Doug Hall wrote:
> seems totally incorrect to me. What happens to the 1000 watts of
reflected
> power? Does it come back into the amp and just sit there? Of course not!
> It's reflected back up the feedline to the load, right?
Doug,
A complete discussion of reflected power would make a good textbook.
There are two ways to look at it, as voltage and current changes in the
line (the line as a circuit), or as wave theory.
Either method works perfectly in an analysis of the system.
No matter HOW you look at the problem, the answer is the same. The
reflected power is subtracted from the forward power, and the result is
the actual power. Only a poorly designed meter or a non-directional
meter would give a false reading.
NONE of the reflected power "makes it back" to the tube, unless the
pi-network is improperly tuned. When the network is adjusted for maximum
power transfer, the tube still sees a perfect load. Reflected power does
not even increase RFI or TVI, unless the line has common mode
(parallel) current problems.
Walt Maxwell's book "Reflections" handles the discussion nicely from the
wave theory angle.
73 Tom
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