Dave Platt wrote:
In article ,
Gudmundur wrote:

Hi folks.

Wondering if anyone here knows a good way to clean and restore
life to the rotary cam finger switches like are used in Tek SC502,
SG503 etc.

Some Tek components come with a warning not to use anything stronger
or more persistent than high-grade isopropanol on their switches (e.g.
the attenuator switches in the 4xx-series o-scopes). These switches
incorporate materials which can be damaged by many organic solvents,
or are used in high-impedance circuits in which small amounts of
leakage current from contact-cleaner residue can mess up the behavior
of the circuit.

I don't have any of the blue and the red CAIG fluid anymore but
to anyone here who ever used it what do you think of the stuff??
I had two little bottles with a built it applicator brush and I
thought the stuff worked great!

Agreed.

Both the original (German) Cramolin products, and the DeOxIt
formulations which Caig is selling these days, seem to work quite well
for many of these sorts of problems.

My SG503 went bonkers and I used spray isopropyl alcohol and then
a small shot of WD-40 on the contacts. Seems o.k. now.

Ugh. I would never recommend using WD-40 on electrical contacts in
fine electronic equipment. It gets gummy with time, and attracts
dust. It may make things better in the short run but I fear that if
it's left in place it may cause further (worse) problems.


Agreed - WD40 is good for de-gumming your chainsaw, preventing rust on
garden tools, and freeing up rusted bolts, but thats about it. BP
grade isopropyl(sp) alcohol is readily available from chemical
suppliers - (A litre bottle will last you for EVER) - if you do insist
on a "tougher: lubricant, then CRC 2-26 is pretty good. BUT - as in
everything else - RTFM before you do ANYTHING!

Andrew VK3BFA.