[Amps] Voltage at feed point

[Paul Christensen]

> Anyone know a formula for calculating the voltage at the feed point of a
> vertical if you know the resistive and reactive values and the power?
> Example:  160 meter inverted L, R = 80 ohms, X = +420j & P = 1500
> watts.  73, Rob, NC0B.

The resulting Z is 428-ohm.  At 1500 watts, I calculate 800 volts at the 
base.

I first solved for Z by taking the overall square root of the R-square + 
X-square value.  I then solved for E through P = E-square x Z.

Correct?

Paul, W9AC