[Amps] Contacts Cleaner

[Bryan Swadener]

Joe:  In the TELCO industry, we learned switches become oxidized from  
"dry switching" (one reason for the 20mA loop current). 
 The FIRST thing to try is to run the switch back-and-forth several/many times. 
If there's any oxidation, the "wiping" action of the contacts should clean it off. 
If that doesn't work, look for crappy solder joint(s) or bent contacts. 
 
In any case, do NOT use anything abrasive (the microinches thin silver plating 
will be removed). If the switch needs to be replaced, Allied Electronics has 
Electroswitch pn D4G0205N (datasheet) in stock for $18.31. Or, you can use the 
used switch Lou W1QJ offered you on the other forum you posted this to... 
 
vy 73, 
Bryan WA7PRC 


      From: Joe <nss at mwt.net>
 To: Amps group <amps at contesting.com> 
 Sent: Tuesday, January 23, 2018 6:06 AM
 Subject: [Amps] Contacts Cleaner
  
I have been bringing an old SB-220 up from the grave with a 220 volt variac.

Ever soo slowly.? But one think I have noticed is the multi switch is 
very flakey,

it will read the hv but only with a lot of wiggling

what does everyone recommend as far as a cleaner and best way to clean it?

Joe WB9SBD