Frank wrote:
....
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.


I have modified my EZNEC model to irrradiate the loop from an exciter
dipole at some distance. I have tried it with the exciter at 100m and
200m distance, I get AF=35.69 and 35.72 dB respectively (against 36.1
from the Mathcad model). I note that if you report on the so called near
field values too close to the loop, the results are effected by the loop.

I note that the Matchcad model estimates the inductance slightly higher
than EzNEC, and others have suggested to me that the Lw term in the
Matchcad model is a double up, that the Ll term fully accounts for the
inductance of the loop. Removal of the Lw term results in an AF of
35.8dB, which is closer to the EzNEC prediction.

Has anyone views of whether Lw should not be included?

The currents in my model vary slightly, here is the current report:

Frequency = 7.1 MHz

Wire No. 1:
Segment Conn Magnitude (A.) Phase (Deg.)
1 W4E2 4.0E-6 -137.0
2 4.0E-6 -137.7
3 4.0E-6 -138.1
4 4.0E-6 -138.4
5 4.0E-6 -138.5
6 4.0E-6 -138.4
7 4.0E-6 -138.1
8 4.0E-6 -137.5
9 W2E1 4.0E-6 -136.8

Wire No. 2:
Segment Conn Magnitude (A.) Phase (Deg.)
1 W1E2 4.1E-6 -136.0
2 4.1E-6 -135.1
3 4.1E-6 -134.2
4 4.1E-6 -133.4
5 4.2E-6 -132.5
6 4.2E-6 -131.7
7 4.2E-6 -130.8
8 4.3E-6 -130.0
9 W3E1 4.3E-6 -129.2

Wire No. 3:
Segment Conn Magnitude (A.) Phase (Deg.)
1 W2E2 4.3E-6 -128.4
2 4.3E-6 -127.8
3 4.4E-6 -127.4
4 4.4E-6 -127.2
5 4.4E-6 -127.1
6 4.4E-6 -127.2
7 4.4E-6 -127.4
8 4.3E-6 -127.9
9 W4E1 4.3E-6 -128.5

Wire No. 4:
Segment Conn Magnitude (A.) Phase (Deg.)
1 W3E2 4.3E-6 -129.3
2 4.3E-6 -130.1
3 4.2E-6 -130.9
4 4.2E-6 -131.8
5 4.2E-6 -132.6
6 4.1E-6 -133.5
7 4.1E-6 -134.3
8 4.1E-6 -135.2
9 W1E1 4.1E-6 -136.1



Owen