Rich said:
"In order to achieve linear amplification, current gain must be constant
at All signal levels. Screen potential has a large effect on current
gain. At 33% of normal screen volts, an 8171 exhibits 1/4 of normal
current gain."
Rich, you keep ignoring the fact that as the screen voltage varies in the
G2DAF amplifier, the grid also varies. If they varied in proportion to each
other, then I agree that the circuit would not be linear. But the ratio of
grid to screen voltage varies throughout the change in drive from 0 to
maximum drive (because of the unique voltage doubler circuit). So, using
your 8171 tube, if the screen voltage did not increase in proportion to the
screen voltage, results could be linear. That is what the debate is about.
The probem is that you keep hedging your bet by defining the rules so that
your favored circuit will win by definition. Were you writing the rules
when the turbine cars tried to run at the Indianapolis 500? And, once they
met the rules and the turbine almost won the race, then changed them again
to effectively ban them.
Colin K7FM
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