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Re: Topband: low inv-vee

To: topband@contesting.com
Subject: Re: Topband: low inv-vee
From: K4SAV <RadioXX@charter.net>
Date: Thu, 29 Mar 2018 09:11:36 -0500
List-post: <mailto:topband@contesting.com>
If you run a NEC analysis it will show that a 160 dipole at a half wavelength height will blow away any vertical when the signal is broadside to the dipole. The people that have tried this say it aint so. At least some of the reasons are that NEC knows nothing about 160 propagation and it knows nothing about the effect of Earth's electron gyrofrequency. That varies a lot depending on where you are located on this earth. Analysis is nice and easy but you have to include everything for it to simulate the real world, and the real world on 160 is very complicated.

Jerry, K4SAV


On 3/28/2018 9:50 PM, Mark K3MSB wrote:
I don't think so.  In my Electromagnetic Fields and Waves class in EE
school (way back when dinosaurs just stopped roaming the earth and
Constellations still graced the skies...) the prof derived the equation for
a received signal.  The polarization terms disappeared after the first
ionospheric bounce.

73 Mark K3MSB


On Wed, Mar 28, 2018, 9:03 PM Steve Maki <lists@oakcom.org> wrote:

Interesting. Some say that on 160 vertical polarization rules, while on
80, horizontal polarization rules (or at least *often* rules). Of course
polarization and angle of arrival are two different things...

-Steve K8LX

On 03/28/18 17:23 PM, Roger Kennedy wrote:

Well I've said it before and I'll doubtless say it again . . .

In my experience, most DX propagation on 160m ISN'T low angle  (unlike
80m
when it nearly always IS.)

For the past 45 years, at several different QTHs I've always used a
horizontal co-ax fed halfwave dipole, only 50ft high . . . I'm sure most
people would agree I put a respectable DX signal.  I've regularly worked
all
over the world on Top band, and I've never had trouble getting through
pile-ups to work Dx-peditions.

Plus a dipole at 40 feet will never really be an inverted vee ! (just a
horizontal antenna with drooping ends) - You'd have to have the centre at
least 100ft high for it to be an inverted vee.

Roger G3YRO
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