Author Topic: How to clean contacts of a precision resistor decade (0.01%)?  (Read 6011 times)

0 Members and 1 Guest are viewing this topic.

Offline carl_lab

  • Frequent Contributor
  • **
  • Posts: 418
  • Country: de
Can somebody give me advice how to clean contacts of a precision resistor decade, without doing any harm to it?
I used a dry cellulose swab wiping the contact, but resistance is still unstable (rising slowly)...

I'm not quite sure, how to relubricate contacts (I'm not a believer to magic contact cleaner chemistry voodoo). There's still enough grease on the remaining contacts, so I hope it will dispense to all contacts some time later in normal usage.

Root problem still remains.
Some wiggling the dial helps temporarily, but some minutes later, resistance is increasing again.


« Last Edit: March 29, 2017, 06:14:26 am by carl_lab »
 

Online BU508A

  • Super Contributor
  • ***
  • Posts: 2332
  • Country: de
  • Per aspera ad astra
Re: How to clean contacts of a precision resistor decade (0.01%)?
« Reply #1 on: March 28, 2017, 09:50:52 am »
“Chaos is found in greatest abundance wherever order is being sought. It always defeats order, because it is better organized.”            - Terry Pratchett -
 

Offline VK5RC

  • Supporter
  • ****
  • Posts: 2466
  • Country: au
Re: How to clean contacts of a precision resistor decade (0.01%)?
« Reply #2 on: March 28, 2017, 10:21:01 am »
Cleaning  wafer switches in an old Tek scope I used IPA on foam tipped swabs (no fluff from the cotton swab) , firstly on the common contact area, then the actual moving contact till a clean swab returned, Both sides. I then used a swab lightly soaked in deoxit as a replacement lubricant - but a decade resistor box is a lot more fussy.
In wafer switches I didn't try to get between the fixed contact and the moving piece as I figured I would do more damage. (I have used heavy paper to clean between relay contacts with success.) 
If I recall correctly,  Shariar used quite a bit of deoxit - I didn't use nearly that much and applied it just to the contact areas.
Rob  VK5RC
Whoah! Watch where that landed we might need it later.
 

Online alm

  • Super Contributor
  • ***
  • Posts: 1307
  • Country: 00
Re: How to clean contacts of a precision resistor decade (0.01%)?
« Reply #3 on: March 28, 2017, 10:26:59 am »
Caig recommends that critical, low current connections (which in my opinion includes decade resistor switches) be finished with Deoxit Gold G after cleaning with Deoxit D (or any other cleaning method that removes corrosion). If the contacts are not visibly dirty, I just spray a little G5 on them and rotate the switches a couple of times.
 

Offline carl_lab

  • Frequent Contributor
  • **
  • Posts: 418
  • Country: de
Re: How to clean contacts of a precision resistor decade (0.01%)?
« Reply #4 on: March 28, 2017, 12:13:28 pm »
Deoxit is not very common in Germany, difficult to find...
 

Online BU508A

  • Super Contributor
  • ***
  • Posts: 2332
  • Country: de
  • Per aspera ad astra
Re: How to clean contacts of a precision resistor decade (0.01%)?
« Reply #5 on: March 28, 2017, 12:17:08 pm »
You can find it on Amazon:

DeoxIT D100S-2
https://www.amazon.de/dp/B0014F110I

Deoxit DeoxIT D5S-6:
https://www.amazon.de/dp/B0002BBV4G
“Chaos is found in greatest abundance wherever order is being sought. It always defeats order, because it is better organized.”            - Terry Pratchett -
 

Offline carl_lab

  • Frequent Contributor
  • **
  • Posts: 418
  • Country: de
Re: How to clean contacts of a precision resistor decade (0.01%)?
« Reply #6 on: March 28, 2017, 12:20:10 pm »
Yes, I've seen the offer on amazon, but we cannot buy from amazon (because of our business guidelines... :palm: )
« Last Edit: March 28, 2017, 07:47:04 pm by carl_lab »
 

Offline Kjelt

  • Super Contributor
  • ***
  • Posts: 5942
  • Country: nl
Re: How to clean contacts of a precision resistor decade (0.01%)?
« Reply #7 on: March 28, 2017, 12:24:50 pm »
There must be some replacement from Kontakt Chemie, I would sent then an email asking what they have to offer. I know they have multiple cleaners each for their own application.
 

Online BU508A

  • Super Contributor
  • ***
  • Posts: 2332
  • Country: de
  • Per aspera ad astra
Re: How to clean contacts of a precision resistor decade (0.01%)?
« Reply #8 on: March 28, 2017, 12:28:45 pm »
Yes, I've seen the offer on amazon, but we cannot buy from anazon (because of our busyness guidelines... :palm: )

 :palm:

Probably this shop is accepted by your company's business guidelines:
http://www.micro-tools.de/Kontaktreiniger-oxid/
“Chaos is found in greatest abundance wherever order is being sought. It always defeats order, because it is better organized.”            - Terry Pratchett -
 

Online BU508A

  • Super Contributor
  • ***
  • Posts: 2332
  • Country: de
  • Per aspera ad astra
Re: How to clean contacts of a precision resistor decade (0.01%)?
« Reply #9 on: March 28, 2017, 12:30:46 pm »
There must be some replacement from Kontakt Chemie, I would sent then an email asking what they have to offer. I know they have multiple cleaners each for their own application.

IIRC the volt-nuts recommend Deoxit from CAIG. Not sure, if Kontakt Chemie (I know them well) achieves the same performance.
“Chaos is found in greatest abundance wherever order is being sought. It always defeats order, because it is better organized.”            - Terry Pratchett -
 

Offline carl_lab

  • Frequent Contributor
  • **
  • Posts: 418
  • Country: de
Re: How to clean contacts of a precision resistor decade (0.01%)?
« Reply #10 on: March 28, 2017, 07:30:57 pm »
I know Kontakt-Chemie well, but I'm not longer a fan of Kontakt-Chemie since the infamous "Kontakt 60" disaster many years ago.
« Last Edit: October 19, 2017, 07:29:57 am by carl_lab »
 

Offline Kjelt

  • Super Contributor
  • ***
  • Posts: 5942
  • Country: nl
Re: How to clean contacts of a precision resistor decade (0.01%)?
« Reply #11 on: March 28, 2017, 07:39:29 pm »
I know Kontakt-Chemie well, but I'm not longer a fan of Kontakt-Chemie since the infamous "Kontakt 60" desaster many years ago.
  :-// what was that?
 

Offline mcinque

  • Supporter
  • ****
  • Posts: 1048
  • Country: it
  • I know that I know nothing
Re: How to clean contacts of a precision resistor decade (0.01%)?
« Reply #12 on: March 28, 2017, 07:40:05 pm »
since the infamous "Kontakt 60" desaster many years ago.
What disaster?
 

Offline carl_lab

  • Frequent Contributor
  • **
  • Posts: 418
  • Country: de
Re: How to clean contacts of a precision resistor decade (0.01%)?
« Reply #13 on: March 28, 2017, 08:01:14 pm »
Kontakt-60 was very aggressive, and if not washed out carefully after application, contacts were destroyed.
Even the original metal can was destroyed by pitting corrosion (that's my personal experience, confirmed by some colleagues).
Not exactly the magic agent I want to remain in my precision instruments...
http://www.hifi-forum.de/viewthread-84-1094.html

https://www.amazon.de/CRC-Kontakt-Chemie-Kontaktspray-100ml/dp/B001CRC22Y
"Ein Nachteil:
Im Laufe von vielen Jahren (>15) wurde meine erste Dose von innen her undicht, und der Inhalt verteilte
sich immer mehr im Aufbewahrungskarton. Die Dose rostete von innen her durch. Wahrscheinlich haben die
z.T. aggressiven Inhaltsstoffe das Metall zum korrodieren gebracht."

What about "Oszillin T6" ?
http://teslanol.ch/teslanol-produkte-uebersicht.html?id=5
https://www.elv.de/teslanol-kontakt-tuner-spray-200-ml.html
« Last Edit: March 28, 2017, 09:11:18 pm by carl_lab »
 
The following users thanked this post: Kjelt

Online Vgkid

  • Super Contributor
  • ***
  • Posts: 2598
  • Country: us
Re: How to clean contacts of a precision resistor decade (0.01%)?
« Reply #14 on: March 28, 2017, 08:46:48 pm »
What is the decade(model/manufacturer)
Post pics of the switches. That will help in the determination of the course of action.
If you own any North Hills Electronics gear, message me. L&N Fan
 

Offline carl_lab

  • Frequent Contributor
  • **
  • Posts: 418
  • Country: de
Re: How to clean contacts of a precision resistor decade (0.01%)?
« Reply #15 on: March 28, 2017, 08:51:20 pm »
It's a Burster 1422:



I can post photos of the switches tomorrow.

« Last Edit: March 28, 2017, 10:48:20 pm by carl_lab »
 

Offline babysitter

  • Frequent Contributor
  • **
  • Posts: 852
  • Country: de
  • pushing silicon at work
Re: How to clean contacts of a precision resistor decade (0.01%)?
« Reply #16 on: March 28, 2017, 10:02:23 pm »
Hier als Datenpunkt: Ein zufriedener Nutzer von Teslanol Oszillin. Solltest Du im RheinMainGebiet sitzen kannst Du dir einen oder Spritzer abholen ohne ganze Flasche zu kaufen!

BTW: Das Kontakt 60 kann man zum _reinigen_ verwenden, wenn man es hinterher gut auswäscht.
I'm not a feature, I'm a bug! ARC DG3HDA
 

Online Vgkid

  • Super Contributor
  • ***
  • Posts: 2598
  • Country: us
Re: How to clean contacts of a precision resistor decade (0.01%)?
« Reply #17 on: March 29, 2017, 07:00:22 am »
It's a Burster 1422:
I can post photos of the switches tomorrow.
I look forward to it. Burster makes some high quality resistors.
If you own any North Hills Electronics gear, message me. L&N Fan
 

Online BU508A

  • Super Contributor
  • ***
  • Posts: 2332
  • Country: de
  • Per aspera ad astra
Re: How to clean contacts of a precision resistor decade (0.01%)?
« Reply #18 on: March 29, 2017, 10:01:50 am »
Here you can find a .pdf of the Burster 1422:

http://www.physicomcorp.com/doc_series/1422_Ser_Ovr.pdf

Nice gear, btw.  :-+
“Chaos is found in greatest abundance wherever order is being sought. It always defeats order, because it is better organized.”            - Terry Pratchett -
 

Offline carl_lab

  • Frequent Contributor
  • **
  • Posts: 418
  • Country: de
Re: How to clean contacts of a precision resistor decade (0.01%)?
« Reply #19 on: March 29, 2017, 10:07:53 am »
New photos...
 

Offline carl_lab

  • Frequent Contributor
  • **
  • Posts: 418
  • Country: de
Re: How to clean contacts of a precision resistor decade (0.01%)?
« Reply #20 on: March 29, 2017, 10:09:00 am »
.
 

Offline carl_lab

  • Frequent Contributor
  • **
  • Posts: 418
  • Country: de
Re: How to clean contacts of a precision resistor decade (0.01%)?
« Reply #21 on: March 29, 2017, 10:23:45 am »
..
 

Offline carl_lab

  • Frequent Contributor
  • **
  • Posts: 418
  • Country: de
Re: How to clean contacts of a precision resistor decade (0.01%)?
« Reply #22 on: March 29, 2017, 10:24:57 am »
...
 

Offline carl_lab

  • Frequent Contributor
  • **
  • Posts: 418
  • Country: de
Re: How to clean contacts of a precision resistor decade (0.01%)?
« Reply #23 on: March 29, 2017, 11:43:10 am »
Here you can find a .pdf of the Burster 1422:

http://www.physicomcorp.com/doc_series/1422_Ser_Ovr.pdf

Nice gear, btw.  :-+

Thank you!

... Ein zufriedener Nutzer von Teslanol Oszillin. Solltest Du im RheinMainGebiet sitzen...

You have mail! (PM)
« Last Edit: March 29, 2017, 12:02:29 pm by carl_lab »
 

Offline Kjelt

  • Super Contributor
  • ***
  • Posts: 5942
  • Country: nl
Re: How to clean contacts of a precision resistor decade (0.01%)?
« Reply #24 on: March 29, 2017, 03:34:40 pm »
Kontakt-60 was very aggressive, and if not washed out carefully after application, contacts were destroyed.
Even the original metal can was destroyed by pitting corrosion (that's my personal experience, confirmed by some colleagues).
Not exactly the magic agent I want to remain in my precision instruments...
:( Just checked and  :o
Darn I bought this can I think two or three years ago, what a mess.
But indeed it needs to be washed with WL that is standard practice.
BTW: I got the same problem two years ago with a can of videohead cleaner, but that took ten years to rost through and is not corrosive at all.
Any bit of moisture inside can start the process.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf