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Old November 29th 04, 01:08 AM
Richard Clark
 
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On Mon, 29 Nov 2004 00:02:10 GMT, (Robert Lay
W9DMK) wrote:
I'm not sure what you are saying about the loss nomograph on the Smith
Chart. If that's wrong too, then we're in big trouble.


Hi Bob,

Chipman devotes an entire chapter on the Smith Chart, covering each
scale completely (I wonder why Reg thinks it would take so many months
to accumulate this information if he, as he alludes, is already aware
of Chipman's work.).

However, the nomograph discusses nothing in terms of any particular
line's dissipative loss as that is outside of purpose of the chart.
I'm afraid you are back in the mythical mismatch loss there. When Wes
puts that particular page online, then perhaps you may find a way to
fully describe your situation - including loss specific to your tests.

Chipman states quite bluntly:
"IF the transmission line of Fig. 9-26 is lossless...."

The point of my posts is that few actually read this material to
appreciate the very carefully stated premises. The problems arise
when derivative work is used as a source wherein that author presumes
that the reader is educated in the particulars that go left unsaid....
like all Sources' Z MUST match the line for any analysis to be valid.
Instead we get these trivializations of the matter that this is only a
concern inhabiting only specialty sources in specialty labs.

However, as applied to your recent work, the degree of mismatch
offered by your source is low enough to be negligible; but as you are
not aware of its degree, then neither are you aware of the scope of
your error.

73's
Richard Clark, KB7QHC