Urania neon tube specs

#1: Post by **mingiunate** » May 1st, 2022, 10:30 pm

Hi all - I'm starting a rebuild project for a 2nd gen Urania from 1957, 1 group. I'm in the process of documenting the rebuild which I expect to post in a thread soon, but for now, wanted to reach out about the back neon. I think I was lucky enough to have a very complete machine (albeit quite dirty) with all original parts present -- including the neon tube in what appears to be a non-burned out state (once i could inspect it after gently washing it off with some soap and water)!

The transformer was not included, unfortunately, but I was hoping to test it out to see how it looks. Based on my calculations, the tube only needs ~1k volts to ignite, but I'm unsure of the current needed. Does anyone know which transformer might work to test this out? I'd prefer not to spend a small fortune on a test. I see this one on amazon:
https://www.amazon.com/dp/B07GPV5KSM?ps ... ct_details

But it makes me a bit nervous not even being UL certified.

Please let me know if anyone has any thoughts, thanks.

#2: Post by **mikel** » May 1st, 2022, 11:18 pm

This thread might be of help?

Urania neon tube specs, anyone have them?

#3: Post by **Marcelnl** » May 2nd, 2022, 5:22 am

I never got around to investigate having a batch made, the signing comp I wanted to work with had been sold...
I just sent an inquiry to a bespoke Neon maker, however I dread the price.

#4: Post by **Paul_Pratt** » May 2nd, 2022, 7:09 am

Yes 1kv should be ok, it's just a very small lamp.

May 2nd, 2022, 7:54 am

Thanks! - Do you know what would happen if I used the 3kv transformer linked below when the lamp only requires ~1kv? I can't seem to find a reasonably priced 1kv transformer. Is 30ma the right current?
https://www.amazon.com/dp/B07GPV5KSM?ps ... ct_details

#6: Post by **Marcelnl** » May 2nd, 2022, 9:46 am

I have no clue what current is required but I expect it to be far less than 30mA which is no issue...I THINK it should work as you need a certain voltage to 'ignite' the tube and that voltage increases with the length of the tube.

#7: Post by **ira** » May 2nd, 2022, 12:47 pm

The important thing is current, one the tube lights the voltage rating is not relevant. The current controls the brightness and running temperature and likely tube life, the voltage is needed to get it started. If 30ma is to much, then that is the wrong transformer.

#8: Post by **Marcelnl** » May 2nd, 2022, 2:10 pm

would the tube not simply draw the current it needs?

#9: Post by **ira** » May 2nd, 2022, 2:42 pm

no, it will take all the current the transformer provides.

May 2nd, 2022, 3:07 pm

are you sure? I'm finding some theory but so far from what I see the voltage is what drives these tubes and the current is not mentioned anywhere when discussing power supplies.