On Thu, 25 May 2006 21:38:45 -0700, Roy Lewallen
wrote:

Time-varying electric flux can indeed penetrate thin
shields of finite conductivity, although the E/H ratio within the shield
is very small.

A gapless shield made of a perfect conductor of any thickness will
completely block both electric and magnetic fields.

Hi Roy,

Given the vast gulf that separates these two observations above, and
the oblique reply in general that does not flow from your previous
question that I responded to.... It seems you are answering a topic I
have not entered into, or restating what I've already offered.

73's
Richard Clark, KB7QHC

Richard Clark wrote:
On Thu, 25 May 2006 21:38:45 -0700, Roy Lewallen
wrote:

Time-varying electric flux can indeed penetrate thin
shields of finite conductivity, although the E/H ratio within the shield
is very small.

A gapless shield made of a perfect conductor of any thickness will
completely block both electric and magnetic fields.

Hi Roy,

Given the vast gulf that separates these two observations above, and
the oblique reply in general that does not flow from your previous
question that I responded to.... It seems you are answering a topic I
have not entered into, or restating what I've already offered.

Sorry, once again I miss your point. I maintain that time-varying
electric and magnetic fields cannot exist independently, while you claim
that they can. Tom and I asked for an example of a case where they do,
and your response did not contain such an example.

Roy Lewallen, W7EL

On Fri, 26 May 2006 11:10:28 -0700, Roy Lewallen
wrote:

while you claim

Hi Roy,

The courteous thing would be to quote me directly rather than
paraphrase me obliquely. Respond to the posting you find
objectionable.

73's
Richard Clark, KB7QHC

Richard Clark wrote:
On Fri, 26 May 2006 11:10:28 -0700, Roy Lewallen
wrote:

while you claim

Hi Roy,

The courteous thing would be to quote me directly rather than
paraphrase me obliquely. Respond to the posting you find
objectionable.

I did. I responded to the lengthy posting you reposted. Your response to
that was, unfortunately, incomprehensible to me, and not apparently
related to the topic in question. But here's what you've said, and with
which I disagree -- that is, if I understand what you've said; I often
don't. Alas, I was too often in the back room soldering things together
when I should have been doing my English homework. (And see what it's
done: not only poor comprehensive skills but split infinitives to boot.)

------------

On 24 May 2006 17:31:59 -0700, wrote:

[Tom wrote:]
This is part and parcel to the world of isolated and shielded
circuits. The electrostatic shields are as effective as they are
complete in their coverage. Their contribution is measured in mutual
capacitance between the two points being isolated.

I don't have that reference and so cannot see that shield, but the only
thing the shield can do is reduce field impedance by changing the ratio
of electric to magnetic fields. In order to take either one to zero the
other must also be at zero.

[You responded:]
Hi Tom,

There are too many contra-examples too sustain your point. What you
are talking about is radiation, this does not account for common
induction that occurs on the very short scales I've offered.

73's
Richard Clark, KB7QHC

-----------

And:

-----------

On Wed, 24 May 2006 12:11:52 -0700, Roy Lewallen
wrote:

Richard Clark wrote:
. . .
Richard's applications and illustrations do not push this
boundary. In
fact, Ramo et. al distinctly offer the case of "electrostatic
shielding" and clearly support the separation of magnetic and
electric
flux (fields). . .


[I responded:]
Can you direct me to where in the text they do so? All I've found is a
short section (5.28) on "Electrostatic Shielding" where they explain
that introducing a grounded conductor near two others will reduce the
capacitive coupling between them. Obviously this will alter the local
E/H ratio, but in no way does it allow an E or H field to exist
independently, even locally, let alone at any distance.

[To which you replied with the lengthy post which you were kind enough
to post a second time. Hopefully a third time won't be necessary.]

------------

Am I mistaken, then? Were you agreeing all along that a time-varying
electric or magnetic field can't exist independently and therefore there
can't be completely inductive (H field) or capacitive (E field) coupling?

Roy Lewallen, W7EL

On Fri, 26 May 2006 16:40:46 -0700, Roy Lewallen
wrote:

Hi Roy,

But here's what you've said, and with which I disagree

What appears to be the only content you disagree with:

There are too many contra-examples too sustain your point. What you
are talking about is radiation, this does not account for common
induction that occurs on the very short scales I've offered.

And:

Richard's applications and illustrations do not push this boundary. In
fact, Ramo et. al distinctly offer the case of "electrostatic
shielding" and clearly support the separation of magnetic and electric
flux (fields). . .

We never actually get to what it is that is disagreeable do we? This
is merely the window dressing for backing into an oblique translation:

Am I mistaken, then?

Who can tell but you? It is, after all, your statement that you
disagree. We can only guess.

Were you agreeing all along that a time-varying
electric or magnetic field can't exist independently and therefore there
can't be completely inductive (H field) or capacitive (E field) coupling?
A 30 word speech dressed as a question is not clear writting. :-)

Agreeing all along?
No, I am never in the habit of agreeing all along.

A time-varying electric or magnetic field can't exist
independently?
Fields in free space are intimately joined and inseparable.

There can't be completely inductive (H field) or capacitive (E
field) coupling?
If I am not mistaken, this is the same question again. Do you in fact
see any difference between the two that merits the boolean AND?

Should I anticipate other philosophical questions such as
Are you agreeing all along about conductivity and Ohm's law?
Let me shock you and say NO so as to not deflate others' anticipation.
I bet they will know how to pin me down. ;-)

73's
Richard Clark, KB7QHC

Wow, you got me there. I'm so used to communicating with engineers that
I was actually expecting a direct and coherent response. Silly me.

There was one clear and unambiguous statement in your response, though:

Fields in free space are intimately joined and inseparable.

So we don't disagree after all. I see now that in your previous postings
"contra-examples" really means "supporting examples", and "Ramo et. al .
.. . clearly support the separation of magnetic and electric flux
(fields)" really means they reject it. You can really do amazing things
with the English language. I'm in awe.

Roy Lewallen, W7EL

Richard Clark wrote:
On Fri, 26 May 2006 16:40:46 -0700, Roy Lewallen
wrote:

Hi Roy,

But here's what you've said, and with which I disagree

What appears to be the only content you disagree with:

There are too many contra-examples too sustain your point. What you
are talking about is radiation, this does not account for common
induction that occurs on the very short scales I've offered.

And:

Richard's applications and illustrations do not push this boundary. In
fact, Ramo et. al distinctly offer the case of "electrostatic
shielding" and clearly support the separation of magnetic and electric
flux (fields). . .

We never actually get to what it is that is disagreeable do we? This
is merely the window dressing for backing into an oblique translation:

Am I mistaken, then?

Who can tell but you? It is, after all, your statement that you
disagree. We can only guess.

Were you agreeing all along that a time-varying
electric or magnetic field can't exist independently and therefore there
can't be completely inductive (H field) or capacitive (E field) coupling?
A 30 word speech dressed as a question is not clear writting. :-)

Agreeing all along?
No, I am never in the habit of agreeing all along.

A time-varying electric or magnetic field can't exist
independently?
Fields in free space are intimately joined and inseparable.

There can't be completely inductive (H field) or capacitive (E
field) coupling?
If I am not mistaken, this is the same question again. Do you in fact
see any difference between the two that merits the boolean AND?

Should I anticipate other philosophical questions such as
Are you agreeing all along about conductivity and Ohm's law?
Let me shock you and say NO so as to not deflate others' anticipation.
I bet they will know how to pin me down. ;-)

73's
Richard Clark, KB7QHC

On Fri, 26 May 2006 21:18:13 -0700, Roy Lewallen
wrote:

There was one clear and unambiguous statement in your response, though:

Fields in free space are intimately joined and inseparable.

Hi Roy,

This statement inspired you to manufacture the following as being my
meaning?

So we don't disagree after all. I see now that in your previous postings
"contra-examples" really means "supporting examples", and "Ramo et. al .
. . clearly support the separation of magnetic and electric flux
(fields)" really means they reject it.

73's
Richard Clark, KB7QHC