Antenna Loading Coil Calculation

The calculation method is taken from a BASIC program which I got many years ago from OA4/KA2OIG who is hereby gratefully acknowledged. (And all my responsibility is hereby disclaimed!)

Seriously, I haven't tested these designs, and would much appreciate some feedback. Please mail me.

The calculation refers to either a loaded 1/4 wave (typically a vertical, in which case flip the picture below through 90o) or a loaded dipole, in which case the dimensions refer refer to one arm and two coils will be required.

Frequency: MHz

Length of antenna or arm: Coil position, distance from feedpoint: feet.

Diameter, US wire gauge: inches diameter

Loading coil inductance micro Henries

For designing the actual loading coil go here. If you want to use a toroid go here.

This first version installed 18 May 2000.