Dave.
A vertical is omni in azimuth, while a dipole has some directivity. This, the
dipole has more gain in the favored direction, even in free space. This is
normal.
73,
Drew K3PA
------------------------------
Message: 2
Date: Mon, 15 Mar 2021 11:26:00 -0400
From: Dave Sublette <k4to.dave@gmail.com>
To: kj6y--- via TowerTalk <towertalk@contesting.com>
Subject: [TowerTalk] Vertical question
Message-ID:
<CAKynJKn0WE5EvR27LMMhnTgueTJh5A=97dR1tW2rzS1-GeXiLQ@mail.gmail.com>
Content-Type: text/plain; charset="UTF-8"
Good morning,
I recently changed my elevated 160 meter quarter wave vertical with 8 full
sized radials to having only 1/8th wave length radials and only four of them.
It is working great. So I thought adding four more radials might improve
things.
But before I went to all the trouble I decided to model it and see if there was
a difference in performance of the 8 radial version compared to the 4 radial
system.
I use a modelling program called Antenna Model. The result of the comparison
is this:
The 4 radial system showed a gain of 0.92 dBi with the main lobe at an
elevation of 20 degrees.
The 8 radial system showed a gain of 0.93 dBi and an identical elevation
pattern.
My question is: Why is the gain figure so low? A dipole exhibits 2.14 dBi
gain. Why doesn't the vertical show gain?
And lastly, I think these results tell me it isn't worth the effort to add four
more radials.
Your thoughts?
Thanks & 73,
Dave, K4TO
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