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?Been an AMP user for almost 50 years. But have a question.

The Plate/load/coil match the tube(s) output impedance to the desired antenna impedance typically 50 ohms.

Just like a tuner changes a non 50 ohm antenna to 50 ohms.

But I just thought of this. in the antenna tuner the two caps can be and usually are all over the place.
And their tuning is typically rather broad. the caps are not super tight.

But in an AMP

The Plate control is very critical and narrow in optimum setting.
And It's level of "C" is almost predictable. You KNOW the 40 meter will have less "C" than 80 meters.
And so on through the bands.

The load cap is almost in the same position and in almost every amp I have had the optimum was rather broad.

Why?

Joe WB9SBD