The Russian Mosin Nagant Forum

Ok I need some help from the tinkerers, antique gurus, older generation, etc. What the hell is this type of bulb assembly called? And where can I find something like this nowadays?

I got power to the sextant, not bad for a 74 year old navigational instrument. I have everything working except for the Bubble Chamber which needs overhauled and this one bulb that needs replaced.

Anyways there is the one bulb that is out, on the spare one the threads on the base are messed up and it won't screw in all the way. Don't want to force it for fear of stripping the threads on the sextant, or breaking the bulb assembly.

Didn't notice there was markings on the bulb base until I cropped the pictures for posting, then I had to take a magnifying glass to it to read it. I did a google search for those markings and came up blank, other than an Edison connection. Markings are as follows:

3V 323 MAZDA has a larger/longer glass bulb, this one the threads are messed up on.
3V 322 MAZDA has a smaller/shorter glass bulb, this one installs in the sextant.

Both bulbs are the same in size per se but 323 has a longer glass area and shorter base, the 322 has a shorter glass area but a longer base. There are a total of 3 bulbs on the sextant 1 like the one shown, and two that are different than shown but are identical to each other. The sextant comes with 2 spares of the one, and one spare of this one. So any help or information I can get I would be grateful as hell!

Mike, doesn't that bulb come out of the holder? Either threaded or twist-lock? What is the voltage? I haven't seen anything like it, but I could come up with an LED substitute that would require a little Rube Goldberg engineering.

SA1911a1 wrote:Mike, doesn't that bulb come out of the holder? Either threaded or twist-lock? What is the voltage? I haven't seen anything like it, but I could come up with an LED substitute that would require a little Rube Goldberg engineering.

Steve, I tried to remove the bulb from the holder and it wouldn't budge (Maybe I am doing it wrong). I did finally find a GE 323 listed under aircraft bulbs for $10.95 (See link below), looks just like mine. I'm going to find a nut and see if I can fix the threads on the 323 bulb here and see if it fits in the sextant properly before I spend that much for a dinky bulb. Still coming up blank on the GE/MAZDA/EDISON 322 bulb though.

http://www.univair.com/electrical-light ... ight-bulb/

You need a small thread chaser for those stripped threads, a machine shop should have one to loan you for a few seconds.

I'll be damned if it doesn't look that that is a single piece. Can you power up the bulb outside of the assembly to make sure it works? You might have to get off your pocketbook and order the replacement.

steelbuttplate wrote:You need a small thread chaser for those stripped threads, a machine shop should have one to loan you for a few seconds.

SBP is not wrong on this one. You need a triangle file and/or a small round file to clean up the threads until it screws all the way in.This is if you think the bulb is good. This set would get you going on this project and many others.

millman wrote:

steelbuttplate wrote:You need a small thread chaser for those stripped threads, a machine shop should have one to loan you for a few seconds.

SBP is not wrong on this one. You need a triangle file and/or a small round file to clean up the threads until it screws all the way in.This is if you think the bulb is good. This set would get you going on this project and many others.

I've got a full set of jeweler files around here somewhere, either in the shed, garage, or upstairs in the gunroom, just got to find them.

What I don't understand is how the bulb works. The glass part of the bulb goes in the bulb hole, the black threaded portion screws into the hole like a plug of sorts. So how does power get to the bulb? Or is the threaded portion like the base of a normal bulb, just back ass backwards?

This bulb is used to illuminate the Bubble Chamber, the other two bulbs that work and are different then this one, are on the other side and illuminate the counter and the vernier disc/counter disc as seen in the photo.

The bulb itself looks like this.
The outer section is part of the equipment you took it from. It may be replaceable from the manufacturer. The bulb itself is replaceable. Sometimes they are stuck in the socket and very hard to get out. I hate this kind of bulb.

How many Mosin collectors does it take to change a lightbulb

steelbuttplate wrote:How many Mosin collectors does it take to change a lightbulb

Good one, guess we got a new running forum joke.......

SA1911a1 wrote:I'll be damned if it doesn't look that that is a single piece. Can you power up the bulb outside of the assembly to make sure it works? You might have to get off your pocketbook and order the replacement.

Just found 9 ea in original package (10 pack missing one) for $8.95 on ebay versus $10.95 for one bulb, so I'll have spares for less than the other site was selling one. Also found a sextant site, asked a few questions, and a gent there offer to overhaul my bubble chamber for free.

Now I just have to find a spare chamber to complete the display, woo hoo!

steelbuttplate wrote:How many Mosin collectors does it take to change a lightbulb

Got new ones on the way, need some Mosin collectors to help me install it.

42izzy9130 wrote:What's aircraft is the sextant from? I used to work/shoot sextant's for the Nav when I was a Boom on 135's, they call those "peanut bulbs" just as a future FYI. More pics of the sextant please! Good Luck

WWII era USAAF sextant, so a WWII or early post war heavy (Bomber or Trash Hauler, your pick). In my mind it's off a B-17, my favorite WWII bomber. It's a Bosch & Lomb A-8A Bubble Sextant. I'll get some additional updated pictures of it for you.

Boomer cool, flown as baggage on a Tanker a few times. Watched our F-15's take on gas pretty cool to watch. Then when I was in MC-130's watched as we took gas from tankers several times, talk about scary.

Years ago, in the 90's, someone fat fingered my AFSC from 122X0 Aircrew Life Suppprt to 112X0 Infight Refueling Operator on a printout they generate showing your skills, civilian equivalent etc. I still have that printout and it's still part of my official records, dumbasses. Then again while an ART (Air Reserve Technician) I was listed as African American for over 4 years in the OPM database. Talk about having an Identity Crisis........

42izzy9130 wrote:

ffuries wrote: Years ago, in the 90's, someone fat fingered my AFSC from 122X0 Aircrew Life Suppprt to 112X0 Infight Refueling Operator on a printout they generate showing your skills, civilian equivalent etc. I still have that printout and it's still part of my official records, dumbasses. Then again while an ART (Air Reserve Technician) I was listed as African American for over 4 years in the OPM database. Talk about having an Identity Crisis........

So not only were you dual qualified, you were also dual race, how cool is that?

Yeap I was multi talented according to my paperwork!