[TowerTalk] Fwd: Re: Antennas in trees

[Jim Brown]

I've tried that with a 40M vertical dipole suspended with the top at 
about 125 ft from a high branch in a redwood next to my house. It 
worked, but a horizontal inverted V with the center at that height blows 
it away in A/B comparisons. Two reasons -- there IS some absorption loss 
for vertical antennas very close to trees, and for verticals in general 
in dense evergreen forests. In general, that absorption increases as a 
function of frequency. I live in such a forest, and the only verticals 
that work well here are for 160M. And even those 160M verticals are 
better than horizontal dipoles because even a dipole at 135 ft, which I 
have done, is a low dipole on 160M. :)

Here are the Power Point slides for some tutorials I've done on this topic.

http://k9yc.com/VerticalHeight.pdf  and
http://k9yc.com/VertOrHorizontal-Slides.pdf
http://k9yc.com/160MPacificon.pdf

73, Jim K9YC


-------- Forwarded Message --------
Subject: 	Re: [TowerTalk] Antennas in trees
Date: 	Sun, 2 Aug 2015 22:27:08 -0700
From: 	Edward McCann <edwmccann at yahoo.com>
To: 	jim at audiosystemsgroup.com <jim at audiosystemsgroup.com>



Ok.

Lots of news from the kinetic energy department.
Lots of folks have approaches to getting their balls over the tree limbs.

Si far only one response as to electromagnetic performance of antennas vertical hanging from he tree limbs.

Anyone else have a story about a vertical dipole hanging from a tree limb not that far from he tree, and working with vertical characteristics, like great do low-take -off angle, etc?

Or vertical half, 5/8, or quarter wave wires hanging from tree limbs?

Thanks

AG6CX



Sent from my iPhone

> On Aug 2, 2015, at 9:03 AM, Jim Brown <jim at audiosystemsgroup.com> wrote:
>
>> On Sat,8/1/2015 4:03 PM, ve4xt at mymts.net wrote:
>> I have no problem getting the line over a nice, tall branch but the arrow and tennis ball get caught up on the way back down.
>
> Here's a useful tool that my Chicago ham club bought and loaned to members.
>
> https://www.youtube.com/watch?v=OIitgJ0M5dk
>
> http://www.sherrilltree.com/Big-Shot-Standard-Kit#.Vb47__lVhBc
>
> http://www.sherrilltree.com/Sherrill-Throwbag#.Vb47W_lVhBc
>
> http://www.sherrilltree.com/BIG-SHOT-Line-Reel#.Vb48NPlVhBc
>
> You will occasionally lose weights. Fishing weights can be used to launch the line, but their visibility is poor, so they're hard to find.
>
> Here's the other popular product, clearly the best. K2RD brought his to my QTH soon after I moved here and cleared the top of a 175' redwood on his first shot.
>
> You can buy replacement weights for both products. Some trees are much worse than others for snagging them. The smaller and smoother they are, the less likely the weights are to snag. It's often possible to "worry" the line back and forth to clear branches.
>
> 73, Jim K9YC
>
>
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