[TowerTalk] Horizontal + Vertical Polarization Question

[Gene Smar]

TT:

     I have seen similar performace differences on Topband between my
shunt-fed tower with seven radials and my erstwhile 160M inverted L with a
half-mile of radials (!) and the vertical element 45 feet long.  My tower
hears and talks about 5-10 dB better than the L ever did.  (Although an L is
certainly a cheaper alternative than putting up a tower, Hi Hi.)

     FWIW.

73 de
Gene Smar  AD3F

----- Original Message ----- 
From: "Richard Karlquist" <richard at karlquist.com>
To: <towertalk at contesting.com>
Sent: Sunday, November 23, 2003 11:45 AM
Subject: RE: [TowerTalk] Horizontal + Vertical Polarization Question


> 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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>
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