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