Need a new 109(?)

[buddhasummer]

Boredom is the devils playground.

 

[buddhasummer]

Or a place of inspiration.

 

[Eric Sedletzky]

Go incognito and take an OW class with that reg pretending you don’t know a thing and see the reaction from the instructor, lol!

 

[Aloha Joe]

You should have seen my OW instructors face when I told her I serviced my own reg.

 

[RMcIntosh]

Is there a way to tell the manufacture date on a 109. My serial number is 7508289

 

[Couv]

Is there a way to tell the manufacture date on a 109. My serial number is 7508289

Don't quote me on this as SP changed their numbering system more often than I change my socks. However, I think your regulator was the 289th made in August of 1975.

 

[Open Ocean Diver]

My two:
BA SN 5907469
108 SN 481669

must be using a different numbering system.

 

[Aloha Joe]

This one looks like it was made in 2019 =D

(This is replacing a 190 on my lightweight reg set and is unrelated to my OP. It came today and I just had to show it off!)

 

[Couv]

I've got a help call out to someone who researched the SP serial number maze. Let's see what he turns up.

 

[Couv]

Update:

My source was not absolutely sure about the numbering system, but here are a few clues.
A s/n with 6, 7, or 10 numbers: The first number indicates the production year-so one has to have an idea of which decade his regulator was produced in. So in the examples given by @Open Ocean Diver:
BA SN 5907469 <--probably 1985 unless it is a very late model which might make it 1995 (does it have a satin finish?)
108 SN 481669 <--probably 1974

Eight digits: the first 3 digits indicate the Julian date*, Digits 4-5 indicate the year, 6-8 indicate the production number.

9 digits? I do not have any information on those.

*Julian date: the day number of the year. E.g. today 09 Aug 20 is the 222nd day of the year)