As the son of a gardener, I'd be surprised if something that simple would
kill a tree.
On Fri, 6 Sep 2002, Jon Zaimes AA1K wrote:
> Steve,
>
> 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....
>
>
> 73/Jon AA1K
>
> At 08:16 PM 9/6/02 EDT, you wrote:
> >In a message dated 9/6/02 5:00:39 PM Pacific Daylight Time,
> >kellyjohnson@telocity.com writes:
> >
> >> 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
> show
> >you.
> >
> > 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
> about a
> >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.
> >
> >Cheers,
> >Steve K7LXC
> >TOWER TECH -
> >Professional tower (and tree) services for commercial and amateur
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> _______________________________________________
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> Call 888-333-9041 to place your order, mention you saw this ad and take an
> additional 5 percent off
> any weather station price.
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--
Hisashi T Fujinaka - htodd@twofifty.com
BSEE (6/86) + BSChem (3/95) + BAEnglish (8/95) + $2.50 = mocha latte
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