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Cleaning switch contacts on Scope

A

amdx

Jan 1, 1970
0
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!
 
J

JW

Jan 1, 1970
0
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!

Assuming that the problem is dirty and/or oxidized contacts, Deoxit D5.
http://store.caig.com/s.nl/sc.2/category.188/.f

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

Joerg

Jan 1, 1970
0
John said:
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.

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:

http://www.dact.com/Tuner_600_data_sheet.pdf

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

Rich Grise

Jan 1, 1970
0
amdx said:
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!

Contact cleaner?

Good Luck!
Rich
 
A

amdx

Jan 1, 1970
0
John Larkin said:
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
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
 
R

Ross Herbert

Jan 1, 1970
0
:
::>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
:eek:f 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.
 
J

JW

Jan 1, 1970
0
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".

*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.
 
A

amdx

Jan 1, 1970
0
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!

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?

The scope is probably 30 years old. If I could get a switch, it
would cost more than the scope is worth. The switch assembly
is about 5" long, has 4 wafer sections and has a pot. on the end.
I would buy a new scope before I would replace the switch.
I cleaned it, that solved the problem.
Not sure I understand the "time worth" question, 15 minutes
to clean the switches, hours to replace the switch.
Ah.. maybe this helps, it is a scope for hobby use.
MikeK
 
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