In a free-space field far from any antennas, the ratio of electrical
to magnetic fields, for time-varying fields, is always the same, so in
such a field, just as you say, there is no way to separate "man-made
noise" from something that we hope might have more information than
the noise in it. (But avoid American telecasts when making this
comparison...)

However, near the source of the man-made noise, the ratio is likely to
be much higher (more electric than magnetic), and it's in that
near-field area where the loop may do you some good. That tends to
mean that the rejection will be best at low frequencies, typically
medium-wave (AM domestic broadcast band) and lower. In general, in
the near field of any antenna, you will see E/M ratios that are
significantly different from the far-field ratio.

To take advantage of the possible man-made noise rejection, the
receiving loop must be properly designed and constructed, and of
course the noise must indeed be maily electric-field at your location.

Cheers,
Tom

Toni wrote in message . ..
Hi,

I have always been taught that electrical and magnetic RF fields
went always together. You couldn't produce one without the other
and vice-versa.

Then I read about mag-loops having better RX noise immunity than
normal antennas because they react to magnetic fields, whilst
man-made noise occurs mostly on electrical fields.

??????

If both fields go together, how can noise be greater in the
electrical field than in the magnetic one? Does that mean that
you can effectively produce one without the other?

Taking it further, if you can _receive_ one while rejecting the
other, then, by the reciprocity law, you should be able to
produce one without the other.

What is (where am I) wrong?

EA3FYA - Toni