I found similar issues on my first center fed zep, wire going through my tall
maple tree, worked great until it rained, or snowed and then finally the wires
seem to grow into the tree limbs itself...making loading changing and effecting
its gain and usefulness......my solution was found at 2 ham fests, for $10 and
$5 I bought old Alpha Delta DX-A slopers, made a dipole out of them ...they are
heavy gauge solid wire with INSULATION on them...thus far the rain doesnt seem
to bother it...tuning remains the same - still fed with open wire feeders into
a Palstar AT1500.
PS>before I found these I was seriously considering making the dipole out of
ladder line, since its all plastic coated, but a bit difficult to pull through
trees...decided on this first.
73, Tim K8WBL
"Everything you want is inside you, All you fear is there as well"
> To: towertalk@contesting.com
> Date: Tue, 14 Jul 2009 00:52:03 -0400
> From: hanslg@aol.com
> Subject: [TowerTalk] Fwd: Trees and Beams
>
>
> I had a LW running though some tree branches. Found that it was impossible to
> get a stable SWR (Used a tuner to get the "right" impedance at the trx end).
>
> Only after removing the offending tree and have about 5 -7 feet to the next
> tree did I experience stable SWR readings.
>
> I am operating 160 - 20 meter on the LW. I believe if I have more than 4 feet
> clearance everything seems OK.
>
> I guess as long as you have clearance so the beam don't get tangled in the
> tree it should be OK.
>
> best 73 de Hans -N2JFS
>
>
>
>
>
>
>
> -----Original Message-----
> From: K7LXC@aol.com
> To: towertalk@contesting.com; wb0m@flashdog.us
> Sent: Mon, Jul 13, 2009 3:28 pm
> Subject: Re: [TowerTalk] Trees and Beams
>
>
>
>
>
>
>
>
>
>
>
> In a message dated 7/13/2009 12:02:17 P.M. Pacific Daylight Time,
> towertalk-request@contesting.com writes:
>
> > Does anyone have any guess on what would be the minimum distance from
> the branches and leaves and from the trunk of a tree to avoid major
> disruption of a signal from a beam antenna up about 30 feet? The tree
> is a silver maple about 50 feet high.
>
> What's a "disruption"?
>
> You've got 2 considerations: electrical and mechanical.
>
> Electrically if it's for HF, leaves and such don't seem to exhibit any
> negatives. For VHF and up, there is probably some signal loss as it goes
> thru wet leaves, trunks, etc. I don't know what the magnitude is but I
> suspect it's slight.
>
> Mechanically any rotatable antenna should be mounted at the top of the
> topped tree in the clear so it'll turn. At that point you're above any
> branches so it's a moot point.
>
> You should leave some branches at the top to keep drawing sap up but
> they do grow and you'll need to do some pruning every 3-4 years to keep
> those little sucker branches from stopping the antenna dead in its tracks.
> It's
>
> amazing how much force they can exert.
>
> Cheers,
> Steve K7LXC
> TOWER TECH
>
>
>
>
> **************Looking for love this summer? Find it now on AOL Personals.
> (http://personals.aol.com/?ncid=emlcntuslove00000003)
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