I have used one for years. If adjusted no need for an ATU.
The dipole elements are matched by using twin speaker wire with a short
across both wires at particular distances, and only fed onto one the
pair, the other is a straight unbroken connection.
Inside the feed box of the G3TPW made antennas is a coax choke so no
need for an external choke or balun. I've worked over 200 DXCCs with
that antenna, at the moment I have one mounted at 35 feet and it works
really well. See www.m0pcb.co.uk for photos.
73, Iain M0PCB
On 31/05/2013 17:00, [email protected] wrote:
Message: 8
Date: Thu, 30 May 2013 22:51:59 -0500
From: Tony Estep<[email protected]>
To: Elecraft<[email protected]>
Subject: Re: [Elecraft] cobweb antenna
Message-ID:
<cachwrmo7wvy6ejcx4p1u3vu_odyyfvqoevsn1fxkx38wvaq...@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
On Thu, May 30, 2013 at 9:47 PM, Lee Stephens
<[email protected]>wrote:
>....never heard of the 'Cobweb' but....
===========
Well, it's really the same thing as a halo, which in turn is the same thing
as a dipole that's been bent into a circle (or in this case a square) and
trimmed so that it's resonant after taking account of the proximity effect
at the ends. It emits horizontally polarized radiation in all directions,
and generally works fine. Several can be combined for an all-bander (see
http://www.g3tpw.co.uk/). If fed with coax, it will benefit from a coaxial
choke mounted near the antenna.
Tony KT0NY
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