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6sn7 NOS tubes with strange white sth on pins

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mad_z

Member
Joined 2002
Hello,

I have got NOS russian 6sn7 tubes that look to be ok - no scratches, stiff mounting with base etc, but on their pins there is a rigid-dry very difficult to remove white substance that covers especialy junctions with base - what is that? Are these tubes still good for use??

Pls, help:(
 
ashok

ashok

Member
Joined 2002
Maybe oxide deposit.

Hi Mad_z (?),
The white deposit might be some oxide or other chemical deposit. I have many NOS Russian 6SN7's and I have not come across this thought the pins are not 'shiny and clean'.
You could try mild acid like acetic acid ( vinegar ) . I am not sure if this will damage the pin but I think not as vinegar is also used with normal metal spoons in the kitchen. However don't leave it on too long and make sure that everything is washed well after application. Leave the tube in a place it can dry well before using it. You don't want it to crack open.
Remember you can also use fresh lemon juice - it contains acetic acid. Rub a piece of lemon on the pin !
You could apply scotch tape or insulation tape around the phenolic base and the glass tube. This will prevent any water entering that area. It might take a long time for any water to evaporate from there !

Boy - am I freaking out !!
Cheers.
 
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