Topband: Impedance of two wires to ground?

[Rick Karlquist]

Michael James wrote:
> Hello,
>
> I'm looking for the formula to calculate the surge impedance of two wires
> parallel to the ground, given the diameter of the wires, the wire spacing,
> and height above ground.
> Mike W0BTU

See page 197 of:

http://www.pmillett.com/Books/FTR_ref_data.pdf

The first formula is for common mode and the second
is for differential mode.

Rick N6RK