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TS DX500V, convert to class C?

The conduction angle does change in the transitor allowing for higher outputs. But the fact that the bias voltage drops due to heat, is what pushes these amps into class C when they get hot.

Monitor the current consupmtion and peak output when the amplifier is cold. Then, using the same amount of drive, monitor the current and peak output.

You will notice one of two scenarios. The amplifier produces more power with the same or less current draw, or the amplifiers output stays constant and the current consumption drops. Ive done this with a TS350 and 500V, and both amplifiers went from a low 70% efficiency to high 70, low 80% region.

This was measured using an inline current meter, LP100a and IFR1600

i would say something else in the amp is likely drifting, i never saw an increase in output for the same drive by reducing operating point from AB to C as you said in your first post,
texas stars that i have heard don't sound to drift into class C on ssb as they heat up,
are you measuring idle current when the amp is cold then again when its warm?
 
The Idle current with the Texas Stars will vary with the transistor, and sandbar resistor tempeture. (being that they do not go to high in resistance)As well as the resistance of the 10uh chokes.

the ideal idle current setting for these amplifiers is 60 milliamps per transistor, or 120 ma. per board.
 
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