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Re: Topband: Use shunt fed tower

To: Charles Yahrling <cfytech24x7@gmail.com>
Subject: Re: Topband: Use shunt fed tower
From: Mike Waters <mikewate@gmail.com>
Date: Sat, 15 Sep 2018 11:55:06 -0500
List-post: <mailto:topband@contesting.com>
Hello Chuck,

On Sat, Sep 15, 2018, 11:30 AM cfytech24x7 <cfytech24x7@gmail.com> wrote:

> A shunt fed tower is a vertical antenna so it offers lowest take off
> angle.


True. 160m is a band for vertical polarization if we want to work DX. See
www.w0btu.com/160_meters.html .


Shunt feeding avoids need for radial field.


Sorry, that's just not true. A verical needs an RF ground, something to
"push against". Scroll down this page to see why.
w0btu.com/Optimum_number_of_ground_radials_vs_radial_length.html


But the following is certainly true! :-)


>  Any horizontal wire antenna is going to put most of your radiated energy
> out at high angles, unless you can get it at least a half wavelength of
> height.  A loop may be a quieter antenna for RX but your existing inverted
> Vs are no doubt better for TX.
> There is some art and experimentation involved in the matching but the
> results will be worth the effort.  I  would start with your highest antenna
> for top band, next highes for 80m. Note that your yagis will act nicely as
> capacitive hats to add to effective tower hight.
> Gl es 73, ab1vl chuck
>

73, Mike
www.w0btu.com
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