The black stuff is likely silver oxide, which is conductive. It can usually be left alone. OTOH the tarnish removers will strip come of the silver that you want to keep.
On Sat, 7 Dec 2024 09:55:59 -0800
"VE7PS via groups.io" <ve7ps@...> wrote:
That oxidation can be polished off with a bit of Tarn-X or other silver
polish. Might be easier dipping it in a *liquid *type of silver polish
first.
--
73
-Jim
NU0C
Jim Shorney