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
|
|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.

Richard,

If you wouild cite the pages to which you refer, I would gladly scan
then to pdf and post them for all to reference.

Wes


|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.
|
|73's
|Richard Clark, KB7QHC