[AMPS] Re: New G2DAF amplifier information

[Peter Chadwick]

Rich says:

> Since the typical grid terminating resistor is 450 ohms, instead of the
>exciter seeing a 50-ohm load through the 1:9  transformer, it now sees a
>191/9 -ohm load.  

Rich, the argument is this:

You claimed that running grid current in a grounded cathode tetrode caused
distortion. You at least implied that this was always and  inevitably the
case.

I claim that this is not necessarily so. The caveat is that the design takes
care of grid current loading, provides stable bias and screen supplies, and
that the tube is suitable.

Further, there is a large body of professional literature over the years
showing how to achieve satisfactory Class AB2 operation of tetrodes. The
G2DAF does not to my mind, necessarily, with all tubes and arrangements,
fall into that category. I am willing to concede that with some tubes and
some time constants, it could be satisfactory (There are more things in
heaven and earth, Horatio, than are dreamt of in your philosophy)

End of story.

73

Peter G3RZP



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