Jerry,

I ran EZNEC on this, using the QST dimensions, and got what seem to be
reasonable results.

Resonant frequency = ~7.11 MHz
Impedance = 21.15 + j1.17

For those who obviously did not read the QST article, the 25 uH loading
coils are 1.7 meters from the ends. Total length is 10.64 meters, and height
is 6 meters. Over real ground, maximum gain is about 6dbi, straight up, and
about 3 dbi at 30 degrees elevation.

Tam/WB2TT
"Jerry" wrote in message ...
October's QST has an article "Designing a Shortened Antenna" pp 28-32. It
gives an example of a shortened dipole for 40 meters at 7007 khz. Dipole
length of the half-sized dipole [p30 "a second example"] is 10.61 meters.
This is 20 feet off ground using #12 wire. The formulas give a solution
of
XL= +j1776 ohms or an inductance of 40 microhenries at 30 degrees from
each
leg.


I tried to simulate this antenna on EZNEC. A 10.61 meter antenna at 7007
khz
gives impedance =11.33 - j 881.2 ohms.

If EZNEC is correct wouldn t I need an inductance of +j881.2 on each leg
of
the dipole, rather than +j1776?

--
Jerry