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

Hi Toni,

The Magnetic field near a magnetic loop is stronger than the Electric field.
A few meters away from the loop the magnetic field and electric field
produced by the antenna get more equal. The antenna is less sensitive to
pick up man made noise that is mostly produced in the electric field and
often comes from the building close to your antenna. But also noise from
industrial areas and other sources can cause trouble.

An other thing is the high selectivity of the magnetic loop. It acts as a
filter and
suppresses unwanted signals dramatically. I have quite some information and
pictures on my homepage about magnetic loops in practice and some technical
explanations about how they work.

I have several loops working here.

73, Norbert (PA7NR)
http://www.qsl.net/pa7nr/index.html