On Sun, 19 Mar 2006 12:41:43 GMT, Cecil Moore
wrote:

Owen Duffy wrote:

Cecil Moore wrote:
Please see http://www.qsl.net/w5dxp/current.htm

I refer to the diagram in the section entitled "What EZNEC Says About
Current Distribution Using Inductive Loading Stubs"

You use the diagram to assert that there is "not a lot of difference
between inductive loading stubs and loading coils" by comparing the
current distribution with another case.

You show graphically the current on each side of the stub. You do not
show the current in each wire of the stub or the sum of the currents
in the stub.

The currents in stubs cannot be displayed very well at full size in
EZNEC just as the currents in coils cannot be displayed very well.
Maybe an enlarged view would show it. I will try to do that.

Or even words that explain that the diagram is incomplete, that there
are currents flowing in the stub wires, and that they don't balance
each other so they participate in the antenna's total current moment.

The currents in the stubs is an explanation for the difference in the
currents in the main radiator at each side of the stub connection.

Is it fair to say that though the diagram may resemble the first
diagram on the page, to some extent, the reason they are similar is
that the second one is incomplete.


EZNEC calculates the currents in each wire of the stub? Aren't those
currents a relevant detail that you have omitted from the diagram.

Remember the present discussion is about the ability to use standing
wave current phase to measure the electrical length of a wire or a
coil. I have run the currents that you mention. The phase of the current
is almost constant through the stubs. The phase of the current is
almost constant through the coils. Would you like to see a list
of the current at points through the stub Vs the current at points
through the coil?

No thanks, I didn't ask the question without creating a model and
inspecting the currents.

The phase of the currents is only one dimension. Though the phase of
the current in adjacent segments in all wires (including the stubs) is
commonly similar (except where a phase reversal occurs), in general,
the magnitude and phase of paired stub segments that effectively form
a transmission line section are not equal in magnitude and phase.

My point is really about whether the subject diagram supports your
argument, especially if it is incomplete and if it misrepresents the
scenario.

Owen
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