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Re: Topband: Magnetic Receiving Loop 160m

To: Petr Ouøedník <indians@seznam.cz>,<topband@contesting.com>
Subject: Re: Topband: Magnetic Receiving Loop 160m
From: "Tom Rauch" <w8ji@contesting.com>
Reply-to: Tom Rauch <w8ji@contesting.com>
Date: Tue, 20 Dec 2005 16:51:32 -0500
List-post: <mailto:topband@contesting.com>
> - highly recommended is K9FD version inspired by ARRL
Antenna Book (i.e. 1982) at
http://www.ok1rr.com/view.php?cisloclanku=2004122907

There is an unorthodox connection method shown at that site.
While the loop might indeed receive signal, this would not
be a very desirable connection arrangement.

If you look, the inner wire make a complete circle with both
ends tying to the feed.

The result of this is unbalanced currents caused by physical
imperfections would primarily excite the feedline, not the
desired predictable loop currents!

A better arrangement would be the inner conductor grounded
to the loop shield at the return point through a capacitor,
so the parallel capacitor causes a high impedance parallel
circuit across the coax and the capacitor to ground causes a
series effect. The ratio of those two capacitors in
combination with resonating the center coupling wire would
set the SWR. The other circuit may work after a fashion
through accident, but it would depend on having accidental
balance errors to work.

73 Tom

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