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 Sent: Wednesday, February 17, 2016 2:13 PM To: [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]> 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]> wrote: Ponderosa? Fir? Cedar? The length of the needles matter. From: Rory Conaway Sent: Wednesday, February 17, 2016 12:51 PM To: [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. 37th Street • Phoenix • AZ 85040 602-426-0542 [email protected] www.triadwireless.net “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 -- -- Sam Lambie Taosnet Wireless Tech. 575-758-7598 Office www.Taosnet.com
