On Fri, 09 Jul 2004 02:20:18 -0400, jdurling@bellsouth.net (Jeff
Durling) wrote:
>Actually if you built a omni form one of the websites that specialize
>in outdoor wireless antennas and got an amplifier you should have a
>range of about 15 to 20 miles. Without the amplifier but a proper setup
>((hight around 20') you will se in the range of 5 miles. The trees are
>somewhat of a limiting factor but the leaves themselves pose no
>problem. Actually the trees aren't really that big of a problem either,
>it's hills and valleys that can cause problems. You could also do the
>same with a parabolic mesh antenna if you want the signal in a specific
>direction. It will spread out in a V side to side but be totally blind
>on the reverse side of it.
Not true. Parabolic dish antennas also radiate the signal out the
rear of the dish. Not nearly as far or as concentrated, but for
shorter links, you can easily enroll clients in the back of a
directional antenna... particularly parabolic dishes.
>A year ago I didn't know jack now since my company was setting these up
>in our Brasil operation for clients I am learning quite a bit. The
>amazing thing the antennas are not that expensive. A good Parabolic
>will run around $45 - $65 not including cable and a good Omni will run
>about double. The amplifier is supposed to only be sold to goverment
>approved but they are not that hard to get. As long as you are not
>trying to blast someone's network or are monitoring it they will never
>bother you. Being rural is even a better choice here. remember you
>don;t really need the amp unless you need a better signal.
Well, the legal aspect isn't really that difficult to overcome. The
5W and 10W amps are floating around all over the place. The real
problem when you couple (relatively) high wattage amps like that with
high gain antennas (i.e. a 24db gain parabolic dish) is the effective
radiated power that you create. Obviously, the more the better if
you're trying to get the signal far away, you can pretty easily build
something that puts out a level of power that's unhealthy for the
human body to be exposed to for long periods of time. In other words,
if you had a 5W amp on a 24db gain antenna, I would not want to sleep
underneath it, even if it were on a 20' mast :-)
-Bill
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