[ARC5] Faults around the 12A6.

[Leslie Smith]

  Hi Joel,  
  See below.

  73 de Les Smith
  vk2bcu at operamail.com


> 
> > You had mentioned that the AF Transformer may be bad once before.
>>  Is there one that can be exchanged with that transformer, a modern one, 
>> or should it have the original ARC-5 series transformer to replace it?
> 

I had a set that APPEARED to have a faulty output transformer.
In other words, I put a signal on the grid - nothing on the output.
I changed the 12A6 - no improvement.  A second time - no improvement.
I'm pointing a finger at the out-put transformer.
Replaced.  No change.  The problem?  A silver mica cap across the
primary of the output transformer.
Resistance across the cap?  240 ohms.  The problem was the dreaded
"silver migration" between the plates, or across the mica insulation.

So - look at more than the output "trannie".

Les



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