[Boatanchors] Disc caps vs paper caps

[J. Forster]

Prove it.

-John

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> I have noticed enormous amounts of drift in Colpitts-type crystal
> oscillators using some
> types of ceramic capacitors in the loop. This resulted in significant
> chirp
> on each key down.
>
> I don't know whether this is due to some form of self-heating, but the
> capacitance changes
> were so large that I can readily imagine that if you scaled the values up,
> and used these
> capacitors in an audio coupling network, that you should be able to detect
> the nonlinear
> change of time constant with input readily enough using both normal ears
> or
> some sort
> of audio spectrum analyzer.
>
> 73, ian K3IMW
>