Return to KLUBNL.PL main page

rsgb_lf_group
[Top] [All Lists]

Re: LF: Re: 73KHz beacon

To: [email protected]
Subject: Re: LF: Re: 73KHz beacon
From: "gii3kev" <[email protected]>
Date: Mon, 01 Oct 2001 17:36:32 +0100
Organization: Netscape Online member
References: <[email protected]> <[email protected]> <[email protected]>
Reply-to: [email protected]
Sender: <[email protected]>


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





<Prev in Thread] Current Thread [Next in Thread>