--------- Begin forwarded message ----------
From: N4KG
To: K7SX@worldnet.att.net
Subject: Re: [TowerTalk] tower height
To: <towertalk@contesting.com>
Date: Sun, 27 Apr 1997 08:57:36 PST
Message-ID: <19970427.085900.9990.5.N4KG@juno.com>
References: <19970427130935.AAA22289@davida.utw.com>
This is the age old antenna question!
There is NO SINGLE OPTIMUM HEIGHT, especially for the high bands. TWO
antennas at 40 and 80 ft are very effective with
switching for upper, lower, and both in phase.
For daytime conditions, especially to Europe and Africa, my 40 ft
high antennas often outperform my higher and bigger antennas. To
the Caribbean (which is very close to W4) my high antennas often
outperfom my lower antennas, especially in the late afternoon as the
MUF drops and it becomes a single hop mode of less than 10 degrees.
Much computer generated data has been compiled in an attempt to
"PROVE" than higher is "always" better, but these studies make
several assumptions which are not always correct and the authors
seem to be blind to the considerable contradictory evidence and
observations that has been published from numerous observers.
Bottom line: You can never have enough antennas!
Propagation depends on too many factors for there to be only one
optimum height (wave angle) for even one band, much less three.
For example, I find it implausible to even consider that there would
be only one optimum wave angle on 20M when the MUF can vary
from 15 MHz to 42 MHz. On the higher bands, there must be
hundreds of reports of lower antennas beating high antennas during
daytime operation.
IMHO, everybody should have a tribander or equivalent at 40 ft. over
flat ground. Add higher antennas as space and budget permit.
de Tom N4KG
.
On Sun, 27 Apr 1997 07:10:29 -0600 "David McPhie" <K7SX@worldnet.att.net>
writes:
>What is considered optimum height above ground for a tribander? I
>know it
>is affected by surrounding terrain, but assuming flat level
>surroundings,
>and that the antenna will see the ground as ground, and not some
>rooftop,
>whats the best height?
>
> Is there any consensus on this, Ive heard 80 ft , 105
>ft, and just plain
>the higher the better.
>
> It seems to me that there must be sone "node" height that has
>demonstrated itself as beeing the most desireable within practicle
>limits.
>
>
>Dave McPhie K7SX [doing alright with a 50 ft tower, but always
>dreaming]
>
>--
>FAQ on WWW: http://www.contesting.com/towertalkfaq.html
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>
--------- End forwarded message ----------
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