[ARC5] A little off-topic: Metal tubes (eg 6SJ7) seem quite valuable ...

[Ben Hall]

On 9/15/2021 3:24 PM, Tom Lee wrote:
> My experience is the same as yours. I’ve opened several over the
> years, and I’ve never seen one that was simply a metal covering over
> an otherwise glass tube.
Greetings all,

Years ago I obtained a large quantity of assorted tubes - all just thrown into cardboard boxes - all of questionable provenance.  After sorting them out, I had about 30 metal octals that were rusty and unidentifiable.  I try not to waste anything, so I cut them all apart to salvage the octal bases.  (for what?  I don't know...but I will say I've made a few of them into test adapters, etc...)

Every single one had a glass seal between the octal base and the metal envelope, but in all of them, there was no further glass.  They were not glass tubes in metal sleeves; once past the glass seal, the metal envelope was what held the vacuum.  :)

Thanks much and 73,
ben, kd5byb