several have asked how I am measuring the impedance.....I'm using an AA-230,
and am all the ALL PARAMS setting.....the 230 defaults to a series model, is
that what I want, don’t see how to change it to parallel. I think the symbol
for impedance is |Z|, correct?
-----Original Message-----
From: F Z_Bruce
Sent: Sunday, November 18, 2018 3:20 PM
To: wes_n7ws@triconet.org ; Topband
Subject: Re: Topband: Impedance of inv l?
The far end is high impedance voltage, and has minimum horizontal
current radiation. The inverted L is a good trade off signal vs
available height. Not an expensive antenna to build.
73
Bruce-k1fz
On Sun, 18 Nov 2018 12:31:38 -0700, Wes Stewart wrote:
That also drives up the current in the horizontal wire with attendant
increased
horizontal radiation.
I chose for a couple of reason to do the opposite; shorten the wire to make
the
feedpoint capacitive and use a shunt inductor to get a 50-ohm match.
This
really doesn't improve the 2:1 VSWR, that I consider acceptable, however.
Wes N7WS
On 11/18/2018 8:55 AM, F Z_Bruce wrote:
> That sounds about right. As you put a good ground system under it, that
value will come down, and the efficiency will come up.
>
> Many add extra antenna wire that pushes the current up the wire, this
also raises the impedance, hopefully to near 50 ohms with the right
length.
> A capacitor (variable, then fixed) in series at the feed point can
cancel the added inductance.
>
> 73
> Bruce-k1fz
> https://www.qsl.net/k1fz/beverage_antenna.html
>
>
> On Sun, 18 Nov 2018 10:41:36 -0500, WW3S wrote:
>
> What should the Z be for a 1/4 wave inv l, with the radials attached to
a radial plate? Mine seems to be 60 ohms or so....
>
> Sent from my iPad
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