I'll have to dig out my Jr. I'm gonna say some 2 part epoxy should hold the ballast can together .

So here's a Pic of it when I first got it home

https://www.lighting-gallery.net/gallery/displayimage.php?album=8301&pos=11&pid=242409

As you can see the Knuckle itself luckily isn't snapped, but the circular base of said Knuckle mount has come off the cylindrical ballast can. Looking closely you can see some kind of orange adhesive that gave way. It might be possible to reattach the Knuckle mount to the ballast, but I'm not sure if this is still the best way of going about this.

I should have linked photos earlier but here ya go

  I'll see if I can find them again . They were listed in web finds at one point . IIRC they were a good bit over priced .

 EDIT : I can't seem to find them . I'm assuming the listing expired . If I see them again I'll let you know .

I might get a couple for myself to run off my step up transformer.

Can you send me the link to those 208V self ballasted mercury vapor lamps you found in a PM?

 There's a pair of 208v Self-Ballasted Mercury lamps on eBay right now .

 Look thru this GE catalog on LampTech. https://www.scribd.com/document/113710933/GE-1975-Lamp-Catalog  There's lamps from 6w to 1,500w using all sorts of 120+ voltages from 135v to 300v using bases from Candelabra to Mogul !

 My favorite is the 10w , 250v D.C Bayonet indicator lamp ! 

 There is a 25w & 50w medium based A-19 listed as 300v. The 1st 277v listing is for a 100w A-21

Replaced an old, worn-out Universal Watt-Reducer 446 ballast that I had inside one of my garage lights, which was becoming hard to start. I replaced it with the Advance REL-2S40-SC electronic ballast because I was able to get one cheaply on eBay, and I have had good luck with that model so far in one of my other fixtures. It actually has a true rapid-start startup, which is uncommon for electronic ballasts.

Setting safety aside (assuming it's the 1940s), would it be more efficient?

When quartz pinch seals are made, the seal is typically made with molybdenum foils going through the quartz. I have the following questions about this process:

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1) Why Molybdenum?
Quartz has a CTE of around .55e-6 which is very very low. So you would want to use the metal with the lowest CTE that you can find, right? Well (according to Google AI overview) molybdenum has a CTE of 5.2e-6 while tungsten has a CTE of 4.8e-6. Why wouldn't they choose tungsten for this application?

2) Definition of "Foil"...
So they use molybdenum foil for these seals, but what exactly do they mean by foil? Are we talking about .1mm or something like .01mm? I would assume the thinner the better, but obviously there is a practical limit to the thinness of foil.

3) "Feathered Edges"?
I always hear descriptions of Mo foil seals mentioning that the edges of the foil are "feathered". What is that supposed to mean? When I look at a halogen capsule all I see is foil, I don't see any visible edge treatment done to the foil.

4) Vycor Glass?
I just learned that there is something called Vycor, which is 96% quartz, but technically a type of borosilicate glass. It has a CTE of ~.75e-6. Was this ever used in lamps? I feel like straight up quartz might be overkill for something like a small halogen capsule.

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Thanks!

I have read that some GE linear halogen floodlight fixtures would take 208V linear halogen lamps.

Now that I have a step up transformer that converts 120V 60Hz to 208V 60Hz, I am now able to comfortably run 208V 60Hz only HID ballasts. If anybody has been wanting to get rid of 208V 60Hz only HID ballasts, I am more than happy to take those ballasts off your hands!!!