Content-Transfer-Encoding: 8bit
Message-ID: <3.0.1.16.20000218124330.2ebf3f0e@mail.cc.kuleuven.ac.be>
Date: Fri, 18 Feb 2000 12:43:30
To: rsgb_lf_group@blacksheep.org
From: "Rik Strobbe" <rik.strobbe@fys.kuleuven.ac.be>
Subject: Re: LF: Inverted V on LF?
In-reply-to: <F5AFD56E32E8D21191090060974838B1487FA8@ulm003.vs.dasa.de>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii; format=flowed
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org
Sender: <majordom@post.thorcom.com>

At 10:39 18/02/00 +0100, DL1SAN wrote:
>I thought about an symetrical antenna for LF. The antenna could be an
>inverted V arrangement with a length of 2 X150 m. A practicable hight is
>about 20m for the feeding point. Has anyone experience with this kind of
>antenna? What is the difference to a marconi system or a top loaded
>vertical?
>May be this is a stupide question. Even so....

Main difference is that a marconi antenna (with or without toploading) has
vertical polarisation while a short horizontal dipole (300m = 0.14
wavelengths) will be horizontal polarized.
In all LF handbooks you find that a horizontal polarized antenna is rather
useless because :
1. you will have no surface wave (as you need a vertical polarized signal
for that).
2. for horizontal polarized antennas at very low height (20m = 0.009
wavelengths) the signal will be 'canceled out' by reflections at the ground
(or by the 'mirror antenna' that is at 20m below the ground and is in
counterphase with the real antenna)

But this last may only be partially true as ground is far from perfect at
most 'amateur locations'.
The only way to find out wether it works or not is to try it.

73, Rik  ON7YD