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Old August 28th 05, 06:07 AM
Wes Stewart
 
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On Sat, 27 Aug 2005 17:49:42 -0700, dansawyeror
wrote:

I am not sure what you mean by -always-. If you mean there is no such thing as a
perfect coax line then your statement is true but does not add any real value.
If you mean by -always- the feedline is a significant component in the antenna
system then I would have to disagree. When operated at their design point coax
transmission lines do not radiate and are not part of the radiating "antenna
system".



Well, now, we've just morphed "antenna system" to "radiating antenna
system."

But never mind, nothing's changed, you're still all wet. Of course
the feedline is a component in the antenna system regardless of
whether it radiates or not. BTW the line can be perfectly matched and
radiate or it can be highly mismatched and not radiate.


Coax is designed to work in a specific environment as a transmission line. These
transmission lines are designed not to radiate. When transmission lines are
operated significantly outside their design range the(y) radiate.


Squeak squeak---squeak squeak---squeak squeak, there I just screwed a
tee connector on the end of a run of 50 ohm coax and on the tee I
screwed on two 50 ohm loads. The line is now terminated in 25 ohm
making the SWR 2:1. 'Splain to me how well this line, "operating
outside its design range", radiates.

If that's not "significantly" far enough outside the "design range"
then allow me to remove the loads, add two more tees and terminate
them with four 50 ohm loads, making the SWR 4:1. How well does the
line radiate now? Should I continue to 8:1 or are you convinced?


Adding a tuner to
one end only controls the characteristics at that point. It does not 'clean up'
the mismatchs.


It can certainly "clean up" the mismatch at the input to the tuner,
which unless I've been deluding myself for 45 years or so, is the
point.