24 Feb
2009
24 Feb
'09
1:24 p.m.
Years ago, I had read a book about the Whirlwind
computer developed at MIT. ?In that book was the claim
that margining had been invented during that project,
the idea being to increase the voltage and make the
weak tubes fail so that overall reliability would be
improved after they were replaced.
I've wondered if that's really true or was the
technique in common practice and it just became
formallized at that time and entered into historical
lore.
The claim is not good. Controlled margining has been around for a long time.
One of the best ways to margin test a tube is to decrease certain
parameters, and see if performance dives. A big decrease can show that
the tube is just about pooped out.
--
Will