:1 balun, one can take 16 ohms down to 4
ohms. That's going in the wrong direction.
--
73, Cecil http://www.qsl.net/w5dxp