Rich comments;
>I agree that you do indeed have RF negative feedback. I do not agree
>that grid current decreases distortion in any grid-driven
configuration.
>Rich---
Rich, there's a body of opinion that doesn't agree with you. For
example, see the curves of IMD against grid volts in The Care and
Feeding of Power Grid Tubes. My copy is the third printing,, and it's on
page 72. Actually, it graphs the calculated IMD products for the ratio
of RF grid volts to bias volts over a wide range. It assumes a perfect
tube, (which it says) and NO limiting at the output (which it doesn't
say). Also see Single Sideband Principles and Circuits by Pappenfus,
Bruene, and Schoenike, published by McGraw Hill in 1964, Ch 13-3, P191.
A reference to second harmonic distortion cancellation with grid current
can also be found in Terman's radio Engineering, 3rd edition, 3rd
impression, McGraw - Hill 1954, p.275
I'll be away for probably a week. Have fun, guys.
73
G3RZP
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