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  • Omnichrome HeCd laser

    From Daniel Tamisier@21:1/5 to All on Sun Nov 22 00:51:39 2020
    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

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  • From Andy Burns@21:1/5 to Daniel Tamisier on Sun Nov 22 09:46:27 2020
    Daniel Tamisier wrote:

    I found an old Omnichrome HeCd laser

    Presume you start at Sam's laser FAQ?

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

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  • From Phil Hobbs@21:1/5 to Daniel Tamisier on Wed Nov 25 08:06:14 2020
    On 11/22/20 3:51 AM, Daniel Tamisier wrote:
    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


    +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

    --
    Dr Philip C D Hobbs
    Principal Consultant
    ElectroOptical Innovations LLC / Hobbs ElectroOptics
    Optics, Electro-optics, Photonics, Analog Electronics
    Briarcliff Manor NY 10510

    http://electrooptical.net
    http://hobbs-eo.com

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