[Milsurplus] BC-348's and 6AC7s...

[Kenneth G. Gordon]

> You can't substitute just one 6AC7 for a 6SK7 or 6SG7 in either the BC-224 or
> BC-348. The filament current of the 6AC7 is 450 MA whereas for the other two it
> is 300 MA. You'll end up with too little filament voltage across the 6AC7 and
> too much across the other or others.

Ah, yes. I had forgotten that the filaments in a BC-348 were connected 
in a series-parallel arrangement so that it can accept 24 V for filaments.

Ken W7EKB