In article ,
Reg Edwards g4fgq,regp@ZZZbtinternet,com wrote:
Arguments about whether the power ammplifier is matched or not matched to 50
ohms arise due to misunderstandings about the meaning of "matched".

Meaning 1.
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The PA has been designed for maximum, linear, undistorted power output when
loaded with Ro ohms and the load reistance has actually been adjusted to
equal Ro. Ro is usually 50 ohms. (There may be additional criteria to
define what constitutes an optimum match.)

Meaning 2.
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The load impedance Z = R+jX has been adjusted to equal the conjugate of the
internal impedance resistance of the PA. (The internal impedance of the PA
is usually unknown but the circuit is assumed to behave as if a conjugate
match exists.)

Meaning 3:
The PA has been designed to deliver the maximum power at that load
impedance and the distortion is not an issue.


The two meanings are entirely different from each other. If there is danger
of confusion then the meaning should be stated. Some people already use the
descriptions "Zo match" and "Conjugate match".

Actually meanings 2 and 3 are effectively equal in the case of the tuned
system, if you define the Zo based on the change in output power vs
connected impedance for small changes. Since a lot of such systems aren't
linear, this is the way you end up having to define the impedance. You
can't use open circuit voltage and short circuit current.

Remember that this all started with the OP having a "transmitter". This
would include any needed filtering. He was just connecting a 1/4 and 1/2
wave lengths of bent up wire. His output filter, I assume is just a bunch
of LC sections.



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