Topband: beverage lobes
w8ji at contesting.com
Tue Jan 9 14:45:04 EST 2007
> When observers are making judgments on arrival angles, are
> they basing their judgments on which of several different
> types of antennas with different TOAs produces the loudest
> received signal?
I only do that on transmitting antennas, and I never base my
opinions on a single weekend once a year during a contest.
With station after station coming at you that just isn't the
place to form accurate opinions.
So far as transmitting antennas, nearly 100% of the time my
~200 foot omni vertical with 100 200-foot radials beats a
dipole at 300 feet. It was this way in 1970 in Ohio, in 2000
and 2001 here in GA, and it is that way at the solar
minimum. These are all blind A-B tests, the person giving
the report has no idea what antenna I am using. This leads
me to believe the wave angle is pretty low, or any path in
any direction from here (or Ohio) favors a vertical. By the
way a dipole at 130 feet is often insignificantly behind the
high dipole, and a 1/4 wl vertical with 50 radials is
insignificantly behind my 200 foot vertical. The primary
exceptions are during geomagnetic storms or right at
So far as receiving, I only consider readability of the
weakest signals. Nothing else. All of my antennas are gain
equalized so they all have about the same nighttime noise
floor. Since I normally receive in stereo with matched
receivers and can pick any antenna on any ear it is easy to
get a feel for the best overall copy. I care less if someone
already 20 dB out of the noise is 10 dB weaker or stronger.
All of my nighttime noise is propagated noise. The
propagated noise is typically ten dB or more greater than
local daytime noise, so local noise is not a factor at my
I really don't know how we would measure arrival angle on
160 without an interferometer setup for nulling signals.
Quite often there is considerable multipath or multi-angle
propagation, I do know that from actual measurements.
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