[R-390] Gettering old tubes

[Jerry O. Stern]

I thought the original thread began about how reliable/good were NOS (really
old) tubes.  I have a neighbor who does estate and storage auctions looking
for NOS audio/amplifier tubes mainly 6L6 (metal), 6L6GC (glass) and EL34's.
He built different fixtures for these as well as for NOS 12AU7/AX7/AT7's.
He plugs in 10 at a time and he "cooks" them for about a week at rated
filament voltage and reduced plate voltage.  These tubes span from the 1940-
1970's.  His Sencor tester, which is supposedly very sensitive to gas, has
found fewer than 1 in 100 to have shorts or gas. A grossly gassy tube can
never be re-gettered.  I do him a favor and run a batch of 20 or so of the
power tubes every few weeks through my Hickock 539C where I match them for
current draw.  He sells them to the guitar tube amp folks and them love
them. 
I found this link where you can buy a very pricey version of his fixture.  

Does this really improve the tubes??  YMMV

http://www.maximatcher.com/maxiburn.html


73 Jerry
K1JOS
-----Original Message-----
From: r-390-bounces at mailman.qth.net [mailto:r-390-bounces at mailman.qth.net]
On Behalf Of 2002tii
Sent: Thursday, March 03, 2011 1:51 AM
To: R-390 at mailman.qth.net
Subject: Re: [R-390] Gettering old tubes

Jerry wrote:

>Those strange audio geeks love NOS tubes but they cook the tubes for
several
>days on filament only without grid or B+.  They swear the getter(s) do the
>job 90+% of the time on 50-70 year old tubes.

Just remember, they swear to lots of things -- most of which are 
unadulterated BS.

Bottom line, with receiving tubes a few days of any treatment that 
doesn't melt the glass can't do anything useful about gas.

Best regards,

Don


































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