I have done some more calculations on a square loop fed at the corner. I
agree with your results of input impedance. NEC 2 shows Zin at 0.388 +
j109. The radiation efficiency of such a loop is 2.88%. I have made a
very careful analysis of the currents in the loop when in the presence of
a know E field. The current appears to vary in a sinusoidal manner around
the loop, with very slight discontinuities at the corners. I assume the
variation in current is due to the fact that the induced current is
different on those conductors normal to the dipole axis.

Using the RMS current through the 50 ohm load resistor at the corner, and
more careful calculations, I obtain an antenna factor of 60 dB, or 24 dB
more than your findings. It will be interesting to find why we have such
a large difference.

I see nobody picked up my deliberate mistake! Using Terman's simplified
formulas on pp 813, and 814, I get identical parameters of induced voltage,
and antenna factor. I completely agree with the results of the Mathcad
file, although have not gone through the more intricate equation development
yet.

Using NEC 2 I found out, the hard way, that maximum pick-up takes place off
the ends of the loop. Given these constraints: With a field strength of
5.5 V/m, the voltage across the 50 Ohm resistor is 0.091 V RMS, or an
antenna factor of 35.1 dB. Within 0.4 dB of Owen's results.

Interesting exercise, and I actually learned something.

73,

Frank