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Old September 6th 06, 12:40 AM posted to rec.radio.amateur.antenna
Owen Duffy Owen Duffy is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 168
Default Dipole with standing wave - what happens to reflected wave?

On Tue, 5 Sep 2006 18:04:36 -0500, "Richard Fry"
wrote:

"Owen Duffy" wrote:
But, the mechanism is not that the reflected wave *necessarily*
travels all the way back to the PA anode by virtue of some kind of
momentumne / feedpoint junction are fully satisfied with no
reflected wave on the feedline. (I used the term resolve, Cecil must
call it destructive interference.) The reflected wave on the dipole
does not have a momentum that *must* carry it to the PA anode to be
absorbed there.

_____________

However, any amount of reflected power from the termination at the far end
of a transmission line has a greater chance of damaging tx PA components,
and of stress/failure to the transmission line itself than if the reflected
power from the antenna/load was zero, regardless of the electrical length of
said transmission line.


If it makes you more comfortable to restrict your solutions to those
with flat lines (VSWR~=1) then that is ok with me, but that does not
invalidate other approaches. Antenna systems incorporating lines with
high VSWR do not necessarily subject the PA components to any
different risk, or transmission lines to excessive stresses, it is a
matter of design... and the design is more complex than buying a tx
intended for 50ohm load, some 50ohm coax and a 50ohm antenna and
plugging them all together.

Owen
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