Too low of a filament voltage WOULD be detrimental to the tube life, BUT
reduced PLATE voltage while maintaining full filament voltage WILL
extend the tube's overall lifespan.
That's an area that I agree with Don completely!
It's the one place that variac use on start up of an older stored rig
can give you problems. The rectifiers are functionally out of whack.
Solid state "temps" would be wiser during that stage. Or even reform
caps with an old heath cap tester. It has multiple voltages to test
them with.
Bob - N0DGN
Donald Chester wrote:
A while back, you said something about running too little voltage on
the older
big jugs, like 833's, 250THs, 4-1000's, etc...
Of course, we know that running voltages that are too high will kill
the life
expectancy of the tube, by why is running too little voltage bad for
the tube,
if it's developing full emmission at a lower voltage?
I think low voltage would be ok as long as you are not exceeding the
current rating of the tube, starving the filament emission by running
too low filamrnt voltage, or exceeding the rated plate dissipation.
Don k4kyv
--
< Bob Bethman - N0DGN
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