[Amps] low Q output matching

[peter chadwick]

>Regarding flywheel effect and restitution of the half cycle in which the 
tube doesn't conduct, that's the exact same thing as suppressing the 
harmonics. Any low pass filter that achieves good harmonic suppression 
will nicely restore the sine waveshape<
True, but one cannot forget the result on IMD - unless the filter is an absorbtive type, it will reflect the appreciable second harmonic energy back to the valve anode. If it IS an absorbtive type, it will lose about 50% of the power.
The OP was talking about an amp for 160m, so the capacitance problem isn't so bad, but even on that band,  50pF of valve plus stray capacitance will be such as to give an elliptical load line and thus phase distortion, doing no good for the IMD performance.
You can get around the capacitance problem in a wide  band amplifier by going to a distributed amplifier, but you use a lot of tubes and the efficiency is poor. 

73
Peter G3RZP