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Re: Topband: question about antenna bandwidth

To: Roy <royanjoy@ncn.net>
Subject: Re: Topband: question about antenna bandwidth
From: DAVID CUTHBERT <telegrapher9@gmail.com>
Date: Mon, 7 May 2012 16:37:28 -0600
List-post: <topband@contesting.com">mailto:topband@contesting.com>
Roy, you didn't specify the vertical length of your inverted-L but I'll
assume it is 50' and that your base-referred ground loss is 5 ohms.

Using NEC-2 for the 1/4 wavelength inverted-L I get a 2:1 VSWR bandwidth of
51 kHz. Note the base resistance at resonance is 18 ohms.

For the 3/8 wavelength inverted-L I get a 2:1 VSWR bandwidth of 30 kHz.
Note the base resistance is 44 ohms and a 142 pF series capacitance is used
to tune out the inductive reactance.

    Dave WX7G


On Mon, May 7, 2012 at 11:48 AM, Roy <royanjoy@ncn.net> wrote:

>
>
> > If I were to extend my 1/4-wave inverted-L to a 3/8-wave L, and tune
> > out the inductance with a fixed capacitor at the base, what would this
> > do to the broadbandedness of the antenna?
>
>
> There is an old basic principle to remember about this, "The fewer the
> components in general, the broader the bandwidth."
>
> 73,   Roy   K6XK
>
>
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