Is there a web site where I can read about the relation between the
thickness of the wire and the bandwith.
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Antenna bandwidth changes very slowly relative to wire diameter. It is best
considered in terms of antenna Q at 1/2-wave or 1/4-wave resonance.

Approximately -

Q = 1.7 * [ Ln( Lambda / 2 / Diameter ) - 1]

where Lambda is free-space wavelength and conductor diameter is in the same
units. Ln is the logarithm to the base e.

The formula applies up the point where conductor diameter is about 1/6 of
dipole antenna length.

Knowledge of antenna bandwidth is not of great practical use at HF because
the Q of the feedline plus tuner has at least the same effect on the overall
system bandwidth as the antenna.

Download program DIPCAGE2 from website below to see how bandwidth changes
with effective diameter of a dipole cage antenna.
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Regards from Reg, G4FGQ
For Free Radio Design Software go to
http://www.btinternet.com/~g4fgq.regp
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