on 11/3/99 09:59, measures at measures@vcnet.com wrote:
> During the Great Debate,
> there were many stern warnings from critics of "The Nearly Perfect
> Amplifier" (Jan., 1994 *QST*) - to the effect that manufacturers don't
> use rheostats to control filament voltage (as per the article) because
> rheostats simply do not last in this application. The rheostat still
> works after a dozen years of service.
>
WHY? Why would a rheostat stop doing what a rheostat is supposed to do???
> One should keep in mind that above its self-resonant frequency, a
> capacitor looks like an inductor. For example, your typical 0.01uF
> disc-ceramic universal "bypass" capacitor looks like an inductor on 20m -
> 10m.
I agree with your comment. I am surprised though that the caps are that
poor. I know even most "quality RF" caps (mica or otherwise) begin to look
really bad above 30 MHz, but I am surprised things look bad above 14 MHz.
73,
Jon
KE9NA
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