The RFI field from the average home extend much less then I had
thought. <<<<
Hi Will,
I'm not sure how much you were thinking it extended, but here I use a
figure of about 20 feet to be on the safe side. I measured the noise
(actually, noted it) out to about 15 feet while walking around with a
portable radio. I have also tried to catalog and describe each noise for
each appliance or device because there were so many before I switched to
an outside loop and I wanted to know which plug to pull when necessary.
Dave
--- In loopantennas@..., "gfreport1" <gfreport@...> wrote:
--- In loopantennas@..., Ken Javor <ken.javor@> wrote:
But that discussion misses the point that the high impedance rfi you
are
avoiding with a shielded loop comes from nearby, in the near field,
while
the signal you are receiving is from far away. If the problem is two
intentional signals from far away, then the discussion is correct
and you
rely on frequency discrimination (tuned loop and/or tuned front-end)
to
discriminate between two closely spaced but different frequency
signals.
Finally, there is a very real value to shielding against the
electric field
of the very signal you are trying to receive - when you are
interested in
direction finding. The direction finding property of the loop is
related to
the magnetic, not electric field you are receiving.
Take a look at Dallas Lankford's measurements on "Measurements of
Some Antennas Signal to Man Made Noise Ratios" at:
<
Measurements%20Of%20Some%20Antennas%20Signal%20To%20Man%20Made%20Noise%20Ratios%20II.pdf>
The RFI field from the average home extend much less then I had thought.
Will
