Yuri Blanarovich wrote:

"K7ITM" wrote:
It seems to me that when "W8JI" is associated with something, you
assume immediately that it is wrong.

That's what might seem to you, but I point out gross misinformation, when I
come across it.

What gets missed quite often in these discussions is that
everyone agrees on 99 44/100 percent of the technical issues
and we tend not to discuss those issues. We only discuss the
56/100 percent of the issues upon which we disagree. It is
akin to the arguments between Einstein and Bohr. I suspect
that no two people here on r.r.a.a are in 100% agreement
on everything.
--
73, Cecil http://www.qsl.net/w5dxp

Cecil Moore wrote:
Yuri Blanarovich wrote:

"K7ITM" wrote:
It seems to me that when "W8JI" is associated with something, you
assume immediately that it is wrong.

That's what might seem to you, but I point out gross misinformation, when I
come across it.

What gets missed quite often in these discussions is that
everyone agrees on 99 44/100 percent of the technical issues
and we tend not to discuss those issues. We only discuss the
56/100 percent of the issues upon which we disagree.

Make no mistake about it, I disagree with everything Yuri has posted
about the physics behind a "shielded loop".

I certainly don't want to be considered to be 99% in agreement with
anyone who thinks a time-varying magnetic field can pass though a
highly conductive copper wall, or any wall that is several skin depths
thick, just as I don't want to be 99% in agreement with anyone who
thinks a loading coil "replaces" or has the phase shift or "current
drop" of missing electrical degrees.

The basic physical properties have to be understood before I'd be
largely in agreement. If basic building blocks are wrong, our idea of
how the worlds works must also be very distorted.

73 Tom

wrote:
Cecil Moore wrote:
What gets missed quite often in these discussions is that
everyone agrees on 99 44/100 percent of the technical issues
and we tend not to discuss those issues. We only discuss the
56/100 percent of the issues upon which we disagree.

Make no mistake about it, I disagree with everything Yuri has posted
about the physics behind a "shielded loop".

That's part of the 56/100 percent of the issues upon which you
disagree.

... I don't want to be 99% in agreement with anyone who
thinks a loading coil "replaces" or has the phase shift or "current
drop" of missing electrical degrees.

Just proves that no individual is right 100% of the time. 75m
bugcatcher coils obey the laws of physics and thus suffer a
delay in the real world. Hint: Contrary to the lumped circuit
model, *everything* has a delay in the real world. The only place
coils don't have a delay is in your mind where miracles and
magic are possible.

The loading coil causes a phase shift in accordance with the
laws of physics. The stinger causes a phase shift in accordance
with the laws of physics. The impedance discontinuity between
the coil and stinger causes a phase shift in accordance with
the laws of physics. There are NO missing degrees.

When you comprehend how an electrical 1/4WL stub can be 19 degrees
of 450 ohm line plus 18 degrees of 50 ohm line and be physically
0.1 WL long, then you will have comprehended reality.
--
73, Cecil http://www.qsl.net/w5dxp

Cecil,
Now we have special case of biiiig coils being antenna here.
Let the games begin!

Yuri

"Cecil Moore" wrote to W8JI:

When you comprehend how an electrical 1/4WL stub can be 19 degrees
of 450 ohm line plus 18 degrees of 50 ohm line and be physically
0.1 WL long, then you will have comprehended reality.
--
73, Cecil http://www.qsl.net/w5dxp

I suspect
that no two people here on r.r.a.a are in 100% agreement
on everything.

Surely you jest... Fight! Fight! Fight! Kinda reminds me of
Beevis and Butthead after eating too much chocolate..
K7ITM pretty much boiled it down to the raw minerals by
noting that the usual "shielded loops" only advantage is the oft
improved balance. I've already been through all this mess testing
them here...
And I've proven to myself that an open wire loop can be just as
good as a "shielded loop" just as long as balance is taken care
of. It's the balance that matters. If the two types are equally
balanced,
and the same size, they will act the same.
The rest is just fodder for bored old farts on a newsgroup.
Of course, many won't agree with me, and this would include Yuri,
since he believes a shielded loop is quieter than an open loop.
But I don't care.
It's a free country. Or I think it is... Sometimes I wonder these days

with all these goofballs we have in DC running the show.
MK

wrote in message
oups.com...

And I've proven to myself that an open wire loop can be just as
good as a "shielded loop" just as long as balance is taken care
of. It's the balance that matters. If the two types are equally
balanced, and the same size, they will act the same.

Sooo, in shielded loop the shield is the antenna according to W8JI and
worshippers. But you take the shield (W8JI antenna) away, now the wires are
antenna, some say don't need no stinkin' shield and "antenna" to work as an
antenna.


The rest is just fodder for bored old farts on a newsgroup.
Of course, many won't agree with me, and this would include Yuri,
since he believes a shielded loop is quieter than an open loop.
But I don't care.

Amazing how selective in reading and digestion of postings some people are.
They tend to ignore the reality and description of it, they pick on
selective "proof" of what they were taught and figered out.
I emphasize, that electrostatic shield on the loop antenna is effective on
close proximity radiation, within some fractions of a wavelength from the
source of interference/signal. It does not (significantly) affect band noise
or distant noise/signals. Anyone who can build shielded loop and test it
within local arcing source or test transmitter, can see the attenuation of
the said noise.
So shield works as a electrostatic shield, if you guys like it or not, or
refuse to admit.
It is not that I believe in that, I have experienced it, seen it, measured
it and it works, it is there and anoyne can verify that, contrary to
"theories" of those who "figured" it can't be.
Electrostatic shields work on principle of capacitance plate, being grounded
and side exposed to electrical/electrostatic fields shunting the field to
ground. Capacitor's one "plate" is the interference/signal source
(antenna) - other "plate" is the el. static loop shield, grounded, shunting
electrical fields to ground and preventing from entering the antenna.
(Something like that).

Sooo, antenna works without shield (not just my assertion), but when you
insert it in the shield then shield becomes W8JI antenna. So his shield,
untuned becomes antenna, but my tuned and tunable inside the shield antenna
is not the antenna? Makes as much sense as "there is equal current along the
loading coil doesn't matter what", riiiiight?


It's a free country. Or I think it is... Sometimes I wonder these days
with all these goofballs we have in DC running the show.
MK


We were better off with Clintonistas having orgies in WH while Bin Ladin
turbanites were running around, blowing up Americans and using our flight
schools, our planes to demonstrate their "religion of peace" in NYC WTC
inferno?

Let's stick to some reality in antennas.

Yuri, K3BU

On Wed, 17 May 2006 11:30:55 -0400, "Yuri Blanarovich"
wrote:

Electrostatic shields work on principle of capacitance plate, being grounded
and side exposed to electrical/electrostatic fields

There's a very simple test of this "shield." It relates to experience
and doesn't need for you to go to the library.

1.) Tack a wire across the gap.

Q. Do you still have signal?

A. No!? None????

Extra Credit Question:
Did the wire make the "shield" better, or worse?

73's
Richard Clark, KB7QHC

p.s.
from your experience, the answer to the initial question above may
vary. If in fact it does, it may bring new material for discussion.

"Richard Clark" wrote in message
...
On Wed, 17 May 2006 11:30:55 -0400, "Yuri Blanarovich"
wrote:

Electrostatic shields work on principle of capacitance plate, being
grounded
and side exposed to electrical/electrostatic fields

There's a very simple test of this "shield." It relates to experience
and doesn't need for you to go to the library.

1.) Tack a wire across the gap.

Q. Do you still have signal?

A. No!? None????

Agree!
That makes it Faraday shield, which stops any signal from entering inside of
the tubing.
I never asserted that Faraday shield or closed metallic enclosure passes any
signals or fields.
We are talking about electrostatic shield, which if removed, antenna works
without change, you put it back, it still works the same way plus it rejects
in its reactive near field region electrical field interference.
If it was to be antenna, then when removed, the rest should stop working as
an antenna, or what is the theory?

Extra Credit Question:
Did the wire make the "shield" better, or worse?

It turned it to Farady shield and prevented signals from exciting the
antenna inside.

Extra Credit Question for professor:
Q1: If electrostatic shield is added to small loop antenna and it attenuates
the interference or signals from its vicinity, does it perform the function
of a shield or antenna?
Q2: Can the piece of tubing that is grounded by its outside surface, acts as
a capacitor's plate and provide the path to ground for electric field in
vicinity?

73's
Richard Clark, KB7QHC

p.s.
from your experience, the answer to the initial question above may
vary. If in fact it does, it may bring new material for discussion.

I just wish that points of discrepancy were addressed, rather than parties
taking off on tangents fitting their convinctions and trying to weasel out
of the wrong statements.

73 Yuri, K3BU

On Wed, 17 May 2006 12:17:07 -0400, "Yuri Blanarovich"
wrote:

Extra Credit Question:
Did the wire make the "shield" better, or worse?

It turned it to Farady shield and prevented signals from exciting the
antenna inside.

It's still the same "1/2 inch copper water tubing (non ferrous
material passing the magnetic field)."

So, does that wire make the "shield" better, or worse?

Super-extra credit question:
If we replaced the non ferrous material (same gap, no link) with (most
have probably anticipated this) a ferrous material, does this allow
near field region electrical field interference to pass un-impeded?

73's
Richard Clark, KB7QHC

On Wed, 17 May 2006 10:19:39 -0700, Richard Clark
wrote:

It's still the same "1/2 inch copper water tubing (non ferrous
material passing the magnetic field)."

So, does that wire make the "shield" better, or worse?

Hmm, this one must've been experienced exactly as an existential
question about the infinite cosmos.

Super-extra credit question:
If we replaced the non ferrous material (same gap, no link) with (most
have probably anticipated this) a ferrous material, does this allow
near field region electrical field interference to pass un-impeded?

This one must never been experienced either. I've always wondered why
perfect academic set-ups like "non ferrous material" (as if it were
lossless) always appear in the context of a populist aw-shucks kind of
posting.

Sorry All,

But when such simple questions become imponderables of the century,
they merit Cecil's 5 forbidden words woven in. Of course, it makes
only the most strained of sense, but there's nothing to compete! ;-)

73's
Richard Clark, KB7QHC

p.s. as viewed through the bottom of a bottle of Dick's Working Man's
Brown Ale (Centralia, Washington)