Hello Richard,

I agree with you that several statements on Norbert's site will not
hold when scientifically reviewed. However I think the way you
respond will likely not result in better statements.

As the name of the newsgroup indicates; this is a radio amateur group
and Norbert site starts with "Dutch amateur radio station". This may
require another approach then you should use in a professional
environment. If you prefer that, Edaboard.com (just an example) is a
more suitable place.

Now the result is a professional reaction of Norbert:

Thank you for the explanations. I have not had the intention to start a
scientific discussion here on this subject. To me it is a hobby. With my
homepage I just want to share some of my experience with magnetic loop
antennas, just like many other radio amateurs do. And of course I am willing
to reply to reactions from readers. But I will not further discuss about
scientifically details.

Thank you.

Best Regards

73,

Norbert PA7NR

Because of rain, I had to stop some activity so I took a pocket
calculator, some of my own course material and a used envelope within
reach.

A loop with diameter = 1.27m (4m perimeter), made from 20mm (diameter)
copper has an inductance of about 3.4 uH (reactance of about 77 Ohm at
3.6 MHz).

Radiation resistance (no coupling with other objects) will be about 1
mOhm.

AC copper resistance due to skin effect will be about 30 mOhm (based
on uniform current distribution over the circumference of the
tubing).

Q factor should be in the range of 2500
Radiation efficiency will be about 3%
Directivity is 1.5
Voltage between ends (100W input): 6.3 kVp.
Current through loop about 82 Ap

A half wave dipole will have about 1kVp at each end (depends on
conductor thickness).

Effective area of antenna will be about 23 sqm (in free space).

1Vrms incident plane wave field (2.65mW/sqm) will result in about 61mW
output power (about 150Vp across the tuning capacitor).

You probably know that measuring a lower Q factor may result in less
overall efficiency (coupling to dissipative objects) or higher overall
efficiency (coupling to metallic conductors that reradiate).

With kind regards,


Wim
PA3DJS
www.tetech.nl
without abc, PM will reach me very likely