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.
Learn from your mistakes and dont buy valves from sellers without a money back policy. And you must test the valves yourself also.

Most NOS valves naturally cost more $$ but at least most of the time you know axactly what you are getting.

When it's too good to be true! Just stay away.

Post removed 
A lot has to do in the wording/meaning of NOS. Some newbies, or some which are playing dumb to rip people off, don't understand that NOS, means NEW old stock, ie, BRAND NEW, like found them in a military wherehouse, in storage.

Do used Vintage tubes test like a new tube? Often yes, but for the prices some people sell/get for their tubes, especially here, they should be virginally new.
I have out the hard way,there are only a few honest tube sellers out their.Twio that come to mind are Jim Mcshane and Kevin Deal.There are a few others,Mcshane offers money back,deal test the hell out of the tubes and burns them in.There is only a few who test them like Kevin but you pay the price.
Maybe I have been lucky but many tubes I buy as "used" actually test like new. I have only once gotten a dud - a 6AB4 I bought on ebay. I disregard the NOS label until I test them myself.
I recall reading (I think) that many tubes will test in the new range even though they are used. But at some point test wise they drop off the table (not a smooth curve between new and used). Don't hold me too it though.
Tested more today and the tester died - solid state here we come! Only joking.
Strangely some definitely nos tubes I have test mediocre but sound fine and some that test brilliant are noisy as hell in the amp.
Will have to sort and calibrate the tester as it's strangely addictive - like the lottery I suppose.
I must admit to having had :-(visons of sparks, smoke and spectacular explosions but it was good as gold whilst it worked.
Strangely enough there are still places here in the UK that sell good valves at reasonable prices, just a shame that I prefer US of A valves over the soupy examples of Brimars and Mullards I have tried.
If I ever manage to get my dream amps (lots), I'll be a paranoid wreck given the price of replacement tubes.
Post removed 
Finally someone has had the guts to tell it like it is. Yes, there are a number of greedy tube sellers on this site that are less than scrupulous, yet have "perfect" feedback because foolish audiophiles believe the lies and misrepresentations. These same audiophiles don't know the difference, and are blissfully ignorant that they have purchased used, poorly matched, and mediocre-sounding tubes.
These same sellers go to hamfests and flea markets, picking up old, used tubes, and then pawning them off as NOS or near NOS on the innocent.

Beware of just following feedback on these tube sellers for these very reasons.

Jim McShane and Kevin Deal have very good reputations, as does Andy Bowman @ Vintage Tube Services. Some of the prices are unjustifiable, in my mind, but silly audiophiles have driven this madness this far, simply by being willing to pay these exorbitant prices.

NOS = New. A new tube will look new, 90% of the time. If you know how to look at it, you can tell JUST from that. The lettering, the base, the pins, the flashing.

I also have been told that tubes with many hours on them can measure "NOS", but their life is past the 50% mark. Eventually, a decline in the reading will plummet.

Buyer beware.
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
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.
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.