Given the length and diameter of the top and bottom antenna sections, and
the LENGTH and DIAMETER of the loading coil, program LOADCOIL will calculate
coil inductance and the number of turns needed to resonate the antenna to
any required 1/4-wave frequency.


The program allows the coil to slide up and down the antenna to optimise
radiating efficiency versus physical implementation. The inductance value,
number of turns and wire gauge are automatically varied to maintain 1/4-wave
resonance versus height.


As a self-check on resonance and other results, the base feedpoint Zin is
calculated. Zin can be used in another program to calculate tuner L and C
settings. A base loading coil can be conveniently included in a tuner.


The distribution of current along the antenna, including along the coil
especially if it is a long helix, and phase relationships, are necessarily
taken into account to estimate loss and radiation resistances. But such data
is not outputted because it's of no practical use to anybody and not worth
the screen space.


The simple radiation pattern of short vertical antennas is already very well
known.


Download program LOADCOIL in a few seconds from website below and run
immediately.
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Regards from Reg, G4FGQ
For Free Radio Design Software
go to http://www.g4fgq.com
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