Hi Pete,
No effect noticed here for leaves with L wire running over tree.
I just reinstalled my 160m Inverted - L on a taller tree (fed 10ft off ground,
80ft vertical , about 52ft horizontal). It's been up all summer with leaves, it
goes over the top of 95ft oak. My vertical wire is #12 THHN, insulated solid
copper. I have 5 tuned radials of the same wire, but thinner gauge is also OK.
I feed it with a 1:1 Balun Designs balun. I trimmed it slightly but it
resonates about 1845 and gives me all the CW band. Tested with Acom 2000A at
1500W out....seems very stable as before mounted on a shorter tree at about
65ft.
Pete, even 1 tuned radial for your L, you should see it working and loading up
OK if you want to test.
I used to easily find the tech supplement online from Butternut for tuned
radials, but it looks like it's now gone.
Check this document out
https://rudys.typepad.com/files/elevated-ground-systems-article-final-version.pdf
. N6LF did some modelling and looks very similar to ON4UN's conclusions in his
lowband book that 4 tuned radials achieve 60% of the efficiency of 100+ radials
on the ground. Some may dispute this, but I've never had enough real estate to
put down a full ground radial field of 100+, but I do have room to put up 4
elevated radials. They can slope, go up and down but if you can, mount them
about 10ft above ground.
The tuned radials are about 3.5% shorter than the 1/4wave element (see the
formula). I cut them all the same as the element, and then gradually shorten
them to adjust for resonance, depending on how the SWR looks.
In the past, the L has worked great for me. I now have about 115 countries
confirmed on 160, all with an L.
73 and best of luck with the project,
Darrell AB2E
________________________________
From: Topband <topband-bounces@contesting.com> on behalf of N4ZR
<n4zr@comcast.net>
Sent: Thursday, August 29, 2019 11:23 AM
To: topband reflector <Topband@contesting.com>
Subject: Topband: Inverted L in contact with leaves
My inverted L is taking shape - about 60 vertical, the rest horizontal.
For a couple of months anyway, it is touching a number of leaves in the
vertical section. I assume that's not a concern, but thought I'd ask
before I get a lot of radials down. First short radial is down and
MFJ-259 results look promising. It's just a problem of waiting for lawn
mowing to stop hi.
--
73, Pete N4ZR
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