On 16 mayo, 22:29, Cecil Moore wrote:
On May 16, 2:58*pm, Wimpie wrote:

A CLC pi filter doesn't know the difference between:

1. 100 Ohms lumped circuit load
2. RC = +0.33333 (for 50 Ohms reference)
3. VSWR = 3 (voltage minimum, for a 300 Ohms reference)

It seems you don't want to notice that.

It is not worth wasting my time to notice since *everyone* already
knows that a CLC pi filter is not alive and doesn't have a brain so it
must necessarily be dumb as a dead stump. You, OTOH, hopefully being
smarter than the average CLC pi filter, should know that the
conditions existing within a resistor are different from the
conditions existing within an antenna with the same feedpoint
impedance. Hint: If you don't know what is in the box, alleviate your
ignorance by looking inside the box. If you put on the blinders and
refuse to look, then you will make errors like you did earlier while
measuring an s11 of zero when it was actually 0.3333.

Even the L of the CLC filter, you can model with a lumped circuit
equivalent with more than sufficient accuracy.

When the task is to determine the exact delay through the inductor,
how the heck can the lumped circuit model tell you that?

Just via the capacitance to ground (for example a CLC model of an
inductor well below the first self resonance frequency). But when
looking to a PA, there is often an additional capacitance left and
right of the inductor that causes the most of the phase shift. I did
some tesla coiling, so I am aware of the various models for single
layer inductors. You are further drifting away from the main subject
(PA output impedance and what mismatch will do).

--
73, Cecil, w5dxp.com
"Halitosis is better than no breath at all.", Don, KE6AJH/SK


Wim
PA3DJS
www.tetech.nl