Technical research is useful but sometimes the discussion that follows
distorts the practical real world realities. Reading these threads
describing what it takes to obtain perfection, sometimes leads me to
believe
that people with less knowledge will be scared off and not try anything.
That would be a shame.
REALITY: We all should strive to make our antennas as efficient as
possible
and Rudi's work is an excellent guide, but even if you can't build
anything
remotely close to what he describes, EVERYONE with just a little bit of
real-estate can build themselves a great vertical antenna with a lot less
effort than Rudi described.
I would remind you of the THREE reasons for using a vertical antenna in
the
first place:
1. Because you have to; no space for a low band horizontal dipole
2. Because you want to improve your ability to work low band DX
3. NEW: Your sea container with all of your equipment and antennas got
lost in transit on its way to some distant island (see T32C DXpedition to
Christmas Island - www.tt2c.com ), so you organize a bunch of telescoping
fiberglass poles and some wire and build your vertical antennas on-site.
Let's focus on #2 because this would be the case where we have time and
space to apply what we've learned from Rudi.
It is fundamental to understand that a good working vertical on the low
bands is typically 2 to 3 S-Units stronger at a distance DX station than
your 40' high horizontal dipole. *** This is 12 to 18 dB improvement.***
Considering that, when someone says if I don't get it perfect, I will have
2
to 3 dB pattern distortion and 1 to 2 dB of additional loss. hey, let's
get
real. If you live in a city, every antenna you put up has pattern
distortion, and your signal will never be as good as that of someone
living
in the country with lots of space. That's no reason to just give up and
not
do anything. Just do the best you can under your own set of
circumstances:
Getting the most out of your own vertical with ground mounted radials is
pretty easy: just put down as many as you can under consideration of the
space, time and money you have available. Space them as evenly as you
can,
but if you can't, you can't.
Getting the most out of your own vertical with elevated radials takes a
little bit more work but it's not that difficult. The radials must be
resonant. Measure and string as many as you plan to use, and then with a
grid dip meter or an antenna analyzer, measure each radial and tune them
all
to resonance on the same frequency. This may be a different length for
each
radial, considering the surrounding environment. If using the analyzer,
connect the coax shield to a ground stake. Getting them resonant on the
same frequency is easy, and will get some of that 2 to 3 dB back.
GRANTED, this is not the perfect solution, but it is the best most of us
can
do and you will get a darn good performing vertical out of this; much
better
than your low-hanging horizontal dipole.
73
Rick, DJ0IP
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