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RE: That is where the rot creeps in

Posted by cpotl on June 15, 2021 at 14:50:41:
"Either both are grounded grid, or neither are, or they act like something in the middle...but they are the same."
Why do you say that? Whatever the other faults in Crowhurst's discussion, the principle of his analysis, based on his redrawing the schematic as in his Fig. 626, looks OK. (I was unhappy when I first encountered his Fig. 626 because he appeared, erroneously, to have taken the bottom end of Rk to ground rather than to a negative supply rail. But actually, for the small-signal analysis he is making, it doesn't change anything. All he needs for his analysis is that the bottom end of Rk is held at a constant voltage with respect to ground.)
Anyway, Crowhurst makes it look pretty convincing that V2 is a grounded grid, while V1 is not. Do you see any flaw in his strategy for the analysis?