[TowerTalk] Tarnished connectors

[Richard (Rick) Karlquist]

On 8/20/2019 10:58 AM, k7lxc--- via TowerTalk wrote:
>>    Just wondering if anyone has found a way to remove the tarnish off of older connectors.?? The tarnish is not effecting the usage, but does distract from the appearance.
>      It they're silver, the visible silver oxide is a conductor so no need to do anything.
>      Removing the tarnish won't affect the signal so I wouldn't bother. Around here, the question is whether it makes a difference to the DX station. If it makes a difference - > Cheers,Steve     K7LXCTOWER TECH

This topic is actually quite controversial.  First of all, AFAIK,
"tarnish" is silver sulfide, not silver oxide.  Numerous
references say silver sulfide is NOT a good conductor,
even going to the extent of "debunking the myth" that it is.

When I worked for HP in atomic clock R&D, we discovered
that the silver plated microwave waveguides in our
model 5061B tarnished in areas where coal (containing
sulfur) was burned.  This would cause RF to leak out
of the waveguide and bounce around the chassis and
leak back in.  Removing the top cover (which should have
had no effect) would change the RF reflections.
For complicated reasons, this resulted in a frequency shift of the 
standard, which was called the "top cover effect."

The fix for this was to disassemble all the waveguide
pieces, clean up the tarnished surfaces, and then
reassemble everything.

I made sure to eliminate any silver plating and
replace it with gold plating in the model 5071A,
which replaced the 5061B.

Unfortunately, I don't remember what was used to
remove the tarnish, but you might be able to find
out by reading papers about the top cover effect written
by an Italian professor named de Marchi.

Rick N6RK