Message-ID: <3BB89B8F.93507C9F@netscapeonline.co.uk>
Date: Mon, 01 Oct 2001 17:36:32 +0100
From: "gii3kev" <gii3kev@netscapeonline.co.uk>
Organization: Netscape Online member
MIME-Version: 1.0
To: rsgb_lf_group@blacksheep.org
Subject: Re: LF: Re: 73KHz beacon
References: <3.0.1.16.20011001084908.2af76e6c@mail.cc.kuleuven.ac.be> <3.0.1.16.20011001105044.2d67661a@mail.cc.kuleuven.ac.be> <3.0.1.16.20011001130655.30f79622@mail.cc.kuleuven.ac.be>
Content-Type: text/plain; charset=us-ascii; format=flowed
Content-Transfer-Encoding: 8bit
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org
Sender: <majordom@post.thorcom.com>


Rik Strobbe wrote:

> >Rik, thanks for the explanations.
> >I would have never imagined that the gain provided by having a radiation
> >diagram 'squeezed' in the vertical plane could more than compensate for
> >the losses caused by the very short dimensions (compared to the wavelength)
> >of the antenna.  Today I learnt a new one. TNX.
>
> Hi Alberto,
>
> If an short vertical monopole is placed over perfect ground and brought to
> resonance with a perfect loadingcoil there are no losses, so its
> performance will be independent of its length. It looks a bit strange at
> first sight but in the perfect world there are no losses and so every mW
> you put into the antenna will be radiated regardless wether the antenna is
> 1m or 100m high.
> Unfortunately there is no perfect ground and no lossless loading coil so in
> practice (on 136kHz) a longer antenna will outperform a shorter and the one

What I have been saying all the time and I am glad you and others realize this
at LAST!!!!


>
> who can put a lambda/2 dipole at lambda/4 height will have the
> super-antenna (but this antenna just doesn't fit in my back yard).
>
> 73, Rik  ON7YD