Oltronix A2,5K-10HR 2,5kV/15mA PSU - Looking for schematics


New Member

Let me introduce myself; I'm a Dutch guy who has stumbled upon an old Oltronix A2,5K-10HR PSU. Apart from my trusty Hameg oscilloscope, I didn't own any tube operated lab equipment before (and the only tube in the Hameg is the CRT, so it doesn't really count right?). I thought it would be a nice hands-on introduction into this older type of equipment, and also provide me with some means to experiment with tubes in the future (Photomultiplier tubes, geiger tubes, etc). Before gently powering it up, I visually inspected the caps, and replaced one cracked RIFA smokebomb. Filament voltage is fine, the 8068 tubes seem to be ok (shiny getter, I don't know where to look for otherwise, hints are welcome), but the voltage regulation at the output is 150V off, and the current limit behaves a bit jumpy.

I'm looking for schematics and a user-manual or specification sheet, so I can further restore this piece of equipment (or just find out that it's within specification :-D).
I found out that Oltronix had a Swedish history, with an early link to the Netherlands. My A2,5K-10HR was assembled in Leek, the Netherlands. Sadly they've gone out of business in 2020. While searching I found that a lot of Oltronix equipment is discussed in this forum, and schematics have been shared in this thread before, so I was hoping that someone here could help me out. Would be nice right? A Swede helping a Dutchman in restoring a piece of common history :)

P.S. I don't want to offend anyone by writing in english on this Swedish forum, but I think google translate generally does a far worse job translating english to swedish than most Swedes do, especially in this area of expertise.


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New Member

I hope you don't mind if I borrow this trace.

I have Oltronix B402 (Labpac?) which is otherwise functional but 20V output current meter is not functional.
I would like to refurbish this but I don't have a schematics available. Simple Google search wasn't successful.

Just wondering if somebody in Sweden could help?

Best Regards,


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I went looking in my library but did not find anything related to the B-402. I found a schematic drawing for the B-401 (single output model) which seems quite similar. I can scan and mail you the schematic drawing if you provide me with an e-mail address.

I guess Oltronix would use the same circuit solution. The schematic is detailed enough to be used for trouble shooting.


New Member

I suppose this will be close enough. At least the PCB for each output looks identical.
It's great to see that somebody is keeping paper library.

My email

Please replace () with proper character.

Best Regards,