On Tue, 29 Nov 2005 14:14:15 GMT, Cecil Moore wrote:

Owen Duffy wrote:
Have it your way Cecil...

I hope you now see the advantage of being able to vary the
length of the ladder-line until a current maximum point is
located at the choke-balun. Knowing the impedance is purely
resistive and relatively low allows me to read it with my
MFJ-259B. That resistive point is on the ladder-line SWR circle
on the Smith Chart. An arc of the SWR circle is the known length
of the feedline which gives me the feedpoint impedance of the
antenna (and can be adjusted for losses).

Cecil, you have a single solution, and you are inclined to transform
every problem to require that single solution (read your posts).

Whilst step variable length transmission lines have application, they
are not the solution to every problem, or indeed, to many problems.
You are not the originator, nor the only user of such.

Since you mention the Smith chart, you are a champion of operating
transmission lines at very high VSWR, and yet would suggest that a
Smith chart can give you an adequate solution for the losses. That
says more of what you consider adequate than the suitability of the
Smith chart as a solver of that type of problem, especially in this
day and age. I suggest that the Smith chart loss solution is adequate
when you can ignore the losses.

I can visualise you sitting amidst an expensive heap of inch size
pieces of LDF5-50 and a Bird 43, slide rule and Smith chart, with a
caption "It is possible, and it is practical!".

Yes, you could say that I understand the advantages of a step variable
length transmission line. It is probably why they are used as much as
they are.

Owen
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