[R-390] Microphonic Parts?

[Barry]

> Looking at the resistor, it appears to be a rather special looking unit,
> unlike the other carbon comps used in the other circuitry.  There are other
> 10M units that are plain old carbon comp.  Not sure why they would want
> such a different style resistor there.  I don't have a parts list for this
> model so I can't verify anything specific about it.  It does measure very
> close to 10M, though.

Looking closer, this is a Welwyn Panclimatic C22 10M resistor.  Apparently these were very high-quality units for their time.  Not sure why it would be more inclined to make noise, though.

Any experiences with these?

Barry - N4BUQ