Hi Gang,
I have a pair of Alpha amps with 3cx800's in them. I like the tube/amps
and the gain they have. Accordingly, I came across some spares (NIB Eimac)
which I purchased, which as you know are rather expensive nowadays.
What is the general consensus for the best storage strategy for preserving
the life of the spares?
Every once and a while, I come across something that indicates that the
external anode ceramic/metal tubes likes these do not have as good a seal
as is possible on the traditional glass envelope tubes.
If this is correct, are we talking about limited shelf life of unused
spares? Or is this just BS?
For if they are limited life, and given the extraordinary life of them if
properly
cared for in amateur service, why then buy any spares (assuming one can
still get them)?
Hell, I may not need 'em for 10 years or more !!
Since they are quite expensive, I am willing to do a little preventative
maintenance if that is in order given it may be many years before they are
needed. Therefore, what is best practice for preserving spares so they
will
still be good as new (which they are now) and ready to rock & roll when I
need them?
Some stuff I have read suggested that leaving them sealed up in a box
is NOT the way to get maximum life out of them, but go no further to help.
I have no idea what to believe, but I'm sure there are some resident experts
on here how know a whole lot more about 'em than I. OTOH, I guess I could
go
out and buy some anti-aging miracle creams from one of those late night
info-commercials, rub
it all over 'em, and hope for the best too (Cosmoline? :-) ).. But I would
think there is a
better approach.
A few things to start the discussion thread -
Should I just leave them in the closet, or should they be exercised
periodically
in some manner?
And if so, would it suffice to create a little jig with filament xfmr,
socket, and proper cooling, or would B+ need to be applied to be helpful?
Any sequencing needed? Like - filament first for N hours, followed by B+?
Ramp up the B+ & current
limit for glitches?
How frequently should this be done?
Position in storage make any diff? Vert/horiz ??
Anything else/other???
I'd prefer not to actually rotate them in/out of the amps if I can help it.
Are there any differences between these things for external anode vs.
traditional glass bottles?
I know a little bit about getters/gassing and such, but really only via
reading
on the web.
Oh oracles of the Order of the Valves out there. pse edumacate me with ur
wisdom
-bob
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