B7971 NOS or simply old

[Marcin]

There is an auction http://www.ebay.com/itm/290922533510 (not mine
auction) where yet again seller states that the tubes are NOS. This
auction tripped me to finally come over my embarrassment and ask:
Could somebody explain me how the discoloration around cathodes is
supposed to appear during the tube operation? I understand that the
common knowledge is that only used B7971 have it. The new ones should
have a uniform back-plate.
Marcin

[yen...@internode.on.net]

Here is an interesting one too:-

"Excellent Sylvania 6879 mini Dekatron display tubes. Made in USA. Beautiful mini Dekatrons! Very novel and good choice for many display applications.  These are perfect examples originally tested to work 100% as new."

Item number:  271211024665

Some very nice items for sale. Just a pity that the sales pitch sounds so audio-phool.

Other auctions use " New NOS" and also seems to use 'tests NOS' to be NOS. I posted examples before IIRC. 

 

John K. 

----- Original Message -----

From:

neoni...@googlegroups.com

To:

<neoni...@googlegroups.com>

Cc:

Sent:

Mon, 27 May 2013 15:22:32 +0200

Subject:

[neonixie-l] B7971 NOS or simply old

--
You received this message because you are subscribed to the Google Groups "neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+...@googlegroups.com.
To post to this group, send an email to neoni...@googlegroups.com.
To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/51A35E18.1070607%40gmail.com?hl=en-GB.
For more options, visit https://groups.google.com/groups/opt_out.

[jf...@my-deja.com]

On May 27, 6:22 am, Marcin <marcin.r.adam...@gmail.com> wrote:
> Could somebody explain me how the discoloration around cathodes is
> supposed to appear during the tube operation? I understand that the
> common knowledge is that only used B7971 have it. The new ones should
> have a uniform back-plate.
> Marcin

One the B7971s that I have broken, the back plates were white ceramic
with the black coating. I always assumed that the lightening was
caused by sputtering: some of the positive ions miss the cathode and
hit the back plates, eroding the black material. If the discoloration
came from the manufacturing process, like shadowing by the cathodes
during deposition, I would expect it to be more loaclied under the
wires.

[Nick]

I have never seen a guaranteed-no-ambiguity-absolutely-certain-NOS B7971. Its known that when the tubes were swapped out from Ultronics panels that the removed tubes were normally fine (never seen a failed B7971 either) and placed into the expanded polystyrene packing that the replacements came in.

The cynic in me says that the reason that the tubes have no markings is that they've been washed to make them really clean, but of course, I could be wrong...

At USD 175 per tube, they'd better be something special.... I've got quite a lot of these out in the field and in 15 years have never had one fail - my oldest clock with these is over 20 years old and all the tubes tick along nicely with no sign of aging.

Nick

[David Forbes]

Thanks for bringing that up. The only way to know a tube is new is to...
well... I don't know. A lack of discoloration on the insulator would be
a good sign.

The lack of markings is a big red flag. All factory tubes that pass
inspection are printed with their part number, to make them ready for sale.

The date code is less certain, as I have a pile of unused ITT 5870 tubes
with no date codes. When I bought a hundred of them from Richardson,
they got printed with a 2002 date code! Later, when I bought them out,
they shipped the tubes in the original bulk styro trays. How do I know
they're not used? Because they have long leads.

So, as usual, NOS is most likely to mean "Used tubes in the original
packing materials of their replacements from 40 years ago".

--
David Forbes, Tucson AZ

[Terry Kennedy]

On May 27, 9:22 am, Marcin <marcin.r.adam...@gmail.com> wrote:
> There is an auction http://www.ebay.com/itm/290922533510 (not mine
> auction) where yet again seller states that the tubes are NOS.

The seller does have the original packaging (36 tubes in a 6 x 6
styrofoam tray) and has exactly 36 tubes for sale. However, when these
tubes were new it was apparently common practice to take trays of
replacement tubes to the display site (a single LECTRASCAN frame had
48 tubes) and do bulk tube swaps.

The cleanliness of the tubes (and lack of any markings) also points to
these not being new. If they were new, they'd still be well over 40
years old and should have some dust on them). It appears that they
were recently cleaned.

And the seller wants quite a premium for these, says they were "fully
tested" but doesn't show ANY lit, and sells them "As is, no returns or
exchanges".

The seller has good feedback, but almost all of it is as a buyer, not
a seller (2,646 / 127) and the most recent feedback as a seller is
from early 2010.

On the other hand, most of their recent feedback as a buyer is for
Nixie / VFD stuff. Therefore, you'd think they would know how
important it is to show a lit Nixie if selling "as is".

[Nick]

I have some boxes of 200 NL 5440As from Richardson with no markings at all - nada.

Mind you, the boxes they came in are marked!

My guess is that these were intended to be "white labelled", i.e. marked just prior to shipment with the branding the purchaser requested...

Nick

[Dekatron42]

There was (is?) a German seller who sold B-7971 in identical styrofoam boxes a few years ago. His came from unopened cardboard boxes which looked to be original and those tubes were as clean as these and they did not have any markings on them either. That seller was (is?) a respected seller of old equipment and his B-7971 were sold quickly. Unfortunately I do not remember the seller alias nor do I know any of his auctions right now (if he has any), but if anyone knows who it is maybe contacting him and comparing with this seller would be a good idea.

 

Why not also ask this seller more about these tubes?

 

/Martin

[chuck richards]

Wow!! At USD 175 per tube, that's a significant
return on an investment made years ago, should one ever
want to sell any!

I bought most of my stash back when they were around
USD 11 to 15.

Heck, that's better than the stock market!!!

Chuck

>>--
>>You received this message because you are subscribed to the Google
>Groups "neonixie-l" group.
>>To unsubscribe from this group and stop receiving emails from it,
>send an email to neonixie-l+...@googlegroups.com.
>>To post to this group, send an email to neoni...@googlegroups.com.
>>To view this discussion on the web, visit

>https://groups.google.com/d/msgid/neonixie-l/74ca8f87-9bae-44bb-bcb1-
>8358115673cf%40googlegroups.com?hl=en-GB.

>>For more options, visit https://groups.google.com/groups/opt_out.
>>
>>
>>

$4.95/mo. National Dialup, Anti-Spam, Anti-Virus, 5mb personal web space. 5x faster dialup for only $9.95/mo. No contracts, No fees, No Kidding! See http://www.All2Easy.net for more details!

[Marcin Adamski]

Yes, that is the explanation I also came to. But is it possible? I
believe battered Nixie show black deposit rather than bleaching around
the cathodes.
Isn't it possible that the back plates were just made that way? Have
anybody ever seen a B7971 with completely black back plate?
Marcin

[Mich...@aol.com]

I have seen/handled over a thousand of these.  I have not seen a completely black plate.

 

Michail

[Terry Kennedy]

Do you ever get the feeling you're being watched? 8-}

The seller has updated the listing with a new title which has "looks
new tubes" at the end. There are also pictures of lit tubes, and a
number of other photos and new captions.

The seller also says that dark spots on the back of the tube may
indicate new (their last photograph). I just took a quick look at 6
tubes here (the back of a MOD-SIX) and 4 have similar spots while 2
don't. Of those, I have 4 tubes which represent 3 consecutive lots
(lots C124, C125, C126 from the 6440 date code) where two have the
dots (one C124 and one C125) and the other 2 (the other C124 and a
C126) don't.

Given the known huge variation in these tubes over their (relatively
short) production run, such as the "space antenna" variant, red print
vs. white print, and C line vs. D line (at a minimum), I don't know
that ANY physical characteristic could clearly identify this type as
new, other than something like non-evacuated tubes with unsealed
stems. There's also the issue with variations in the angle of the
underscore, which vary all over the place, even on tubes from a single
lot. I also don't know why the factory would store completed, unmarked
tubes in space-wasting foam shipping trays rather than in a simple
divider box (such as IN-18's ship in).

The seller does say that he didn't clean the tubes and that they're
brighter than the used tubes he has. Buyers need to decide if that is
worth the price premium and the "as-is, no returns" condition.

[Jeff Thomas]

The seller of these tubes is Patrick, and was a member of the old yahoo neonixie-L (user=arcpat1 from as early as '04), although I don't know if he's posted to the replacement google list.

Yeah, IMHO these B7971's are just washed-and-recycled tubes in the stock styro carrier. It really does not matter as long as they're sold with a guarantee of all segments being functional.
$175 is certainly a lofty goal for as-is. He may sell some if others squatting on tubes don't jump at the opportunity to undercut his pricing.

Regards, Jeff

[Marcin]

Among members here we have seen thousands of B7971 and as Michail wrote:
'I have not seen a completely black plate'. Should it be then assumed
that we can not use whitening of the back-plate behind segments as a
clear sign that the tube was used? Sorry for pushing this back over and
over. I just want to deal with this 'myth'. Either way is fine with me. ;)

[Nick]

Yes - to clarify he was a bona fide member of neonixie-l (don't think he is any more) and I too have bought from him in the past - he seems to be a straight guy.

When tubes are lit after a while in storage they often behave slightly differently until "burnt in" - could be just that effect.

The "clean" tubes I was referring to about from RIchardson - NL 5440As - have no markings at all - they're the ones that would have been "white labelled".

The interesting thing about 7971s is that not that many were made (anyone got actual numbers, or is that also here-say?) yet there are many variants, all of which appear to be totally reliable/built like tanks - why mess with something that obviously works so well>

Has anyone ever had one fail in operation (assuming it was being run within spec)?

Nick 

[NoCampersFluffy]

From my correspondence with the seller via Ebay he displays sincerity and recently updated his listing I suspect to reflect his own uncertainty as to the "new old stock" vs "new from the package" status of these tubes.  His update to his listing mirrored our ebay conversation, which in my experience is a good indicator of people's good intent.  The suspect ones don't reply or are not interested in a genuine conversation about the items in question.  The additional photo that was added showing a lit tube, does add some credence to the claim that all the tubes are tested and work.  I have bought tubes that when delivered do not work, and a statement in the listing that the tube is tested and works will at least satisfy the Ebay commissars should a tube actually prove faulty and you need a refund.  Like others, I view the tubes as used, in that they have what we have all taken from the example of our own tubes, to be spluttering around the cathodes.  I have no idea what a NOS B7971 would be "worth" as I have never seen one, but we all pay attention to the price of traded tubes, as I suspect most of us are holding quantities of tubes for various projects if not investment.  I wished him luck with his auction, will personally not be buying b7971s at those prices and am in no way associated with the auction in case anyone is interested.  

[jf...@my-deja.com]

On May 28, 2:13 am, Nick <n...@desmith.net> wrote:
> Has anyone ever had one fail in operation (assuming it was being run within
> spec)?
>
> Nick

Not yet. As a reminder, I built three 6-digit clocks that have been
running almost 24/7 since the mid 1970s (one down briefly for a bad
electrolytic). I plan to use the spares to fund my retirement.

[MichaelB]

Jeff is correct. I have 1st hand knowledge of where these came from. They were sourced from Richardson before their supply dried up, and at reasonable prices... very reasonable prices! They were fully functional at that time.