I may set up a test for this in couple weeks.

Rory

From: Af [mailto:[email protected]] On Behalf Of Eric Kuhnke
Sent: Wednesday, February 17, 2016 4:41 PM
To: [email protected]
Subject: Re: [AFMUG] Cambium 450i 900Mhz


2.4 in 10 MHz channels goes through a decent amount of trees within 1-2 miles 
max, if all the CPEs are nanobridge m5-25 dishes or similar sized reflectors...

I've seen such setups with clients in trees and signals right around -69 on 
both chains.

Not a lot of aggregate capacity per sector however.
On Feb 17, 2016 2:13 PM, "Sean Heskett" 
<[email protected]<mailto:[email protected]>> wrote:
I've never had any luck with 2.4 going through much more than the side of an 
aspen tree.

can you set up some 900 test shots?

On Wed, Feb 17, 2016 at 3:09 PM, Rory Conaway 
<[email protected]<mailto:[email protected]>> wrote:
So given this scenario, would 2.4GHz be better?  I can use 5GHz inside the 
houses.

Rory

From: Af [mailto:[email protected]<mailto:[email protected]>] On Behalf 
Of Chuck McCown
Sent: Wednesday, February 17, 2016 2:57 PM
To: [email protected]<mailto:[email protected]>
Subject: Re: [AFMUG] Cambium 450i 900Mhz

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. 37th Street • Phoenix • AZ 85040
602-426-0542<tel:602-426-0542>
[email protected]<mailto:[email protected]>
www.triadwireless.net<http://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




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Sam Lambie
Taosnet Wireless Tech.
575-758-7598<tel:575-758-7598> Office
www.Taosnet.com<http://www.newmex.com>


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