813 warm up time
A wrote:
Which means by simply lowering the lamp's applied voltage by 5% we
increase
its life by nearly 2 times!
Yes, and sometimes it is worth doing this. I'll bet that the long life
bulbs out there are made with a little more filament wire so the
temperature is maybe (also) 5% lower, too.
Which fits very nicely with the wartime conservation recommendations made
by some of the tube manufacturers.
Fine.
Now, the second part of the question is: does it matter?
If the filament life under normal operating voltages exceeds 20,000 hours,
than dropping 5% and gaining an additional 18,000 hours, is probably
not going to result in a noticeable improvement in life. Forever is
forever.
-Chuck Harris
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