Re: [neonixie-l] One reason for blue dots in Nixie tubes found - anode mesh n...

[Mich...@aol.com]

Now I have to check all my blue tubes.

 

I have decided I liked the blue and have 2 clocks only with blue dots.  IN-18 tubes.  What is strange is that I only get them with digit #1.  maybe because of the least amount of surface in the digit?

 

When asked, I just say they are spirits in the clock.  heh.  (Sell for more that the plane old IN-18 clocks :)

 

Michail

 

[Dekatron42]

Hi Michael,

 

It would be very welcome if you could write what you find here as this is an intriguing problem.

 

I haven't bought any IN-18 as they do not fascinate me and I have never had any need for them, but I have bought quite a few of the end view types like z5600m / z560m which shows the same behaviour. At first I wasn't aware of these being marked with "ungültig" or "unverkäuflich" but later I learned that these were nixies that were not meant for sale or possibly prototypes or those checked but not deemed good enough for sale. There are actually quite a few of these sold on eBay these days where you can see the purple print on the boxes saying "ungültig" (just do a search today and you'll find them) but some sellers hide these prints in the photos so you won't see it before you buy them. Nixies from the same seller without the "ungültig" print works just as they should.

 

Another effect I have seen on these "ungültig" z5600m nixies that show the blue spots is that they quite easily light up around the wires connecting the figure to the pins on the socket - just as this zm1042 with the disconnected anode mesh does. I have seen this on perfectly normal nixies too but those have had a lot of cathode posioning, but after that has been worked away they do not glow on the connecting wires whereas the "ungültig" ones still glow on the connecting wires no matter what I do with them. These might possibly have the same kind of open circuit anode connection but I have not been able to spot it in them as I did in this ZM1042.

 

Martin

[kay486]

Well, i asked about the ungultig marks here before, and yea, i have one Z5600M that has blue spots almost on all digits, but i got another three tubes which i bough together with the previous one, so they seem to be from the same lot, that are perfectly fine.
I also got two dekatrons Z562S that came from ungultig boxes, but unfortunately i can not test them (all i know is that they are not leaked) could there be a problem with these?
Also about the glowing leads, i found out that it can happen with Z568M / Z5680M when you fire them at lower voltages that the recomended ones (im talking about NIB tubes) but they are absolutely fine at higher voltages though.