Randall J wrote:

OK Gary, guess I'm a little dense on the subject but the EZNEC software
is a bit complex for me. Can't seem to figure out the Reactance of my
8ft x 1/2inch aluminum antenna. I did find that the "SRC Dat" gave an
impedance of 0.2714 - J 9981 ohms. How do I find the reactance?

I do have the 1988 version of the ARRL handbook and have found the
formula for finding the inductance which in turn can be solved for "n",
the number of turns.

Randall

The reactance is the "J" part, and negative means capacitive. So at the
source, the impedance is 0.2714 ohms of resistance in series with 9981
ohms of capacitive reactance. You'll need 9981 ohms of inductive
reactance to cancel it out. That would mean an inductance of
9981/(2*pi*f), which would be 1.59 mH at 1 MHz for example.

If your inductor has a Q of 200 (which might be hard to do for that
large an inductance), its loss resistance will be 9981/200 = 50 ohms. My
guess is that your ground system will also have a resistance of about
that, unless you put in quite a few fairly lengthy radials, giving you
an overall feedpoint resistance of about 100 ohms. The efficiency would
then be 0.2714/100 = 0.27%.

Roy Lewallen, W7EL