ZA-21 Light

[Stevie342000]

That looks well made but would not expect any less from Neumann.

Still a couple of questions over this and then we should be done.

I assume it fits somewhere on the lathe or does it sit elsewhere?

Does it contain the prism(s) and some kind of scale in the eyepiece (I am assuming it has an eyepiece, not looked that closely at the pictures)?

Does it give you a reading directly in cm/s or do you have to do some maths or refer to a chart? Are there instructions on how to use it?

Neumann would have given this some thought and made the process as quick as possible, the BBC mentions it takes about 30 minutes? I am thinking they refined it so you got a direct reading through the eyepiece or does the scope/camera come into play here?

Well that was more than a couple of questions, maths was never my strongest subject

Agreed a picture says a lot more than many many words can but a video does show how it is used but alongside a verbal and written explanation (kept as simple as possible - English is not everyone's first language- we can all use Google Translate) goes a long way to fill in any gaps and then you get an moment.

The Buchmann-Meyer light technique is very niche, I can see why you need it and how you have thought about how you can use it along with other tools to develop further ideas and for critical alignment and product tolerance.

[ejemmons]

I find I can't wade through all the blegthorpe in this thread, so here's MY dos centavos: It's an incandescent lamp. ANY PSU will do, AC or DC. The pattern in the glass is like a gobo: no defined pattern edges; a frosted lamp would probably do as well. It's that 45 degree angle that matters... If you can sorta match the color temp to a pilot lamp, like a #47, never getting more white than the above yellowish glow, you'll be ok. If you run it 10% below that voltage, it'll last ALMOST forever....

[opcode66]

6v 15 watts
Any psu would certainly not work and most would blow the bulb.

I doesnt attach to the lathe. It is meant to be hung from your ceiling.

I will use a laser level for alignment.

[flozki]

i am shocked to see someone touching this
very valuable and rare piece of german
highend technology without antistatic gloves!

happy measurement!

[opcode66]

Hi Flo. Nice of you to drop by.

Valuable? No.

Rare? Yes.

High tech? No. And, that's the beuaty of it. Like records are high tech? High tech in 1930...

Gloves are optional. But highly recommended.

Possibly you'd be more interested in the 3d magnetic field mapping device??? In the works.

[ejemmons]

Oh dear, I had a "bench supply, variable" in mind. I'm just so used to this sort of tech it'd never occur to me to not ramp up from zero....

[opcode66]

Yes, but to where??? Having never seen one on and having no markings it was a question how bright is the desired brightness. It will start to shine below the rated voltage and will continue to shine above... Until you burn it out. Poof. I have never said it wasnt possible to do this. But, the exact issue is where do you stop? Instead of guessing I wanted to know the spec. And, I eventually found it. Anyone should be able to treat their gear as carefully as possible or not. I choose the former over the later. If I were to have guessed, I would have said 9v or 12v or 26v which are some of the standard voltages in the lathe itself. So, would 9v or 12v have fried the filament? If one assumed the voltage was much higher than the actual rated voltage of (a small value of 6v), then
one might have destroyed an extremely hard to find bulb. I am more cautious.

[Radardoug]

Have you tried putting a regular 6 volt 15 watt MBC lamp in there? If you need diffusion you could put a peice of a suitable diffusor in in front of the lamp.
It is not clear whether the lamp has special optical properties, or whether it was just what they bought at the time.

[opcode66]

The glass has a pattern to it. Just trying to get to a bassline. Then do the same in a more modern fashion. I want to be able to make accurate measurements. Lets just leave it at that for now.