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Barco 808s - Tube brightness

Discussion in 'Projectors, Screens & Video Processors' started by mikett, Jun 17, 2005.

  1. mikett

    mikett
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    Its getting late but I have to get this off my chest as well.
    The blue and green tubes are new but the red is old, very old . No screen burn but then the mileage is 22K.
    During convergence the red is very faint when compared to the green. But then the blue is dominated by the green.
    Impossible to answer I guess, but should I be looking for abetter red tube or should I wait for things to settle down a bit. It does occur to me that G2 adjustments may be appropriate. Do you require the half dozen whiskies approach for that one.
    Mike
     
  2. Roland @ B4

    Roland @ B4
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    Who changed these tube out?
    Does sould like G2 which sould need doing about once every 2 years or when a tube is changed.
    Whisky ansd high voltage not a good idea.
     
  3. cosaw

    cosaw
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    mikett - I recently balanced my G2s on my barco 500 which is my first crt pj. Don't fully understand how g2s affect colour temp on my machine. I'm feeding it via pc and the 500 just seems to have one colour temp so I adjusted it for that.

    That aside - I found red was under-driven and green was a little too high. Consequently all my greyscale was tinted towards green. I checked and recalibrated g2s with the aid of a greyscale pattern in the Nokia Monitor Test Prog - can't remeber the link but will look it up for you if you need it.

    Anyhow as a result of g2s now being properly adjusted I find that at the moment I get the rasters to glow for raster centering (contrast 10 then turn up brightness till they just light - as advised by many) - they all come up and light at the same time and rate - they didn't do this before - so this could be another good way of seeing whether g2s are balanced or not.
     
  4. mikett

    mikett
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    I hate whisky after an experience one January 1 many, oh so many years ago. So thats OK. It has to be said that by this stage even though I have not touched the G2 adjustments, the red tube is fighting back. It is obviously still a good idea to check G2 but as things are obviously changing quite rapidly should I back off for a little while. Or maybe do it now and then check later.
    Mike
     
  5. Roland @ B4

    Roland @ B4
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    The G2 ajustment should have been set whent he tube was changed. If you trust who did this then leave the adjustment. There may be something else causing your colour differnce.
     
  6. mikett

    mikett
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    This evening I have made an attempt to make the G2 adjustments. I have had no problem with the blue and green which did need clockwise adjustment of the pots to cut out the green neons. Proof indeed that there had only been a physical installation of the tubes.
    The red tube I cannot set with to the green neon out. At the extreme end of the clockwise range the brightness increases substantially and to my weary eyes looks as strong as the blue and green. However I felt that it was better to switch off rather than set it at the maximum of the potentionmeter in case I was causing overloads elsewhere. This tube has done 22K miles so does all this mean the tube is at the end of its life. Will I cause damage running the pj in this state.
    Mike
     

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