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RE: [TowerTalk] Horizontal + Vertical Polarization Question

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Subject: RE: [TowerTalk] Horizontal + Vertical Polarization Question
From: "Richard Karlquist" <>
Date: Sun, 23 Nov 2003 08:45:07 -0800
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This experimental data may be of interest:

Friday night I did a bunch of A/B tests between
an 80 meter inverted vee, 120 degrees apex
angle, 60 feet apex height versus a voltage
fed vertical.  The vertical is actually my
top loaded 90 ft 160 meter vertical, which
is resonant at 1.830 as a voltage fed antenna,
and resonant at the second overtone as a 
current fed antenna.  It is over a big ground
screen.  The two antennas are separated by 
800 ft, so there is no interaction.  The vertical
has an insulated base and is fed through a series
180 pf capacitor with a shunt inductor around 10
uH from the vertical to ground.

The results were immediately obvious.  Almost
all stations were 5 to 10 dB stronger (on a 
calibrated S meter) on the vertical.  Only
very local stations were stronger on the 
inverted vee, and in that case up to 20 dB
stronger.  A true cloud warmer.  The crossover
point seemed to be about 300 miles.  Several
station in Las Vegas were equal strength on
both antennas (including an Art Bell sighting :-)
I made a dozen or so QSO's and everyone commented
on how well the vertical was getting out.

Thus in this case, it probably doesn't make any
sense to combine the antennas, except in Sweepstakes
where I wouldn't want to miss the many SF Bay area
stations that are 50 to 100 miles away.

I am fairly sure the low height is the problem for
the vee.  A rotatable dipole at 90 to 120 feet would
probably start to compete with the vertical.  It I
had that kind of antenna available, then I could 
revisit the polarization question.

Rick N6RK


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