But some matching circuits provide frequency selective filtering. At least
the Tee tuners provide high pass filtering, and Z match tuners provide band
pass.
The other difference and why you can't do this with RF, is that most of the RF
output stages are not as linear as audio stages, and you need the tank
circuit, (tuned circuit) to make a sine wave out of the spike that is the
class C signal in the output transistor, or to smooth up the Class AB signals,
that conduct more, but less than 100 % of the RF Cycle. In other words, the
tuning eliminates harmonics and spurious output signal artifacts.
The duty cycle in Audio is nearer to 100 % unless a switcher audio amplifier,
and RF cycle can be over a wide variety of percentages less than 100 % signal,
which is another way of saying the output of the RF stage is not the sine wave
that audio output is.
Stuart K5KVH
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