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Thread: another resistor question

  1. #1
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    Post another resistor question

    OK here is what I did. I got a 82 ohm resistor and cut my rca cable. I stripped away the sheilding so the wire was exposed. I then sodered the resistor to connect both sides of the rca cable again. My video card did not pick up the lcd. So i moved it to my dvd player and it worked but very very bad. Like no color and wavy, but you could make out a picture. I take it I messed up somewhere. Did i do it right? or is there a much easier way to do it. PLease explain this in idiot terms so i can understand.

  2. #2
    Newbie masterful's Avatar
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    Ok, here's the deal (this information was given to me here as well):

    Strip the cable back (no reason to cut it in half), and you will see the shield wire on the outside, and another wire on the inside (center pin wire). Strip the center wire as well. At this point you should have both the shield wire and the center pin wire visible. Solder your resistor so that one end of the resistor is connected to the shield wire, and the other end is connected to the center pin wire. Wrap it good with electrical tape so the shield wire and center pin wire don't short against each other, and try it again. That should work just fine. Exactly what I did and it works like a dream.

    ____________________
    -------------------- <----Shield Wire
    / <---Resistor
    -------------------- <----Center Pin
    ____________________

    Jeffrey.
    "Quitters never win, and winners never quit, but people who never win, and never quit are idiots."

  3. #3
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    that makes a lot more since to me. I was having the same problem. I cut the cable in half and soddered the resistor to both ends of the center cable. The shielding wire is the fine peices of copper wire in between the shield for the center wire?

  4. #4
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    I agree with masterful. You have to connect the resistor across the center wire and ground, that sets the impedance at @ 75 ohms.
    If it ain't broken, open it to see what makes it "tick".

  5. #5
    Raw Wave Rob Withey's Avatar
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    Yep, standard transmission line theory. Better signal quality, designed to reduce signal reflections at the far end.

    Rob
    Old Systems retired due to new car
    New system at design/prototype stage on BeagleBoard.

  6. #6
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    I have a problem after doing this:

    I went to Ratshack and got an 82 ohm resister - put it inline - and the screen got alot darker...the vid card picked up the LCD well, but the screen is alot darker...

    Could it be that 82 ohms is too much???

    Help!

    Thanks!

    -Mike
    "As God as my witness...I thought turkey's could fly"

  7. #7
    Raw Wave Rob Withey's Avatar
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    You shouldn't put it inline, you should put it between the signal and ground at the end which the screen is at.


    Rob
    Old Systems retired due to new car
    New system at design/prototype stage on BeagleBoard.

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