From: John De Armond
Newsgroups: rec.outdoors.rv-travel
Subject: Re: Sat_ellite Dish Wifi
Date: Fri, 23 Dec 2005 14:06:39 -0500
Message-ID: <qbioq11k2jqnlj2bpdavsv1scu58gb3qgs@4ax.com>

On Fri, 23 Dec 2005 10:21:50 -0500, "Cliff" <cliffclingan@hotmail.com>
wrote:

>
>> http://www.oreillynet.com/cs/weblog/view/wlg/448 if you are
>> interested in building your own.
>> FMB
>
>   How tall would the antenna have to be to see over the horizon?  Enquiring
>Minds ...

Not height.  Power.  In Thule Greenland, it required about 80kw of 900
mhz RF into a 135 foot square billboard reflector aimed at the horizon
to carry about 500 telephone channels via tropo scatter.

I've achieved tropo scatter communications on the 1200 and 2235 mhz
ham bands with about 500 and 5k watts ERP respectively, over a much
shorter distance.  Tropo scatter is very handy for getting short
wavelength RF over hilltops and such.

Tropo scatter is the RF equivalent of the light you see scattered off
the beam axis of a bright light beam by the atmosphere and suspended
dust.

John