Off-subject--sort-of!

[Fred Olsen]

Allen Heibeck wrote:

> The vintage test equipment- Heath, Tektronix scopes,
> etc,  used BNC connectors (silver-plated?) ...
> What is a safe way to clean-off years of oxidation
> without leaving an undesirable coating?

Allen, if the BNC is "on-Heath" it's "on-topic".
I've had good results cleaning precious metal connectors with Tarn-X.
It's strong, and will remove any patina in addition to oxides, but it
works.  Appropriate tools include cotton balls, toothbrushes, pipe
cleaners (mind the wires though), toothpicks - whatever will get where
you need to go.

The caveat is that a soap and water wash afterward is required, plus a
thorough rinse and complete drying.  Water removal can be aided by
flushing with isopropyl alcohol - assuming there's nothing in the way
which might be damaged.  The isopropanol should be pharmaceutical grade,
99% or better, without any water in it.  No "rubbing alcohol".
'Silver cleaners' and 'polishes' will leave abrasives, waxes, all sorts
of mess behind.  Fine for cleaning silver-plated RF cans without
destroying the patina, but not for connectors.


> What will clean the scope graticule without the
> lines coming off?

Always approach this with caution.  It's an individual-piece thing, and
also depends upon the markings being etched or silkscreened.  Some will
survive solvents, some won't tolerate water.  I'd suggest starting with
mild soap and water, applied with a Q-tip to the least conspicuous place
having markings.  If all is well try just using your hands with suds as
though you were washing them.  Use Fantastik, Formula 409, et al, and
alcohols or other solvents with extreme care on anything with markings.

As always, anyone should feel free to tell me how dumb I am (IF you can
point out why).  ;<)

Good luck,
Fred
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Outgoing checked by Norton AV.

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