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Re: [TenTec] Capture area (was 80 meter loops)

To: <tentec@contesting.com>
Subject: Re: [TenTec] Capture area (was 80 meter loops)
From: "Michael Tope" <W4EF@dellroy.com>
Reply-to: tentec@contesting.com
Date: Fri, 19 Mar 2004 20:49:19 -0800
List-post: <mailto:tentec@contesting.com>
> If the wavelength is known, as it normally is,
> then effective area can be calculated from isotropic gain,
> and vice versa:
>
>   Ae = Gi * lambda ^ 2 / (4 * Pi)
>
>   Gi = 4 * Pi * Ae / (lambda ^ 2)


Actually Sinisa, you just made my point. If you know the
effective aperture of the receive antenna, then you can
do the calculation of received power straight away. If
on the other hand you know the gain of the receive
antenna, you have to convert it to effective aperture in
order to do the receive power calculation. This conversion
is imbedded into the Friis transmission formula which
introduces the bogus non-physical concept of wavelength
dependent "path loss" to account for the variation in the
effective aperture of a constant gain receive antenna as
a function of wavelength.

73 de Mike, W4EF..........




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