In reply to:
Ah. The 2220B has a manual tuner in it. I assume it does something nasty to the rubber?
Whoops, was going to respond to this earlier and forgot... I just wouldn't try cleaning a manual tuner with anything stronger than isopropyl alcohol... if they slip, the dial becomes useless, kind of finicky things.
Best results for cleaning is IPA (isopropyl alcohol) @ 100%; off the shelf "rubbing alcohol" is 70% IPA/30% de-ionized water usually... but sometimes can contain ethanol in some volume, not sure if it IS detrimental to electronics but I won't take the chance of using Russian vodka to clean my pots.
Bren R.
