[Amps] Switching PS for filaments?

[Tom W8JI]

> It may be 1 in 1000 but if you are the 1 you might well 
> think the number is
> 1 in 1. After loosing the filament in a couple of 8877s 
> and a TH347 over the
> years, I have become one of the fanatics!


.....and you know the filament would NOT have failed anyway 
in that 1-in-1000 case WITH protection in that same tube 
because ......????

Sometimes, like it or not, things just fail because they 
have a manufacturing defect. That sometimes triggers us into 
finding a pathological cure.

That's certainly OK so long as we know we are leaping to 
conclusions. :-)

Of course it is a good idea to not use a transformer and 
wiring that can dump 100 amperes into a 10 amp filament, the 
question is what really caused the failure.

73 Tom