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Strange how many used valves measure NOS?

Finally fired up my valve tester.
All I can say is be very afraid.
Out of boxes & boxes of used valves bought on here
and ePain, most of them are crap.
I don't mind the odd chance buy being duff but some bought from here cost a fair amount and I'll be taking "measures as NOS" with the pinch of salt it deserves on ebay from now on.
There's either a lot of uncalibrated valve testers out there
or a lot of lying b------s.
I think it may be the case that some of these have been tested many moons ago by the original owners, marked up then used for a few years then the resellers think since it's marked 90/90,
it's still nos.
Bizarre, I have definite NOS 6SN7's that struggle to make 90/90.
Still it's fun to discover the occasional diamond amongst the rough.
Yes I will be getting the tester's calibration checked but having done dozens of valves and half a dozen different types, I can't see that it can be far out.
We live & learn.
simon74
simon74 OP
216 posts
 
Yip, I'm learning !
Strange thing is some tubes I would put as obviously unused,
perfect in every respect visually, don't measure worth a toss. Some respectable looking ones that measure way less than indicated by the seller actually sound fantastic.
Lots that measure as acceptable seem to measure well on the life test but I new to this so who knows.

I would have to agree people need to show a bit of restraint in encouraging silly prices.
I'm just happy I have a good stash for my Supratek
tbg
5,263 posts
 
When you were able to buy NOS tubes in any town, you would occasionally get a bad tube. Untested NOS tubes from anyone are a crap shoot. Probably strong not NOS tubes have much life left in them.

Since in my experience, there are no new tubes that reach the level of tubes manufactured 40 years ago, I have to live with this uncertainty.
kevziek
323 posts
 
Correct. I should have mentioned this in my prior comments on NOS tubes. Just like any unused tube, there will be rejects and those that have weak or unmatched triodes, shorts, etc.

Yet, people advertise untested NOS tubes, and get good bucks for them because they are in original boxes. I see it all the time. But the flip side, and more important, is the rampant misrepresentation of tubes as NOS. Used junk, cleaned up to deceive, given altered measurements to deceive. The author of this thread himself measured numerous supposedly NOS tubes he bought, and found they didn't measure anywhere near claims. Caveat emptor.
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