On Mar 24, 12:40 pm, Cecil Moore wrote:
Keith Dysart wrote:
Standard analysis can tell us quite a bit about the situation
without the need for further information. The information
we have:
- Generator with 450 Ohm output impedance

There are a number of techniques to ensure that the
reflected waves encounter an impedance of 450 ohms
but none of those techniques are implemented in
amateur radio transmitters. Your generator is
obviously equipped with a circulator load of 450
ohms, 450 ohm attenuation pads, or some active
feedback.

While it might be, none of the above are necessary nor
included in the example I have analyzed.
A simple voltage source in series with 450 Ohms resistor
or a current source in parallel with one will produce
exactly the same results.

Look carefully at the analysis and you will find no
evidence of any of the items you have mentioned above,
unless you consider the 450 Ohm resistor to be an
attenuation pad. (Though it is this resistor which matches
the line and ensures there is no reflection).

Given that, your analysis is correct but
moot. Your point is already known and accepted by
every initiated person including me.

Not you, I suspect, since you seem to find it necessary
to add some components which were not in the description
of the setup.

I freely admit that if the proper circulator load
exists or if 450 ohm attenuator pads exist, they
will dissipate the reflected power by heating
up the circulator load resistor or the pads.

Yes, indeed they would. The more challenging case for
you is the example I presented without these components.
How do you explain the absence of ghosts? And the
unaccountability of the 'reflected power'.

While an example with a circulator makes it easy to
locate and account for the 'reflected power', there is
more to be learned by studying the example without.

If you can not demonstrate a flaw in the analysis then you
may wish to explore why the example without a circulator
(or other additional components) causes you difficulty.

But it's tough to argue that there is no energy in
the reflected waves while they are being used to boil
water.

While you can construct examples where the 'reflected
power' will boil water, there are alternate examples where
the total system dissipation drops in the presence of
'reflected power'. So sometimes 'reflected power' boils
water and sometimes it does not. Not a very reliable source
of energy it seems.

But I do suggest going back to the example. If there is no
flaw in the analysis, please explain where the 'reflected
power' goes.

....Keith