On 7 jun, 03:04, Richard Clark wrote:
On Sun, 6 Jun 2010 15:21:59 -0700 (PDT), Wimpie
wrote:

Try the following experiment:

-sigh-

Did you do the experiment (forward power versus mismatch)?

Hi Wimpie,

This is not what I asked for. *You said what the source was NOT, but
you cannot say what the source IS.

The source is not a bipedal reptile. *The source is not an elongated
diphthong. *The source is not the resurrection of a deity (some may
argue that more than I would care to follow). *The source is not....

There are many ways to say what the source is NOT, and that will never
inform us about the source. *I see many draw deuces to this question
and try to convince everyone that the card is a pair of winning aces.

Probably you consumed something wrong here.

Now make some mismatch (for example VSWR=2 at different phase) and
read the forward power. Did it change? If so, the output impedance is
no (longer) 50 Ohms.

What IS it now? *If you could measure it once, you should be able to
tell us what it is this time too. *I did this for years to methods set
by the National Bureau of Standards. *You have drawn a deuce, not two
aces.

Some values:
9 +/-1 Ohm (real impedance), reference impedance 16 Ohms, 8 MHz
amplifier (ISM). Exact value requried because of additional filtering,
based on several IRF110, push pull.

2 Ohms (small reactance present), 10V/1A driver (sinusoidal), 700
kHz, slightly saturating class C output stage based on single mosfet.
RF feedback present to guarantee value below 2 Ohms. also here,
certain maximum value was required for the application

|RC| 0.80 (actual value depending on type of additional filtering in
between), 5kW pulsed power amplfiier, non 50 Ohm application.
Actual value not important, but is a recent project, so I knew from
memory.

See also EL34 example in posting to Walt.



Measuring method used: change in resistive load, from voltage change
you can calculate the current change, hence the output impedance. One
note, except two, all where solid state.

Yes, that is called a load pull, but you offer no data - another
deuce. *I have done a lot of load pulls. *

All high efficiency designs (class E, D) that I did have output
impedance far from the expected load impedance. With "far" I mean
factor 2 or factor 0.5. I did not measure that (as it is not
important in virtually all cases), but know it from the overload
simulation/measurement and I did the design myself.

You didn't measure it, but you can state the value - interesting state
of guessing. *So, what did the simulation/non-measurement give you as
a value? *What IS the value? *Another deuce.

Please read again last part of sentence above your text.


The reason for not being 50 Ohms

Reasons abound. *BP is giving us reasons why the Gulf Coast shouldn't
worry. *Data has proven that reasons don't work and neither does their
well. *That is a Joker draw.

High efficiency CW amplifiers

The TS830S is not such an animal. *Another Deuce.

Not al hams use TS830S, See more recent reply of Walt to Tom's
posting.

If you can drop me a link to the discussion of the TS830s, I would
appreciate that.

Google "Plate Resistance" in this group.


73's
Richard Clark, KB7QHC

I hope, further replies from you will be constructive,


Wim
PA3DJS