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Thread: Recomended cable?

  1. #1

    Default Recomended cable?

    I've read a lot of information about laser and lasershows. But there is one thing I just havn't found anything about. And that is, what cable should be used from the DAC to the scanhead.

    Cat 5 FTP cabel? Or individual shelded balanced microfon cable?

    I have no idea what would be recommended.
    You know, I have one simple request. And that is to have sharks with frickin' laser beams attached to their heads!

  2. #2
    Join Date
    Feb 2005
    Location
    Florida
    Posts
    802

    Default

    Hi Groover... Welcome

    You can use either...
    I guess it depends on your application ...

    Some DACs output unbalanced ..(not sure why tho)
    As I would think we would want both sides of the waveform (more resolution).
    ... so regular audio cable (single conductor shielded) works for that.
    I dont recommend this tho.
    As balanced cable is so much more forgiving

    If you are just using it at home , say less than 10m regular
    Cat5 is fine ..

    Shielded balanced audio cable is better IMHO...
    I have heard others have had good luck with extended lengths..

    I have also heard of people using Cat 5 cable but that is a little more
    detailed..
    You must have the style that shields the individual pairs
    or
    Do some fancy grounding of certain pairs..
    Plus you may need several runs of this for full control depending on what you are doing.
    Therefor.. you will need a break-out box at each end depending on the connectors used.
    Use different colored tape on ends... but this is a mess to deal with.

    I myself in the past ,.have had no luck with this as the cat 5 I tried was only
    outer shielded ...
    I had too much crosstalk in that cable
    no matter how I wired it..

    I prefer as many do...
    shielded audio cable for the scanners and 25conductor cable (wired ILDA style) using db 25 connectors for the other signals.!!!

    The idea is to keep the audio signals INSIDE the cable.
    And control signals universal... for easy trouble-shooting in the dark
    And interference like power controlled lights and other signals OUTSIDE the cable.
    All this without loss... and fuss
    Low performance systems it may not matter
    Maybe some others will chime-in with what works for them.
    "My signature has been taken, so Insert another here"
    http://repairfaq.ece.drexel.edu/sam/laserfaq.htm
    *^_^* aka PhiloUHF

  3. #3

    Default

    heres my trick:

    shielded USB 2.0 cables. cut off the head and solder your new connectors on.

    Seriously. They are spot on perfect for galvos. They even have 22 awg power leads as specified by cambridge. The colors cambridge lists in their hookup sheets even match.

    Hell of a lot cheaper than cambridge also

  4. #4
    Join Date
    Jun 2005
    Location
    SoCal
    Posts
    490

    Default

    Your cable choice will be determined whether your projector
    is differential or single-ended... If it's single ended, you will
    definitely want to shell out bucks for very well shielded cables,
    if you have differential, then the cables don't matter so much.

    I use CAT5 for short runs on single color lasers... There's not
    enough wires in CAT5 for more than one or two colors and
    differential signalling...

    I also use professional shielded 15-wire cabling for long runs
    and real projector systems... With ILDA spec you don't get
    something for nothing, and your configuration may need all 25 pins.

    The best/cheapest way to get the 15-wire shielded cable is to buy
    new old stock of "Thicknet" which usually come with MAU/AUI DB15
    end connectors... Replace them with DB25 and you're set. These are
    good to Cambridges max distance of 300', but I would strongly
    recommend against runs over 50' unless you turn professional
    (i.e. get more experience with how to route the cables to minimize RF noise)

    You can also buy premade professional shielded DB-25 cables,
    but I think the shielded stuff is too thick to be convenient and you
    almost never use all of the pins as they are not always necessary.

    The simplest way (if you're using differential signalling) if you're
    only talking say 10-15' of wire is to just run to Fry's or CompUSA and
    buy printer cable extenders/printer switch box cables in the length you
    need and the appropriate male/female DB25 connectors your system is
    configured with.

  5. #5
    Join Date
    Jun 2005
    Location
    SoCal
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    Default

    Oh and details... In CAT5 the colors are coded to be useful
    for differential signalling...

    so I would run X+/- over Orange and Orange-White,
    then I would use Y+/- over Green and Green-White.

    Your I/B+/- would run over Blue and Blue-White.
    And you have 2 wires left over which you can use for shutter or
    whatever.

  6. #6

    Default

    Quote Originally Posted by yaddatrance
    Oh and details... In CAT5 the colors are coded to be useful
    for differential signalling...

    so I would run Y+/- over Orange and Orange-White,
    then I would use X+/- over Green and Green-White.

    Your I/B+/- would run over Blue and Blue-White.
    And you have 2 wires left over which you can use for shutter or
    whatever.
    This is a funny coincidence Iím currently running about 4í of Cat 5 cable. Y+/- on the orange/orangewhite and X+/- on the Green/greenwhite. Blanking on the blue/bluewhite. X and Y is differential signal but not the blanking, TTL 0 and +5V there.
    You know, I have one simple request. And that is to have sharks with frickin' laser beams attached to their heads!

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