Topband: Inverted L question

[Guy Olinger K2AV]

The most important part of an inverted L is the counterpoise, be it raised
radials, buried or on-ground radials or an FCP. Be sure you can do a
counterpoise well. Otherwise the counterpoise can be a huge RF loss, easily
negating anything done well with the L wire itself.

Next the vertical part of the wire is most important. 80 feet up will do
very well, and will carry the large majority of total RF current density.

The horizontal will fill in the hole in the doughnut pattern of a vertical,
but more useful, you can use its length to help tune the antenna. Adding or
taking away from the far end of the horizontal can be a very useful tuning
device. The shape, slope, "straightness" of the "horizontal" are fairly
immaterial. Dropping down at 45 degrees will produce a lower feed Z and a
narrower bandwidth than the same pulled away parallel to the ground.

The pattern of an L always has a mild to moderate weakness in the otherwise
omnidirectional pattern, in the direction that the horizontal pulls away
from the bend in the L. In the Southeast US, you want the horizontal wire
of an L to pull away toward the SE, so the weak quadrant is not to the SW,
W, NW, N or NE.

73, Guy K2AV

On Tue, Feb 3, 2015 at 4:55 PM, Art Snapper <art at nk8x.net> wrote:

> I have been looking at locations on my property to install an Inverted L
> for 160.
>
> How important is it for the top part to be led away at a right angle?
>
> I was considering running it vertically 80ft, then about 25 feet at a 45
> degree up angle and 25 feet at a 45 degree down angle, over the top of the
> supporting tree.
>
> de Art NK8X
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