[AMRadio] 807's triode connection question...

[Bob Bruhns]

Hello Howard,

I never ran 813s in triode connection, but here's what I
have on the subject, from AM posts by Bill Kleronomos,
KD0HG, and Mike Dorworthm K4XM.

Also I believe the series screen grid resistor idea (about
4.7K unbypassed to each screen grid) should work with 813s
in tetrode connection, if you want to play with that.  Just
be careful if you try it; if there is serious secondary
emission, the screens won't behave as they need to for that
mode of operation.  But I think it will work.  This hookup
wants the same plate Z as comparable tetrode operation, but
maybe 50V more is needed from the screen supply, which
should be regulated, and slightly more negaive control grid
bias to compensate for the higher quiescent screen voltage.
Try different screen resistor values for minimum distortion.

  Bacon, WA3WDR
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