which MN bulbs are these?

While testing of my PhD-M6 pack, I came across these two non-labeled MN bulbs in my "collection", but I honestly don't remember what they are - seems that before SF came with the black body and white lettering, they were using these color-coded bodies.

Does anyone know with fairly good certainty what these are?
(by the way, illumination for the pictures comes from a Mule with a Nichia 083 warm white LED)





Close-up:



Could these be like really old MN20 and MN21 bulbs?

Will

The black anodized lamp is an N62, used in the old SF 12PM/12ZM.

The N62 bulb envelope does not have the straight sidewalls like the MN lamp on the left. Also, the outer spring contact is shorter relative to the inner spring contact. It also looks like the springs are of a duller finish, consistent with the old "N" series lamps. The MN lamps have shiny springs.

Finally, the N62 doesn't have its lamp designation etched into the anodizing.

The N62 is a serious 123A battery drainer.

Justin Case said:

The black anodized lamp is an N62, used in the old SF 12PM/12ZM.

The N62 bulb envelope does not have the straight sidewalls like the MN lamp on the left. Also, the outer spring contact is shorter relative to the inner spring contact. It also looks like the springs are of a duller finish, consistent with the old "N" series lamps. The MN lamps have shiny springs.

Finally, the N62 doesn't have its lamp designation etched into the anodizing.

The N62 is a serious 123A battery drainer.

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Neither one of these has a designation in the body. They must be pretty old then.

Do you know the voltage/current and lumen rating for the N62 bulb?

Any idea about the other bulb?

The pink one looks like an MN10 perhaps?

The other bulb is an old MN bulb before SF went to the etched designations. It was a holdover using the color code. But I don't know which MN lamp it is.

The N62 pulls something like 3.7A from 4x123A. So figure ~2V per cell at best? Put it on a bench supply and feed it voltage until the current reads 3.7A.

This link says 7.65V.

The purple is the MN20 I thought.

OK, thanks guys. It certainly looks like the purple one is a "very" old MN20, and the "big" one is the N62. I will label them now so that I don't have to keep guessing in the future.

Will, I think those old bulbs were more prone to shatter than the new versions. I can't remember where I read that, but I'm fairly sure it was posted by someone reliable. I just mention it so you are forewarned - not a good thing to end up with a bulb that has gone off pop, and small shards of glass inside your KT4 head.

DM51 said:

Will, I think those old bulbs were more prone to shatter than the new versions. I can't remember where I read that, but I'm fairly sure it was posted by someone reliable. I just mention it so you are forewarned - not a good thing to end up with a bulb that has gone off pop, and small shards of glass inside your KT4 head.

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Thank you David. My "plan" was to try them with the PhD-M6, since the new hybrid soft-start is even gentler on bulbs than before - the hope was that the slower start will negate the chance of the bulb exploding, but if they are so "delicate", it might not be worth the risk then.

If the black one is in fact an N62, then it should run at the 7.4V setting pretty nicely.

Eric

I concur, the purple one is an old MN20 and the other is an N62 (I have one of those).

Is it safe to run the N62 in stock M6 or M4?

I agree, I think that is an MN20 if I recall correctly they were purple and the old MN11's were pink. MN10's were orange..ect.

M4 should have no issues -- functionally it is a 4x123A host just like the old 12ZM. In fact, the MN61 HOLA lamp for the M4 seems to be a higher wattage draw than the N62 is -- maybe 32W vs 28W. The glass window of the KT4 TH also should be that much more heat resistant than the Lexan window of the 12ZM's TH. I would assume that the KT4's shock foam insert can handle the N62's heat.

The M6 may have trouble driving the N62 at sufficient voltage. The N62 needs roughly 7.5V, or about 2.5V per 123A in the M6 (which uses two parallel banks of 3x123A in series). Thus, each bank of 3x123As has to deliver about 1.8A, and I don't think that a 123A can hold 2.5V per cell at that draw.

Personally, my opinion is that the N62 is a totally impractical bulb when using Li primaries. Great output, nice wow factor, but it just consumes 123As.

CPFer cenz has apparently run his N62s successfully with 2xAW18650 (you'd have to bore your M4, get a different battery tube, or risk running 2x17670). You could also get a PhD-M6 loaded with 3xAW17670 and run the N62 with a Vbulb setting of say 7.5V. The run time will be short, but sweet.

The N62 was only ever designed to be used for a minute or two by a SWAT entry team. In that use it is practical. It was never meant to be an MN02.

The extreme narrowness of your application as a counterexample to "demonstrate" N62 practicality IMO simply further highlights how impractical that bulb is for 4x123A direct drive.

All my MN61s are obviously lower output and substantially lower runtime compared to the N62s I have. The Lexan windowed TurboHeads are fine for the N62's short runtime.

The Millennium TurboHead is used by the M6 MN21 - no foam heat issues

Size15's said:

The Millennium TurboHead is used by the M6 MN21 - no foam heat issues

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No foam issue is when using primary 123's at spec.
Overdriving MN21 for long continuous run will produce excessive heat and some damage on foam and lexan lens.

wquiles said:

OK, thanks guys. It certainly looks like the purple one is a "very" old MN20, and the "big" one is the N62. I will label them now so that I don't have to keep guessing in the future.

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Hi, Will

I have both of those lamps, and you have identified them correctly. I don't know about that version of the N62 being fragile, but as others have said, the purple MN20 should be retired.
The N62 at 7.5V with the Ph-D M6 is quite amazing. Fantastic throw as well.

leukos said:

Hi, Will

I have both of those lamps, and you have identified them correctly. I don't know about that version of the N62 being fragile, but as others have said, the purple MN20 should be retired.
The N62 at 7.5V with the Ph-D M6 is quite amazing. Fantastic throw as well.

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I guess I will have to try the N62 with my own PhD-M6 pack - thanks

Will