Topband: Inverted L Question

[Guy Olinger K2AV]

Hi, Lloyd,

Using an L with the vertical running next to a tower like that means that
your tower is FULLY coupled to the L as if they were both transformer
windings.  The principal determination of performance in this situation is
the tower, not the L.  You will find that all conductors on the tower are
fully induced.  For all practical purposes, the L is just another way to
load a tower.

This is very easy to model.  In quite a few situations, there will actually
be more current in the tower than in the L, particularly for shorter towers.

My collection of stories about running L's next to towers, alas, mostly has
poor outcomes.

My personal advice on L's includes "Never use a tower to support the
vertical rise of an inverted L --  there are better ways to load a tower."

There ARE ways to make the L work.  Problem is that most people don't want
to ground and bypass tower conductors and run radials, etc, and by the time
you've done that, the tower is perfectly prepared to load the tower itself
and the L is not needed for anything.

73, Guy.

On Fri, Apr 27, 2012 at 9:07 PM, Lloyd Korb <k8dio at roadrunner.com> wrote:

> Hello, I have used an Inverted L, on 160 meters, for many years and have
> always been curious if I am okay with my present spacing.  The spacing
> between the vertical portion of the L and my 60 foot tower is 18 inches.
> The spacing was picked for the ease of feeding the wire at the base of my
> tower.  The horizontal part, of the L, is around 85 feet and goes from the
> top of the tower to a pole that is 6 feet above the ground.  Does anyone
> know of any studies done on the performance of the L versus the spacing of
> the vertical wire to the tower?
>
>
>
> I'm also wondering if I could run another wire, on the opposite side of the
> tower, for an L on 80 meters.  It would be nice to be able to have two
> bands
> available.  Will there be any interaction between the two wires?  My
> present
> radial system is 24 wires of various lengths to fit in my yard.
>
>
>
> 73,
>
>
>
> Lloyd  K8DIO
>
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