Well, the best way to understand it is to scale it to 40 meters. The
height is important because it's effect is set by the height in
wavelength, rather than absolute height.
On 40 meters the scale equivalent would be an end-fed half wave 10
feet off the ground at it's highest point.
Lossy due to being less than 0.1 wl from ground, and a very high angle
radiator.
Making it longer at 20 ft up will not improve it much. Nor is it's
miscellaneous shape much of a problem.
What you need is some amount of high current in whatever vertical
section you can manage. Eg, straight up 40 and then out a quarter
wave. In the realm of endfed halfwaves, up 125 and out 125 would play
quite well and have that high impedance feed at ground.
On 160, lacking outstanding vertical support to hang a half wave, you
really have to deal with a high current connection to ground and put
down the best radial field you can manage.
73, Guy
----- Original Message -----
From: "Lane Zeitler" <ku7i@hotmail.com>
To: <topband@contesting.com>; <antennaware@contesting.com>
Sent: Wednesday, December 04, 2002 4:58 PM
Subject: [Antennaware] 160 end fed half wave
> Just put up an end fed half wave for 160. Unfortunately the highest
part of
> the ant is 40 ft off the ground. This occurs from the 67 to the 140
ft
> points and then from the 14o ft point it slopes toward ground, but
very
> gradual. the bitter end is abt 15 ft off of the ground.
>
> Questions:
>
> 1. What kind of performance can I expect from this thing, mainly on
160??
>
> 2. I can make it much longer, maybe even another 1/2 wave longer,
but that
> extra half wave won't be much higher than 20 ft off of the ground.
Will this
> help it on 160?
>
> 3. This thing needs a good ground screen (like a vertical)??
>
> I have noticed that it plays very well on all bands 80-10. Initial
tests on
> 160 are poor. Current ground system is a 4 ft ground rod and three
radials,
> two 20 ft long and one 45 ft long.
>
> Comments and ideas most welcome.
>
> Lane
> Ku7i
>
> PS looking down at it from the sky it looks like a symetrical L
shape.
> Wonder if this is a problem.
>
>
>
>
>
>
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