Omnichrome HeCd laser

[Daniel Tamisier]

Hello,

I am a beginner with laser. I found an old Omnichrome HeCd laser Series 39X, model 439XL Class 3b date sept 87. The power supply is model 100. For me it doesn't lase. I have only a very pale violet light at the output of the tube...
The tube lights but after 5 minutes; the light around the tube is blue. Owing to what I read in the manual (not complete...) it is not normal. The voltages measured on the banana plug at the rear of the tube are good. The counter on the small pcb in the tube box shows more than 3000 hours (not very good).
My questions:
Does this laser output a visible light or only an uv light ? there is no label about the lambda on the tube.
In the bore, the light is very intensive but stop before the end of the tube, is it normal? (obstruction by precipitation of cadmium ???)
I know general electronics but I am a novice with laser!
Thanks for your help.

Daniel from Paris France

[Andy Burns]

I found an old Omnichrome HeCd laser

Presume you start at Sam's laser FAQ?

<https://www.repairfaq.org/sam/laserhec.htm#hecnoohc>

[Phil Hobbs]

Post by Daniel Tamisier
Hello,
I am a beginner with laser. I found an old Omnichrome HeCd laser Series 39X, model 439XL Class 3b date sept 87. The power supply is model 100. For me it doesn't lase. I have only a very pale violet light at the output of the tube...
The tube lights but after 5 minutes; the light around the tube is blue. Owing to what I read in the manual (not complete...) it is not normal. The voltages measured on the banana plug at the rear of the tube are good. The counter on the small pcb in the tube box shows more than 3000 hours (not very good).
Does this laser output a visible light or only an uv light ? there is no label about the lambda on the tube.
In the bore, the light is very intensive but stop before the end of the tube, is it normal? (obstruction by precipitation of cadmium ???)
I know general electronics but I am a novice with laser!
Thanks for your help.
Daniel from Paris France

+1 for Sam's FAQ.

I don't know that model, but I've used quite a few lasers from that era.

HeCd laser tubes are notorious for crudding up the Brewster windows. If
the windows are visibly contaminated, the tube is probably toast.

Otherwise it might just need walking in.

Cheers

Phil Hobbs