[ARC5] 6k8 - 12k8?

[Kenneth G. Gordon]

On 16 Apr 2011 at 10:23, Dennis Monticelli wrote:

> I have another theory.  That may be a correctly built 12K8 with half
> the filament shorted upon itself.  Your typical filament is folded
> (often more than once) before it is inserted into the cathode sleeve. 
> When the insulating oxide coating on the filament breaks down or
> flakes off, it sometimes makes contact with the sleeve (heater to
> cathode leakage) but it can also make contact with its folded self.
> 
> Dennis AE6C

Hmmm....good point, and certainly not impossible. The trouble is, to prove 
this, one would have to dismantle the tube under a microscope, whereas we 
DO know that tubes have been mislabeled in the past.

Ken W7EKB