On 19 mayo, 23:15, Cecil Moore wrote:
On May 19, 3:21*pm, John KD5YI wrote:

This is just plain stupid.

I agree. Your above posting is just plain stupid. You are stating the
opposite of what I have said hoping some readers will not notice.
Resistors exist *in reality* e.g. in dummy loads. You are promoting E/
I ratios, existing as virtual resistances, to be as real as a physical
resistor. Hopefully, no one ever loads his virtual gun with one of
those virtual resistances and fires it at you. Question is, would you
die or not? It has been said that everyone creates his own reality and
it must be true. You guys have created models of reality in your minds
that bear very little resemblance to the real world.

In the field of optics, an real image that actually exists in reality
is clearly differentiated from a virtual image which is an illusion
that doesn't actually exist where it appears to exist. Light waves are
EM waves. RF waves are EM waves. You guys are promoting a model that
considers virtual images to actually exist at the point where they
appear to exist but are only an illusion. I agree with you - that is
just plain stupid.

To summarize: Resistors, capacitors, and inductors, defined under the
concept of impedors (from "The IEEE Dictionary") are real-world
devices with a physical existence - one can pick them up and touch
them.

E/I ratios, containing resistance plus capacitive or inductive
reactance, are impedances that do not have a physical existence. Their
existence is conceptual and exists only in human minds capable of
concepts (much like the concept of God).

When you are standing four feet from a mirror and your image appears
four feet behind the mirror, you are arguing that you can replace your
actual self with an alternate self four feet behind the mirror and
everything will be exactly the same. I agree with you - that is just
plain stupid.
--
73, Cecil, w5dxp.com

Cecil,

I already expected that you wouldn't solve my brainteaser (so I did it
in advance), Here is the result for the 100V, 4 MHz sinusoidal source
in series with 796pF, load pulling with 51.2 Ohms and 44.6 Ohms:

V_out (51.2 Ohms) = 71.5V, I_out = 1.396A
V_out (44.6 Ohms) = 66.5V, I_out = 1.491A

Delta_V = 5.0V, Delta_I = 0.095A,

Hence Rout = 52.6 Ohms.

Power into 50 Ohms = 50W.

¡Really strange!, that a fully imaginary output impedance of -j50 Ohms
results in real 52.6 Ohms output impedance based on the scalar load
pulling referenced by you.

I also applied complex load pulling (that is taking phase change into
account) and Tom's off-carrier injection method to the same source.
Both methods put out Zout = -j50 Ohms (yes, the correct value).

You are criticizing Tom's method without any solid foundation, but you
referenced to a method with very limited application as shown in this
simple example.

You are mixing coherent signal theory with non-coherent signal theory
(narrow band RF versus unspecified optical), also your reply above has
no relevance to PA's for HF amateur service.

Cecil, we have all our specialities and limitations. It is becoming
clear that you lack experience in the field of signal processing and
RF (systems) Engineering. This is no problem, because many people can
live without it. Instead of continuing the way you do, you can better
try to grab some of the concepts offered by others. I am sure it will
give you better insight in what happens in RF systems, in considerably
less time.


Wim
PA3DJS
www.tetech.nl