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Re: [TowerTalk] Actual LP Performance vs Tribanders

To: "w3frg" <>, <>,"Pete Smith" <>
Subject: Re: [TowerTalk] Actual LP Performance vs Tribanders
From: "Tom Rauch" <>
Reply-to: Tom Rauch <>
Date: Fri, 25 Jun 2004 23:06:13 -0400
List-post: <>
> But let's ask a practical question.  If you are trying to
evaluate a
> horizontally polarized antenna, either versus another or
more generally,
> won't the relative signal to a station a mile or two away.
as you rotate
> the antenna, give you some indication?

Ground effects are attenuating or nulling ANY horizontal
signal following the earth. The worse possible way to
measure anything is in the null, because small changes in
the system which includes everything between and around the
antennas can cause big changes in FS.

The slightest amount of feedline radiation or polarization
tilt of a horizontal wave caused by reflections from other
structures can cause huge changes in FS over groundwave,
because path attenuation is significantly less for vertical
polarization at HF frequencies and lower.

With that in mind, what would a groundwave measurement tell

This is exactly what mislead a certain fellow into thinking
his stub-matched all band dipole was several S-units louder
than a tuner matched but otherwise *identical* dipole. Poor
measurement methods are at the root of much misinformation
we see. Measuring a horizontally polarized antenna over a
large distance (more than a few wavelengths) is definitely a
very poor method.

It would be much more reliable to measure skywave in an A/B
test than groundwave of a horizontal antenna.

73 Tom


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