[sdiy] Black Magic oscillator cans

[Glen]

At 07:32 PM 7/20/03 , Tim Ressel wrote:

>Someone mentioned an LC oscillator. I think I have an adjustable cap
>somewhere.

I mentioned the LC oscillator. However, they are usually tuned with
variable inductors. Kimball, Baldwin, and other organ makers did it this
way. The variable inductor is generally less sensitive to mechanical
vibration than the variable capacitor (unless we are talking about using a
diode as voltage-controlled capacitor). There may have been other reasons
for the variable inductor as well.

I can see one little problem with the variable inductors that were usually
used in organs. They were not panel-mounted devices. You typically inserted
a plastic allen wrench into a slug-tuned inductor to make the adjustment.
These adjustments were located inside the instrument and not made available
to the end user.

If you already have a variable capacitor of an appropriate size, you could
certainly try it out. I'm just letting you know what was traditionally done
in the past.


later,
Glen Berry