Message-ID: <39408E1C.3CC76A10@virgin.net>
Date: Fri, 09 Jun 2000 07:26:36 +0100
From: "Stewart Bryant" <stewart.bryant@virgin.net>
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To: rsgb_lf_group@blacksheep.org
Subject: Re: LF: Re: Aerial tests.
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Dick Rollema wrote:

> To All from PA0SE
>
> Walter Blanchard quoted the RACAL expert who has in the past  designed the
> Decca antennas as follows:
>
> >(...)  If the small one has an assymetric horizontal component (flat-top)
> > this will complicate matters considerably since it will radiate both
> > vertical and
> > horizontally-polarised and there will be interaction between them that
> > will affect the radiation pattern. So it would be unlikely to have a
> circular
> > polar pattern and this might account for some of the observed variations.
>
> This is not confirmed by computer simulation.
>

Shouldn't you say "Computer simulations do not model this". Decca did a lot of
measurements when they developed Navigator, and the physics always has the last
word. The question should therefore be "what is wrong with the computer model?"

Stewart G3YSX