I never thought of measuring one but Im game. Ill get pics :)
On 2/17/2016 3:57 PM, Chuck McCown wrote:
I have not measured one, but if someone has a pine tree nearby and an
ohm meter, measure the resistance of the needle. Make sure you jam
the probe into the interior of the thing.
I am guessing that the water content of the needle absorbs some of the
RF energy al la a microwave oven. But anecdotal evidence over the
past 10-15 years has shown that pine trees are worse than others so if
the needle itself has a fairly low resistance, like 100 ohms, it is
acting like a dipole with a termination resistor. That is really
going to suck up the signal.
Stealth aircraft have microwave absorbing foam on some of their
surfaces that operate by similar principles.
*From:* Sean Heskett <mailto:[email protected]>
*Sent:* Wednesday, February 17, 2016 2:13 PM
*To:* [email protected] <mailto:[email protected]>
*Subject:* Re: [AFMUG] Cambium 450i 900Mhz
the wavelength of 900Mhz is ~33.3cm so a quarter wave length is
~8.33cm (~3 1/4 inch). Ponderosa pine needles (and many other pine
needles) are around the same 3 1/4 inch length
https://en.wikipedia.org/wiki/Pinus_ponderosa
so with water in the needles you have a big 900Mhz RF
scattering/reflector ;-)
-Sean
On Wed, Feb 17, 2016 at 1:47 PM, Sam Lambie <[email protected]
<mailto:[email protected]>> wrote:
So if you have a minute to please explain how evergreen trees are
terrible on 900 mhz, I would greatly appreciate it.
On Wed, Feb 17, 2016 at 1:14 PM, Chuck McCown <[email protected]
<mailto:[email protected]>> wrote:
Ponderosa? Fir? Cedar?
The length of the needles matter.
*From:* Rory Conaway <mailto:[email protected]>
*Sent:* Wednesday, February 17, 2016 12:51 PM
*To:* [email protected] <mailto:[email protected]>
*Subject:* [AFMUG] Cambium 450i 900Mhz
Realistically, what kind of distances do you get through these
types of trees?
*Rory Conaway **• Triad Wireless •**CEO*
*4226 S. 37^th Street • Phoenix • AZ 85040*
*602-426-0542 <tel:602-426-0542>*
*[email protected] <mailto:[email protected]>*
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**
“The ultimate measure of a man is not where he stands in
moments of comfort or convenience, but where he stands at
times of challenge or controversy” – Martin Luther King
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*Sam Lambie*
Taosnet Wireless Tech.
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