Amen to the advice of N6KB, to build your own antenna if you have not
done one.
You should always cut the antenna elements longer than the dipole
formula by the amount needed to go around your insulators. Don't forget
there are two loops to be added, one for the center and one for the end
insulator for each 1/4 wave element. Now, add say 6 inches more to give
you some adjustable length. When you put your dipole up in the air to
test its resonance, if it is too low in frequency, fold back the six
inch extra and wrap its free end upon the standing part of the element
back toward the middle of the wires. If an antenna hits too high in
frequency, you shorten it. You can estimate how much to lengthen or
shorten, by comparing the frequency you used in the formula to the
frequency of resonance measured upon the first trial raising of the
antenna. Or, if you are in hurry, just put up the dipole and use a tuner
to correct for any mis-match to your feeder.
-Stuart
K5KVH
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