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Tune Around! Topics For
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Using CB Antennas
on the 10 Meter Ham Band
By N4UJW
When the band is "open" it does not take loads of power,
multielement arrays or lots of skill to make contacts to
distant lands and fellow hams around the world.
In making "DX" contacts, (contacts out of your country),
you will want your signal to reach out as far as possible at a low angle
to the earth's horizon and not go out at a high angle relative to the
earth.
The lower
the angle of radiation, the further your signal will go bouncing further
and further around the globe using the ionosphere as your "reflector" in
space.
Having an antenna that has a low angle of radiation on 10
meters is of great importance in getting those DX stations to
hear a stronger signal from you. Using low angle radiation type vertical
antennas also greatly improves your chances over your "local" area also.
Many operators use 10 meter mobile rigs in their vehicles with of course
vertical antennas mounted on them, so in order for you to communicate with
them at any distance, your antenna must be the same
polarizaton...vertical.
So what
types of antennas have a low angle of radiation that will reach those
local operators AND DX stations with the same antenna you may
ask?
Enter the vertically polarized antenna.
There are
many ways to utilize a vertical antenna on the 10 meter band from
simple homebrew wire verticals hung in a tree to commercially built
high dollar multielement beam antennas designed for this
purpose.
Use a CB antenna on 10 meters!
One of the
simpler ways of getting a really good low angle signal out at much less
expense is to use a vertical CB antenna converted to 10 meters. Yes, you
read that correctly....a CB antenna.
Many of the
commercially made CB antennas can be easily converted to 10 meter use by
just a simple tuning modification of the CB antenna length. Since
they were originally designed for 11 meter use on the CB band, they are
usually longer than those required for the 10 meter ham band due to
the difference in frequencies.
So by using
an old CB antenna OR a new one that may be very inexpensive, you can
modify it by shortening it until you get the lowest swr on your favorite
band, 10 meters.
There are
several brands and models of commercially made vertical CB
antennas that have been designed to cover many of the ham bands
"outside" of their original design parameters of the
CB band.
So what would be a good commercial CB antenna to use on 10 meters? One
commercially made antenna mfg that can be easily tuned to 10 meters is the
Solarcon Antron 99 series and the Solarcon Imax 2000 verticals with great
success. These particular verticals come with a tuning adjustment that
will enable them to be used even down to 20 meters with a tuner. They get
very highly rated reviews and are very popular among 10 meter operators
and have been used for many years. They work well without a tuner when
used on 10 meters due to their wide frequency range
design.
The
adjustment to take them "up" to 10 meters is a simple matter of a
shortening of the vertical element and a fine tuning of a "tuning"
ring adjustment for lowest swr.
The Antron
A-99 antenna is a 17 foot tall antenna as designed and the Imax 2000 is 24
feet tall when it comes from the factory.
Either of
these antenna can be readily used on 10 meters with just a bit of
simple tuning and you will be very pleased at their performance. They get
great reviews and are widely used.
The A-99 is
the least expensive of the 2 models at around $60.00, 2011
prices, and the Imax 2000 is usually under $100.00. Both are
fiberglass and will handle more than the legal limit of rf
power.
So
bottom line, if you don't want to build your 10 meter antenna or convert
that old CB antenna you may have laying around, then these antennas are
highly recommended and highly rated for the 10 meter operator who
wants to get more signal out to the horizon for those DX
contacts. From John,
KL7JR: 73, just my two cents worth! KL7JR Check them out below!
If you don't want to lay out
the money for a commercially made CB antenna
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