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Old December 21st 05, 09:29 PM posted to rec.radio.amateur.antenna
Owen Duffy
 
Posts: n/a
Default Standing Waves (and Impedance)

On Wed, 21 Dec 2005 20:18:05 GMT, John Ferrell
wrote:

On Tue, 20 Dec 2005 03:41:41 GMT, "W. Watson"
wrote:

I'm trying to make
some sense out of why the emphasis of standing waves.


Here is the short version:
A matched transmission line behaves like the theory books say it does.
The rated power from the transmitter goes through the transmission
line with the lowest possible loss to the antenna where it is radiated
just like the book says.


It is true that reducing SWR for a given line does reduce the loss if
the line is long enough. (There are some scenarios where a short line
with high VSWR has less loss than matched line of the same length.)

But is matched line the real goal?

If low loss is the goal, there are often cost effective lower loss
solutions possible with lower loss line operated at high VSWR.

A mismatched transmission just MIGHT work OK. If there is any
possibility of generating interference, especially TVI, it will. The


Why? How is TVI "generated" by line mismatch?

Owen
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