I read somewhere, and can't remember where, that sloping the vertical segment
of the "L" ~15 degrees away from the tower will minimize coupling and loses
into the tower. I have a 140 foot inverted L I use on 160m. It has 60 feet of
vertical suspended off a Rohn 45g tower with about 3 feet of separation at the
top. I sloped it 15 degrees away from the tower in line with but in the
opposite direction of the 80 foot horizontal segment. My radial system is very
minimal with only 16 each, 18 foot radials. With no science to back it up, I
think this is working. I am able to work anything I can hear on 160m.
WRT reception, so far this season working what I hear is not saying much out
here in North West Texas. We are simply not hearing what stations a few
hundred miles in any direction are hearing. I am using both the inverted L and
a K9AY loop for receive switching back and forth for best copy and many times
using both in diversity reception mode. If it were just me I would say I have
a receiving antenna issue but other experienced 160 operators in the area are
experiencing the same thing this season. I'm baffled. Sorry to go off on a
tangent.
Very 73,
Doug, W5WTX
Amarillo, TX
Message: 1
Date: Tue, 15 Jan 2019 04:38:03 +0000 (UTC)
From: RVZ <rlvz@aol.com>
To: towertalk@contesting.com
Subject: [TowerTalk] 160m. Inverted L question
Message-ID: <369232969.276333.1547527083313@mail.yahoo.com>
Content-Type: text/plain; charset=UTF-8
Guys,
I've got a 160m. Inverted L with the vertical wire spaced 4' from a grounded
steel tower at the base and 6' at the top.? The radial system isn't perfect but
it's decent.??Based upon the Inv. L's poor performance, I believe I may have a
lot of power being coupled to the tower and shorted to ground.? A?couple
questions:
1) I'd appreciate some guestimates on what percentage of input power may be
getting shorted to ground?
2) Any guestimate on what percentage of power may be saved if the Vertical wire
spacing is increased from 4' to 12" from the tower??
Thanks & 73,
Dick- K9OM?
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