MBU-12 / 14 date stamps uncoded

[stingray77]

I always wondered how to uncode the manufacturing stamp on MBU oxygen masks - I found so many varieties that I just couldn't come up with a solution to uncode them myself...

 

Below is an example how these stamps look like:

 

there's an inner circle divided into three segments showing three consecutive years (my example 83-84-85)

the outer circle is divided into 4 segments per year / 12 segments overall with dots highlighting these segments - or not (my example: dots starting 84 and going up to 3/85 - but no dots in 83!? We'll come to that later)

[stingray77]

Okay, looks straightforward - inner circle denotes the year, the outer one the quarter of production in this year... But - hey, how come no dots in 83 in my above example and dots only starting at 1984 but not 1983?

 

And how about this one:

88-89-90 and a dot missing in 4/89???

[stingray77]

Or this one:

83-84-85 - but NO DOTS AT ALL???

(sorry for the poor quality of the photo - believe me: no dots!)

[stingray77]

Might it be that the dots did not go for quarters but months of one year during these three year-periods?

Anyway I did not find a way to decipher myself...

 

...So, I checked back with Gentex directly who were manufacturing part of the MBU-production.

 

Here's their quick (and kind) answer:

"...our “rosette” identifies a 3-year manufacturing period divided by the four quarters of the year.
From what we can tell, there was no production in 1983.
Additionally, you may also see a quarter where there was no production – so you might see a dot in first quarter, nothing in second quarter, and a dot in third quarter."

 

Cool - this answered my question. So my MBU posted on top was a production of 3rd quarter 85. (No production in 83 - so no dots before 84.)

 

And the second is a 4th quarter of 90 (there's the latest dot) with no production in 4/89 (empty).

 

BUT: my mask with no dots at all was a mystery even to the Gentex-staff themselves - that should not have happened and this still remains an open question.....

 

Hope this info is of help and please feel free to add your information if you have any.

 

[BlueBookGuy]

Well it looks like you could pretty well be owner of a 'one-of-a-kind' MBU-12 mask? Never say never in this so complicated fiel of collecting.. your research is indeed an in-depth one and worthy of finding the right answer.

Some guys in this Forum surely will appreciate such small and often overlooked (yet interesting) details like those just treated, and perhaps give any helps - personally I do not have the imput to go after them, nor the competency.

[stingray77]

Well, doesn't it come as a natural result: first you collect all the gear, then you get interested in putting it together period-correctly? It least it was like this in my case (and still working on it...) Just the next stage...

 

Haha, yes, possibly my no-dots-mask is a one of a kind... Who knows...

[BlueBookGuy]

yes it's true, the same has happened with some of my guys as for it comes to (for example) the oxygen-related gear but being meant as a secondary, airplane-to-pilot interface.

 

In one specific instance - the Russian high-altitude interceptor pilot - I happened so fascinated by that weird and so much different oxy. gear and related things from the usual Western ones we're used to see, I spent almost two years in researching where possible in first-hand documents by the Zvezda firm and engineer S. Umanskiy (the main inventor behind the KKO-5 integrated system).

Most of material I eventually found and got - a strange-looking, surprising solutions design.

[stingray77]

Yes, very interesting and great looking (evaluating from the pictures you shared with me)... And I doubt that for "your kind of stuff" there are forums like this one, making available to the public SUCH a wealth of information.

 

And after a while it gets part of the collecting-fun digging out information and details like this one in my thread, right?

Hope that over the time this might be of value to others as well...