In one of Beverage's old articles, there is a page or two devoted to adding
coils to lower the velocity of the antenna.
If I recall correctly, it has both theory and measurements.
Chuck
________________________________
From: Topband <topband-bounces@contesting.com> on behalf of Mikek
<amdx@knology.net>
Sent: Thursday, November 21, 2019 12:13 PM
To: topband@contesting.com <topband@contesting.com>
Subject: Topband: BOG Beverage on Ground Help
Hi guys,
Just saw this page and it presented info that a BOG is a resonant
antenna. It gives me a little boost
about adding inductance to the antenna to artificially lengthen it.
> http://www.iv3prk.it/bog-modeling.htm
Is there any agreement about this or anyone want to shoot it down?
Mikek
Hi guys,
I see certain measurements for the length of a BOG, such as 200ft for
for 160 meters.
And even a warning on one page,
/*
"The biggest mistake is making the BOG antenna too long. Try not to go */
/*over 200 feet for 160 meters."
*/So, if I tried to use this 200ft BOG on 80 Meters, I assume it has
receive problems.
A short explanation of those problems would be helpful, Impedance? Pattern?
I've been pondering over W8JI's Loaded beverage page.
> https://www.w8ji.com/slinky_and_loaded_beverages.htm
I'd like to apply the loading to a BOG to slow the VF and make it seems
longer.
ie. make a 80 meter BOG length work on 160 Meters. But then make the
reactance go away for 80 Meters
My actual goal is to have a BOG that covers 500kHz to 4MHz.
To that end, I have been working on a variable inductor that I can
insert into the length of the BOG.
In reality, it would be eight Variable inductors spaced about 35 to 40ft
apart. I'm land limited to about 270ft.
I want to control the inductors with a DC current through the BOG wire.
I have a 100uh toroid inductor that I can partially saturate with an
electromagnet.
The electromagnet is energized by an adjustable current through the
BOG wire. This means I need
to RF bypass the Electromagnet, so it's inductance is not seen by the
RF. Also I must block the RF
from seeing the Power supply/current source.
I have a drawing showing my proposed circuit here.
> https://www.dropbox.com/s/wrfpubqvsfd11nq/bog%20with%20variable%20inductors..jpg?dl=0
I want to be told what problems you see and ways to overcome them. _If
it is at all feasible_,
I would wonder about the values of the blocking caps and Chokes.
I appreciate any thought you can give this idea.
Mikek
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