On Sun, 28 Nov 2004 18:41:44 GMT, Richard Clark
wrote:

On Sat, 27 Nov 2004 21:43:14 GMT, (Robert Lay
W9DMK) wrote:

I can see now that the
Additional Losses Due to SWR really are dissipative and are unrelated
to the "Mismatch Losses" and "Transducer Losses" defined on page 22-12
of the ITT Handbook, 5th Ed.

Hi Bob,

I've let this simmer for a while, but I have to return to this because
you've erred in interpretation of this particular page and those
particular subjects. They are entirely caloric losses, not what you
dismiss as the myth of mismatch loss.

You need only review the math offered to observe they use the
conventional "real" line loss and add more "real" line loss in
proportion to the reflections at either one or two interfaces. The
equations are quite literal to this and explicitly state:
A0 = normal attenuation of line


I goofed on the part that is talking about transducer loss. I should
NOT have included the "Transducer Losses" in my statement above. The
Transducer losses do, as you say, include the normal attenuation of
the line, which is indeed a dissipative loss.

If you want deeper math, one source can be found in Chipman's (as
unread as any here) "Transmission Lines."

This is yet another of my references that attend to my recent, short
thread on the nature of power determination error, and mismatched
loads AND sources. In fact ALL of these references I've offered
explicitly describe that the source MUST be matched for ANY of these
equations about transmission lines bandied about to accurately offer
true answers. The naive presumptions that Source Z is immaterial to
the outcome of analysis is quite widespread here.

Chipman offers the rigorous math that attends explicitly to the Smith
Chart loss nomograph you reference elsewhere in this thread. If you
lack access to this work, I can munge up the equations here for you.
I will add, this math is for "lossless" lines, as is the implication
of the Smith Chart nomograph; but it only requires you to add that in
for yourself by restructuring the math to include loss. At that level
of granularity, it won't be pretty; but you can rest assured it will
be complete.

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. Everything ever
written that I have seen about the Smith Charts agrees that the actual
losses in the transmission line are indicated by the collapsing of the
circle as one traverses the transmission line. All you have to do is
read the "loss in 1 dB steps" scale to determine those losses.


Bob, W9DMK, Dahlgren, VA
http://www.qsl.net/w9dmk