"Roy Lewallen" wrote

Very close to a small loop antenna, response is greater to an H field than
E field. It does respond to both, however, as all antennas must. As you
get farther away from the antenna, the response to the H field decreases
in relation to the E field response. At around an eighth wavelength
distance from the antenna, the response to E and H fields are about the
same as for a distant source. Beyond about an eighth wavelength, the
response to the H field is actually *less* than the response to an E field
compared to a source at a great distance. The ratio of E to H field
responses then decreases to the distant value as you get farther from the
antenna.

In summary, the antenna responds more strongly to the H field if the
source is within about an eighth of a wavelength from the antenna. Beyond
that, it actually responds more strongly to the E field relative to the H
field than a short dipole or many other antennas -- you could more
properly call it an "E-field antenna" in its response to signals beyond
about an eighth wavelength. The difference in relative E and H field
response among all antennas becomes negligible at great distances; for
antennas which are small in terms of wavelength, the difference becomes
negligible beyond about a wavelength.


But according to W8JI "teachings" there is no way that electrostatic shield
on a small loop antenna would work as a shield, attenuating E field dominant
signals or noise generated within that 1/8 or about wavelength.
According to him, it works as an antenna. Some scientwists can not
comprehend that electrostatic shield shunts the predominantly E field
generated in the vicinity. It is the FACT, easily observable by anyone
building shielded small loop and having TV birdies, PS bricks or arcing
noise source within about 1/8 of a wavelength.

W8JI wrote:
Seriously, precipitation static is caused by corna discharge from an
antenna or object someplace near the antenna. The radiated field from
that leakage current can be almost any field impedance and will always
be a mixture of time-varying electric and magnetic fields.

Roy, 'splain to him about this 1/8 or so thing. He still dungetit.

73 Yuri, K3BU

Yuri Blanarovich wrote:
. . .
Roy, 'splain to him about this 1/8 or so thing. He still dungetit.

Tom understands it, but I see you don't quite have a handle on it yet.

Roy Lewallen, W7EL

"Roy Lewallen" wrote in message
...
Yuri Blanarovich wrote:
. . .
Roy, 'splain to him about this 1/8 or so thing. He still dungetit.

Tom understands it, but I see you don't quite have a handle on it yet.

Roy Lewallen, W7EL

So I "don't get it" because I (and others) see the difference in reality,
when electrostatic shield suppresses the local interference. You explain
behavior of E and H field in the vicinity of antenna but that does not apply
to "W8JI shield is the antenna" and "current at both ends of the loading
coil is always the same".

I will stick to my reality handle, rather than joining scientwist's chorus.

73 Yuri, K3BU

My reality, and Tom's, fits with the clear explanations in Johnson's
_Antenna Engineering Handbook_ (successor to Jasik); King and Harrison's
_Antennas and Waves_; King, Mimno, and Wing's _Transmission Lines,
Antennas, and Wave Guides_; and undoubtedly others, since it comes from
basic electromagnetic principles.

I explained the nature of the E and H fields from a small loop antenna.
This is the sum of the fields from each part of the loop. It is not
representative of the field in the small region between the wire and
shield of a "shielded" loop, as you seem to be trying to infer.

If you'd spend a fraction of the time studying that you spend
desperately trying to find something wrong with anything Tom says, you'd
have a much better understanding of how antennas work.

Roy Lewallen, W7EL

Yuri Blanarovich wrote:
"Roy Lewallen" wrote in message
...
Yuri Blanarovich wrote:
. . .
Roy, 'splain to him about this 1/8 or so thing. He still dungetit.
Tom understands it, but I see you don't quite have a handle on it yet.

Roy Lewallen, W7EL

So I "don't get it" because I (and others) see the difference in reality,
when electrostatic shield suppresses the local interference. You explain
behavior of E and H field in the vicinity of antenna but that does not apply
to "W8JI shield is the antenna" and "current at both ends of the loading
coil is always the same".

I will stick to my reality handle, rather than joining scientwist's chorus.

73 Yuri, K3BU

"Roy Lewallen" wrote

If you'd spend a fraction of the time studying that you spend desperately
trying to find something wrong with anything Tom says, you'd have a much
better understanding of how antennas work.

Roy Lewallen, W7EL



Congratulations Roy,
you have nove graduated from "W8JI school of personal mud slinging" when
running out of arguments.
How perceptive: " ...desperately....anything Tom says...."

"Better understanding" - you mean swallowing fallacies you scientwists
proclaim?
I will stick with my understanding of how antennas work and I can measure,
vs. your misapplied theories why it "can't be so".

73 Yuri, K3BU

The only useful purpose served by making a loop antenna from coaxial
cable is to ensure capacitance balance of the loop against ground, so
sharpening its directional nulls and, incidentally of course, to
support the very thin inner conductor which would otherwise collapse
under its own weight.

The outer coaxial conductor has no effect on signal to noise ratio as
perceived by the receiver. S/N ratio depends only on what's contained
in the local field itself.

If there's any difference in S/N ratio due to use of a tuned loop, as
with a magloop, then it is due to the loop's very narrow bandwidth -
not the shield.
----
Reg.