"Owen Duffy" wrote in message
...

I am working on prediction of the Antenna Factor of a small square
loop, and have created and run NEC-2 Models at a range of frequencies.
The models are documented in the draft article at
http://www.vk1od.net/SmallUntunedSquareLoop/ssulNEC.htm .

I would appreciate comments on potential pitfalls in the models that I
have created. Should I expect an antenna built to the design to
perform with perhaps tenths of a dB of the model?

Owen
--

One thing that has bothered me about small loop modeling. When
driven with a voltage source; loops of length 0.1 wavelengths
exhibit a radiated power ,and efficiency, of 0. In other words
the structure loss is than the input power. Removing
the wire conductivity loading corrects the problem. In your
particular case, at 5 MHz, the real input impedance is
more than three orders of magnitude greater than the radiation resistance.
I guess it could just be numerical rounding errors, but have gotten
identical results when using double precision.

Frank