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Re: Topband: inverted L fed with coax

Subject: Re: Topband: inverted L fed with coax
From: Brad Rehm <>
Date: Tue, 16 Jun 2009 13:22:26 -0500
List-post: <">>

My inverted-L has the same dimensions as the one you describe.  It's
installed on a pole so that the base is about 9 feet above ground.
Four above-ground radials serve as the counterpoise.

I feed with coax but it's matched to the antenna with a simple
transmission line UNUN.  The antenna feed impedance is about 22 Ohms
with less than 10 Ohms reactive, so feeding with coax would give you a
little over 2:1 VSWR.  You should easily be able to match this with a
tuner in your shack.

The UNUN yields a VSWR of about 1.2:1 at 1820, so most of the time I
don't use a tuner.  VSWR is under 1.7:1 from the bottom of the band to
about 1835.

If you don't have a tuner, you might check Jerry Sevick's books.  He
gives a design example of a 2.25:1 UNUN in one of his later volumes.

Hope this is helpful.  Good luck!

Brad, KV5V

On 6/15/09, <> wrote:
> Would like to hear of people's experiences, if any, with feeding an inverted
> L directly with coax.
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