Tony Angerame wrote:



I don't know if someone mentioned this I didn't see it but inside the
ceramic coil forms of the oscillator coils is a half turn of heavy wire
that you bend up and down within the cylinder of the form to aid or buck
inductance. Very stable good idea from National who, as I now find out,
had a much stabler almost drift free vfo with ceramic coils. (Unlike Halli)


Tony WA6LZH

I've got a coil here...not sure where it came from...possibly an LM or
BC221 freq meter that has a little internal winding on a mainspring
gizmo that rotates according to temperature. Quite clever.

-Bill