Alternative Antenna Loading Coil Calculation - Imperial/US Units

The calculation method is taken from an article by Luiz, CT1EOJ, October 2003 QST. The method is different from that used in my original calculator.

An assumption of the calculation is that the antenna corresponds to a single horizontal transmission line whose characteristic impedence is approximated by:

Z0 = 138 log10 (4h/d)

Where h/d is the ratio of antenna electrical height to wire diameter. This is obviously not correct for a vertical whip.

I have also written a metric units version.

Frequency: MHz

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

Diameter, US wire gauge: inches diameter.

Antenna height feet.

Loading coil inductance micro Henries

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

This version installed 19 September 2010.