Buck wrote:
The G5RV is a twenty meter antenna, isn't it? It needs a tuner on all
other bands if I am not mistaken.

The G5RV needs a tuner on all bands. Acceptable SWRs are
very rare without a tuner. The G5RV is 1.5WL long on
20m. The resonant feedpoint impedance on 20m is in excess
of 100 ohms giving a 50 ohm SWR in excess of 2:1 so a
tuner is required, even on 20m. However, I have done to
a G5RV what Fred has done to a 1/2WL 80m dipole. The
matching section on my G5RV is a variable length between
22' and 38'. My G5RV has an SWR below 1.5:1 on all eight
HF bands. I'm going to write it up one of these days.
--
73, Cecil http://www.qsl.net/w5dxp

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On Thu, 09 Jun 2005 06:23:44 -0500, Cecil Moore
wrote:

Buck wrote:
The G5RV is a twenty meter antenna, isn't it? It needs a tuner on all
other bands if I am not mistaken.

The G5RV needs a tuner on all bands. Acceptable SWRs are
very rare without a tuner. The G5RV is 1.5WL long on
20m. The resonant feedpoint impedance on 20m is in excess
of 100 ohms giving a 50 ohm SWR in excess of 2:1 so a
tuner is required, even on 20m. However, I have done to
a G5RV what Fred has done to a 1/2WL 80m dipole. The
matching section on my G5RV is a variable length between
22' and 38'. My G5RV has an SWR below 1.5:1 on all eight
HF bands. I'm going to write it up one of these days.

This is interesting. I remember reading where the G5RV originated as
a gain dipole for 20 meters. I hadn't looked at it as a 1.5wl dipole.
I have always used 1.5wl dipoles for 15 (40 meters) and had low SWR on
the 15 meter band without a matching network. Am i missing something
or is the coax stealing enough power to reduce the SWR?


--
73 for now
Buck
N4PGW

Buck wrote:
This is interesting. I remember reading where the G5RV originated as
a gain dipole for 20 meters. I hadn't looked at it as a 1.5wl dipole.
I have always used 1.5wl dipoles for 15 (40 meters) and had low SWR on
the 15 meter band without a matching network. Am i missing something
or is the coax stealing enough power to reduce the SWR?

Bingo! Your 15m SWR at the 40m dipole feedpoint is probably
above 2:1. Feedline losses both ways probably reduce it to
a value tolerated by your transmitter. If you replace the
coax with an integer multiple of 15m halfwavelengths of
ladder-line to reduce losses, your transmitter may object.

I have inadvertently stepped upon an unpublished article with
my posting. I apologize and will bow out.
--
73, Cecil http://www.qsl.net/w5dxp


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On Tue, 14 Jun 2005 12:38:31 -0500, Cecil Moore
wrote:

Buck wrote:
This is interesting. I remember reading where the G5RV originated as
a gain dipole for 20 meters. I hadn't looked at it as a 1.5wl dipole.
I have always used 1.5wl dipoles for 15 (40 meters) and had low SWR on
the 15 meter band without a matching network. Am i missing something
or is the coax stealing enough power to reduce the SWR?

Bingo! Your 15m SWR at the 40m dipole feedpoint is probably
above 2:1. Feedline losses both ways probably reduce it to
a value tolerated by your transmitter. If you replace the
coax with an integer multiple of 15m halfwavelengths of
ladder-line to reduce losses, your transmitter may object.

I have inadvertently stepped upon an unpublished article with
my posting. I apologize and will bow out.


I find it interesting as it has always been flat. Even better on 15
than 40 most of the time. 2:1 isn't terribly bad, most transmitters
allow it, or close to it before reducing power. What is the impedance
of that?

actually I'll try it on eznec, that's one antenna I can model.

Thanks for the comments.

what's the unpublished article? the G5RV? I don't remember where I
have read it, but then as we have seen here many times, not everything
one reads on the internet (or in the newspaper, for that matter) is
accurate.

DOn't shy away. If you know differently, i am open to hearing it.




--
73 for now
Buck
N4PGW

Buck wrote:
what's the unpublished article? the G5RV? I don't remember where I
have read it, ...

It's somebody else's unpublished article and if it's
"unpublished", of course you haven't read it.
--
73, Cecil http://www.qsl.net/w5dxp

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