Changing diffuser on Dichroic head mixing chamber

Discussion in 'Enlarging' started by jstewart, Jan 21, 2005.

  1. jstewart

    jstewart Member

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    Does anyone know how to change the white diffuser on a Chromega dichroic head mixing chamber?

    I recently bought the head used and it appears the white plexiglas diffuser may have 'hot' spots on it. I'd like to replace it, but it's not obvious how I do this without taking the whole chamber apart.

    Any help is appreciated.

    Jim
     
  2. Bob Carnie

    Bob Carnie Subscriber

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    I think you have to take the whole chamber apart. You may find that the foam inside needs replacement as well, also the infared glass needs to be clean and clear of cracks as well.
    KHB in Missisauga Ontario will be able to help you out with any tech questions or part issues.
     
  3. Robert Brummitt

    Robert Brummitt Member

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    Yes you have to pull the box apart. Are you getting soft white spots? That might be dust in the chamber. Use a air gun for that.
     
  4. brimc76

    brimc76 Member

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    I replaced the foam in both chambers that came with my Dichroic head, it was very easy. The white piece of plexiglass it NOT included in these kits though - you would have to order that specifically. I got both kits from KHB in Mississauga.
     
  5. dancqu

    dancqu Member

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    Maybe no help but I shelved a Meopta 6 x 6 dichro due to
    an overly thick, in center, bottom diffuser. Prints were very
    much less dense in center than around the edges. Dan
     
  6. Ronald Moravec

    Ronald Moravec Member

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    You can get what is called a liner kit that has new foam. I think the diffuser is included, but ask when ordering. A small screwdriver is all you need. i the foam is discolored, take it out and spray paint it white and reinstall. Save a LOT of money as the liner kit is expensive. You could also cut your own foam using the old as a pattern. Use a razor knife from a hobby shop. Or a hot wire cutting tool made for this. Another model tool. I do railroads and airplanes too. Hobbyed out.
     
  7. JackRosa

    JackRosa Member

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    Depending upon what enlarger model you have, the diffusing glass may be below the mixing chamber, in its own 'carrier'. You pull this frame/carrier out and voila' there's your diffuser.

    If you have access to an enlarger with uniform/even ilumination, make a Zone Vcontact print through the diffuser to determione whether the diffuser is providing even/uniform light.

    Hope this helps.
     
  8. glbeas

    glbeas Member

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    Some diffusion chambers have secondary correction plates inside that are to kill the center hot spot. My old Minolta Mod III that I passed on to my brother has this. Its on top of the foam chamber, just a thin metal screen cut in a circle that was glued to the upper diffuser. By the time I gave it away the circle had come unglued and was rattling around on the inside of it. Took very little effort to disassemble and repair.