Re: audio modulated SSTC

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Antonio Carlos M. de Queiroz" <acmq-at-compuland-dot-com.br> 

Tesla list wrote:

 > Original poster: herwig.roscher-at-gmx.de

 > - Same to me. Thinking of these new ways of modulation, I
 > unfortunately found out, that I do not fully understand the "old"
 > classes of operating RF power amplifiers either:
 >
 > Class A: conduction angle 360 deg - maximum linearity - no tank
 >                circuit necessary
 > Class B: conduction angle 180 deg - fully acceptable linearity - tank
 >               circuit necessary
 > Class C: conduction angle less than 180 deg - linearity is extremely
 >                poor, despite a tank circuit is necessary
 >
 > The latter statement I do not understand: Why is the linearity so
 > poor? Because of the flywheel effect the correct waveform should be
 > restored and Class C *oscillators* do this without problems. How is
 > "linearity" defined? Maybe I am thinking in wrong terms?

Linearity here applies to modulation linearity. Class C amplifiers
need a high-Q tank, and itīs difficult to vary the amplitude of the
oscillations rapidly, or even in linear proportion to a signal
modulating the power supply.

Antonio Carlos M. de Queiroz