How long does the tree last after topping? Won't that kill it?
Do you install steps for future access for maintenance?
How about using a Ring Rotor -- anyone tried this?
I have lots of 80 ft. pines....
At 08:16 PM 9/6/02 EDT, you wrote:
>In a message dated 9/6/02 5:00:39 PM Pacific Daylight Time,
>> Does anyone out there have any experience with mounting a rotatable yagi
>> to a tree? I've been told this is (or used to be) common in the Pacific
>> Northwest. I'd be interested in hearing:
>> 1) How to calculate a safe load
> Calculate? How would you come up with a formula for the tree capacity?
> I've installed 14-15 antennas in trees including HF yagis and 2L 40M
>beams so I have a professional perspective but don't have any numbers to
> I usually top the tree when it's about 10 or so inches in diameter. How
>strong is an 8x8 piece of wood? Pretty danged strong actually.
> If you're talking about an HF beam, I wouldn't go any larger than
>16' or so boom - the forces just get too big.
> The other limiting factor is rotator capacity since I pipe mount the
>rotator and then the antenna on top of it. I prefer the T2X since it has a
>lot of mast mounting capacity and will twirl just about anything small to
>moderate in size for a long time.
>> 2) How to fabricate a suitable mount
> I use a piece of galvanized pipe (1-1/2" ID = 1.9" OD) with a horizontal
>piece welded to it (picture a cross). The horizontal ends are bolted to the
>tree as is the vertical pipe. The rotator goes on top of the cross. I use
>1/2" lag screws on the vertical pipe - 3-4 of them - and screw them right
>into the tree. The antenna will blow away before the mount fails.
> A BIG advantage for a tree installation is that it's UNREGULATED when it
>comes to building departments! I charge a lot for them because they're dirty
>and a lot of work.
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