Re: Loading Coils; was : Vincent antenna

Richard Clark wrote:
On Fri, 14 Dec 2007 05:18:03 -0800, "Roger Sparks"
<rsparks@xxxxxxxxxx> wrote:

That IS what I said. Think of the velocity as a moving wall, with the capacitor charged behind the wall, uncharged in front of the moving wall.
....
Be real. This experiment can be performed, and the DC switched as frequently as desired. How square the wave front will be depends upon real world factors.

Go to a transmission line characteristics table and use the formula to compare Zo, capacity per length, and line velocity. It will amaze you.

Hi Roger,

Take a deep breath, exhale, give what's above some more thought in
light of many objections.

Now, tells us just what significance any of this has in relation to
already well established line mechanics? It certainly isn't different
within the confines of its limitations if that is what you are trying
to impress upon the group. I suppose for a mental short-cut it has
some appeal, we get too many theories here based on approximations to
stricter math. One such example is when an equation of approximation
has forgotten the underlying |absolute value| and suddenly an inventor
arrives with a "new" theory that discovers uses for negative
solutions.

Further, there is nothing DC about it at all. DC is either static
(and in spite of Arthur's corruption of the term, that means no
movement whatever) or it is a constant unvarying current. A
succession of distributed capacitors rules unvarying current out (and
if it isn't already obvious, those unmentioned distributed inductors
in one of your links do too) - hence the step, hence the infinity of
waves, and from this, real world dispersion which kills the step
enough to make that varying current apparent enough so as to remove
all doubt.

73's
Richard Clark, KB7QHC

Hi Richard,

The math seems to work, but if you have no use for it, disregard it. On the other hand, if another perspective of electro magnetics that conforms to traditional mathematics can provide additional insight, use it.

I am surprised at your criticism in using DC. To me, a square wave is DC for a short time period. Is the observation that a square wave can be described as a series of sine waves troubling to you? Perhaps the observation that a square wave might include waves of a frequency so high that they would not be confined in a normal transmission line is surprising or troubling to you?

My goal is to better understand electromagnetic phenomena. You have given some very astute insight many times in the past and thanks for that. Negative comment is equally valuable, but sometimes a little harder to swallow.

73, Roger, W7WKB

.

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