Cleaning switch contacts on Scope

Dec 01, 2010 20 Replies

I have a scope and one channel has poor connections on the Volts/Div switch. What product would you use to clean the contacts on the wafer switch? MikeK PS. I've been dealing with it to long, time to fix it!


I gave mine a dose of "CO contact cleaner" and worked the switch back & forth a heap of times, better but not perfect.

Years ago there used to be stuff called "microscrub" for cleaning telecoms relay contacts but I havent seen it anywhere for years. There was also slips of pink paper looking material impregnated with solvents & a lubricant that was used for cleaning instrument contacts but again I have not seen this in catalogues for many years. Not much help hey!

Assuming that the problem is dirty and/or oxidized contacts, Deoxit D5.

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What model scope is it? Sometimes all that's needed is adjusting the bends in the contacts a bit.

Contact cleaner! The Radio Shack stuff is OK. A little spritz on the contacts, followed by some vigorous rotation, usually fixes things up. It works on pots, too: spray along the back, any seams, and into the bushing.

John

Be careful which contact cleaner to use, don't just grab something from the garage. The aggressive stuff for cars is not advised for such delicate jobs. Make sure it leaves no nasty residue either. I use "Tuner

600" but bought it in Europe, not sure if you can get it here in the US:

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For potmeters many audio professionals (not audiophools but the guys that actually run concerts) prefer "Fader Lube".

Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.

Contact cleaner?

Good Luck! Rich

ch.

=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0MikeK

What is your time worth? (Not talking about all the time it's been busted.) Can you just buy a new switch and install that?

Face it - Mechanical things wear out. And unfortunately, so do biological things... If it were me I'd probably just replace the switch, if it weren't too expensive or unobtainium.

Ok Larkin, I took your advice and stopped at Radio Shack and bought their Cleaner/Lubricant. I sprayed every switch and pot that I could get the spray tube to except for one I could not reach. That one was the delayed sweep position pot, 10 turn wire wound. I rotated everything many times, put it all back together and it works like new. I should have done this 3 years ago.. Hope it lasts! The delayed sweep is smooth so no worry for now. Thanks, MikeK

: :I gave mine a dose of "CO contact cleaner" and worked the switch back & :forth a heap of times, better but not perfect. : :Years ago there used to be stuff called "microscrub" for cleaning telecoms :relay contacts but I havent seen it anywhere for years. There was also slips :of pink paper looking material impregnated with solvents & a lubricant that :was used for cleaning instrument contacts but again I have not seen this in :catalogues for many years. Not much help hey! :

Microscrub was a 3M product if I recall correctly. It was boomed up as the wonder non-destructive contact cleaner for telecoms relays but in Australia its use was discontinued in the mid 70's due to the fact that it deposited small particles of debris on the contacts to insulate them. Telecom Aust thereafter recommended only using the traditional flat metal spring type contact burnishing tool. The metal blades could not contain abrasive materials such as carborundum or diamond dust either.

I've still got a couple in my tool collection.

Once upon a time,a long time ago, in the dim dark ages of TUBES, there were two fantastic contact cleaner made by General Cement, one a PD* based thin-looking red and (what i considered its companion) a PD* based yellow liquid; De-Oxide as a brand name comes to mind - do not ask which of the two that would be. A "newer" GC Electronics chemical would be their 10-630 Jif-Action contact cleaner: "contains silicone", "protects contacts", "won't harm plastics" "DANGER EXTREMELY FLAMMABLE. VAPOR HARMFUL. HARMFUL OR FATAL IF SWALLOWED". If you can get that,use very sparingly as it does a fantastic job; the only thing better was the De-Oxide which was superb on silver (TV tuner, remember those daze?) contracts. Now there are clear sprays for contact cleaners which do work - but not as well as those pre-flower power (germanium) cleaners...but better than a kick in the head.

  • PD = "Petroleum Distillate" in modern terms

I would be a bit wary of a product that claims "improved conductivity" as that could mean some rather nasty stuff that IS conductive and spreads like the plague over surfaces (like that "liquid silver" stuff, if i remember the name correctly). Use a cleaned plastic surface, spray some of the suspect stuff on, let dry and see if surface is conductive where you sprayed AND if there is any "junk creep".

From scratch, not knowing anything about this cleaner VS that other ?DeOxIt? stuff, i would hands-down prefer Tuner 600; no "improves conductivity" claim, and better yet "leaves NO residue" (my emphasis).

You know, the guy that tells lies about you before the meeting, so eveyone thinks you are a really clean (good) guy..

50 or more years of life for a switch seems typical...takes far more time to replace something that is OK but "dirty" than to clean the oxide/sulfide/dirt..

Appropriate...delayed cleaning for a delayed sweep pot...

tch.

=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 MikeK

tp://store.caig.com/s.nl/sc.2/category.188/.f

s

I'll second Deoxit. Caigs also has a lube for switches to apply after cleaning. It's a good company.

witch.

=A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 MikeK

nds

Caigs is good stuff. I've used it for years and probably will never use any other cleaner.

Nope.

That's on the mark. Originator was a Long Beach, CA mfr of telecom-related stuff, now in West L.A..

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*shrug*

Use it or don't, but I've never had any problems with it. I worked part time as a repair technician for one of the larger test equipment salvage companies, and the stuff repaired countless numbers of pieces that came across my bench. Now I do the same work out of my home, and it's still part of my arsenal. Lots of very knowledgeable folks in the Tek and Agilent Yahoo groups swear by it as well.

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