You¡¯d want a transistor with a fairly low max Ic, since the junction area would be smaller, and thus tend to have lower capacitance. The 5769 probably has close to double the capacitance of the 3904. I haven¡¯t looked at a datasheet, so I¡¯m simply going by the max Ic rating ratio, so I reserve the right to be surprised by the actual numbers.
¡ª Cheers
Tom
Sent from my iThing, so please forgive typos and brevity.
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On Feb 22, 2021, at 3:37 PM, Charles <charlesmorris800@...> wrote:
?Thanks for all the interesting side discussion... Prof. Lee did answer my question, noting that there would probably be too much blow-by.
Too much to be adjusted out by the blow-by compensation circuitry in these heads?
How about a different fast switching transistor (say a 2N5769? I have scads of those).
I remember seeing those transistor B-E (or should I say E-B) clamps as a kid, back in the 70's transistorized designs from Heath. I always wondered why they did that... now I know :)
