You should consider this a lucky find, I was restoring a Soviet tube scope, somewhat local clone of Tek 310, out of nostalgic reasons. Brought most of the circuitry to working order by replacing all of the paper capacitors and some other minor parts around, CLAing the switches, but was stuck with half-dead power transformer having deteriorating paper insulation. Original transformer has circa 12 windings (!) about four heater windings, ~three anode ones and two high voltage.  So far the oscilloscope works on "the external life support" feeding substitute voltages from some extra transformers outside but that is far from complete restoration.

I bought a new 6500K 70W MH lamp for my tracklight several weeks ago, and its DyI emission is very weak, even today. And no, it have a good amount of halides inside and large enough heat reflective coatings at the arctube ends, and operates on an electronic HID ballast.
Why the DyI in my lamp is so weak?

My hostel have a new standing cordless vacuum cleaner, which don't have the usual blower noise of most vacuum cleaners, but more like that of a piston pump that used in pressure washers.
Why?

Thanks! I actually already found a working used transformer on Ebay that was almost exactly what I needed. Except one of the windings that needed to be 5V was 6.3, but it was just for a rectifier so it was easy to replace the type 80 that it asked for in the schematic with a 6AU4 I had.

The transformer also has another winding of probably over 1kV, and I fried my cheap meter trying to measure it  . It isn't used here since the 902 CRT operates at a maximum of only 600V. This transformer was almost certainly used in a scope in the past.

Best one I had was in my living room light. It takes 5 E14 lamps, originally halogen, but made the switch to LED 6 years ago. The second inning of LED lamps came in Oct 2021. One of them, two months later, went out like a roman candle. It was flickering and buzzing for a minute, before going out and erupting smoke for a solid 5 seconds with a very loud hissing to go along with it!

Good luck building this. The circuit is of course not overly complicated, and may be some fun. IMO, the major obstacle is to find some suitable transformer with necessary output voltages. I'd try to use some modern off-the-shelf DC/DC HV converter modules, though impulse noise requires some care, as it can spoil the circuit!

My most memorable one happened in December 2020, it was a typical working week morning, I was in the shower, it was about 6:30am.
I heard a scream from the kitchen, (not an absolute fear scream), but that scream women do when something makes them jump! 🤣
Getting down stairs I met the missus in the kitchen with a dazed and confused look on her face!
She said there was a loud, electrical pop, a bright flash of blue from the top of the kitchen units, and some form of projectile shoot across the kitchen ceiling!

She then looked back to the point of the flash to see a small plume of smoke rising up above the top of the units! 🤨
The culprit?, I have 12, GU10, LED lamps at the top of the kitchen units, mounted on their side that throws light across the ceiling creating a neat up lighting effect, and it was one of these ‘mini cannons’ that was the cause!
After taking the thing apart, I found one of the capacitors exploded, with all that stringy hairy stuff protruding from the bottom like the rocket flames from Saturn 5! 🤣🤣🤣
This explosion was enough to forcefully eject the plastic cover from the lamp, and send it across the kitchen at questionable speed! 🤪

I’ve never had such an EOL on any other lamp in the house!

🤣🤣🤣🤣excellent, that’s a proper EOL test!

Found these in a video of 1940s Berkeley and found these on the Eastshore highway. Who made these and what light source did they use? I couldn’t possibly imagine that these were incandescent.

I'm back to revive this thread again... there is a possibility that I may be purchasing LED light tables, for use in my upstairs loft.
I of course plan on taking those LED strip lights out and replacing them with fluorescent T12's. Right now, two F15T12 strip fixtures that
can fit HPF Trigger Start ballasts, look to be the best bet... or F14T12 fixtures, same. I'd be using two of my HPF Trigger Start ballasts,
one in each fixture. This idea would be the final lighting addition to my recently completed lighting project in my living room, for the
upstairs loft only though -- no light tables will be used downstairs.
Although undercabinet fixtures might actually work in this case as well, I'm primarily focused on trying to find two F14T12 or F15T12 strip
fixtures that can fit the HPF single lamp Trigger Start ballasts.