On Fri, 28 Dec 2007 05:52:37 GMT, "usmcbrat"
<president@[EMAIL PROTECTED]
> wrote:
>Hi All:
>
>I've looked over the content of alt.agriculture.*.* and must say that
it's
>rather sparse, which makes sense to me I guess. The best
farmers/ranchers I
>know are guys who don't give a damn about the internet. But I do have a
>question, and I'll cross post it in alt.agriculture and
>alt.agriculture.technology just to see what happens.
>
>A dear friend of mine who ranches oranges would like to look into some
>thermometer technology. I've taken an interest because I lost 4 of my 5
>yearling avocado trees, and a lemon tree during last winter's cold snap
here
>in the San Joaquin Valley. I looked at "Fruit Growers" in Woodlake,
>California to see what they had, and I wasn't particularly impressed.
Then
>I remembered that I had an old indoor/outdoor thermometer that I had
gotten
>for Christmas a couple of years back, that's called a "Springfield -
>Precisetemp." So I googled around and found some stuff that might
interest
>this friend of mine.
>
>What I've found in the field of RF remotes seems to be limited to about
100
>feet. I'm trying to determine if there's something out there that will
do
>about ten times that distance. I can't do a physical wire because it
must
>cross an asphalt road with no culverts that I know of. We're pretty
handy
>with technology, and might be willing to rig up a solar power supply, and
>even some directional antennae to get the job done.
>
>This is my first venture into looking for some possible solutions.
Thanks
>for your time.
Without knowing the tech too much, I would suggest "data gathering
points" with a small solar array, a battery, a very small computer
with 802.11b or 802.11g (wlan) network and directional antenna.
(Search for cantenna.)
If there are several data gathering points, they should be connected
by a computer with a zone antenna. The smaller the zone, the smaller
effect you need to get good transfer.
Beware that the wireless signals need some space around the clear
sight (freznel zone). Foilage will disstort signals and water(grass,
especialy when wet.) will also spread the signal. Low sun can also
make signals worse.
Since you are dealing with threes, I think the best thing would be to
have some sort of pole attatched to the tree, to get the antennas over
the leaves. If so, you have to pay attention to winds and lightening.
There are good lighening protection available.
Remember that radio-signals are invissible light, and behaves much
like visible light, exept that it goes trough many materials much
easier. If you get yourself a lazer, you should be able to find out
quite a bit by just playing around with that and see where you need to
be to get a signal across.
Just like with a flashlight, the light/signal goes further with the
same amount of energy the more focused the beam is.
--
SEE YA !!!
Trygve Lillefosse
AKA - Malawi, The Fisher King
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