Dipole in trees

mass-man

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I have a one time chance to have a dipole installed about 50ft up in the trees. Wondering what might be best for the end supports? Marine grade pulleys that aren't so large the rope works if's way out...coated wire rope around the limb to support the pulley? The antenna itself will be about 96ft, center fed with 450 ohm window line, to a 2:1 balun and LMR 240 thru the attic to the shack.
I've gotta avoid the metal roof on the house with the window line, but that is another day...

thanks all...
 

iMONITOR

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That doesn't sound like a good idea to me. It's like installing an extension cord for running lighting right to your house! Not to mention the trees would likely have an ill effect on your reception.
 

prcguy

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I've done a number of dipoles in trees and I tie a loose black polyester rope around upper limbs to hold a pully at one or each end. The ends of the dipole have black polyester ropes which go through the pully and down to a weight appropriate to hold the antenna taut. I test the amount of weight needed to keep the antenna taut then cast that amount of concrete in a disposable bucket with a large galvanized eye bolt set in the concrete.

Trees move and if you hard tie the dipole to trees they can rip fairly large antenna wire like its kite string during heavy winds. The pullys allow the trees to move and flex without pulling on the antenna wire and they also allow you to take the antenna down without having to climb the tree.

Trees will absorb some RF but a horizontal dipole is usually not a big deal compared to running a vertical right up next to a tree trunk its entire length.
 

mass-man

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Thanks...I’ve done the polyester rope around the limbs before...just wondering if there’s something better? If it breaks I’m not gonna be able to replace it! Counterweights for ends are ready to go...old dumbbell weights! This should be way better than the compromise antennas of my past.
 

prcguy

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Just go big on the rope like 3/4" and make the loop big enough so the tree can grow over time.

Thanks...I’ve done the polyester rope around the limbs before...just wondering if there’s something better? If it breaks I’m not gonna be able to replace it! Counterweights for ends are ready to go...old dumbbell weights! This should be way better than the compromise antennas of my past.
 
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