Video Interference?

Discussion in 'Archived Threads 2001-2004' started by Christian Speights, Mar 28, 2002.

  1. Christian Speights

    Christian Speights Stunt Coordinator

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    What are some possible causes of this and what are some potential solutions?
    I was getting some faint patterns/moving lines on my screen watching satellite and DVDs but was running all of the signals through my Denon 3200. When I ran the DVD direct via S-vid to the back of the set, presto! No more patterns.
    Could this be due to interference caused my the nest of cables I have back there? Is it possible that the Denon is no longer up to the challenge? I am using decent cables (Monster Video 3) so I don't think they are the cause. Anything's possible though.
    You folks have any quick fixes that can help me clean this up? I would love to run everything through the receiver so I don't have to change inputs on the set and I'm just not ready to upgrade yet.
    Of course, that's practically a mantra around here...and I have had my eye on the AVM20.
    Pease save me from myself. [​IMG]
    Christian
     
  2. Bob McElfresh

    Bob McElfresh Producer

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    Well, the reciver being the central point for all signals (including unshielded speaker cables) it is a high concentration of noise.
    But all your interconnects should be made with coaxial cable that include a shield.
    So it's a mystery. [​IMG]
    The first thing to do is to disconnect/reconnect all interconnects. A loose plug is often the problem.
    If that does not solve it:
    I would set the system up with a DVD player playing a loop that shows the problem. Then do the following until the problem disappears:
    - Check the room for "dimmer" switches on lamps/fans. Turn these off.
    - Turn off all lights (hallogens) in the room
    - Unplug the CATV coax feed from all your equipment
    - Unplug the DSS sat coax from the equipment
    - Turn the volume all the way down, or mute the receiver. (Since the speaker wires only create fields when power is running down them, this should eliminate the speaker wires from the equation.)
    - Move all power cords away from the interconnects
    - Check the SVideo cable from the receiver to the TV and make sure it is not near power cords.
    If the problem still persists:
    - Pick each device other than the DVD player and disconect it's interconnects from the receiver. (Use labels so you can put them back later). After each cable is pulled, check the screen to see if the problem goes away. Then pull the power cord for that device so it is totally disconnected from anything.
    - When only the DVD player is left, try moving the power cords for the TV/DVD/Receiver to their own power strip.
    At the end, you should just have the SVideo feed from the DVD player, and the SVideo feed to the TV. If this is the only thing left, then one of the SVideo cables is bad, or somethings wrong with the receiver signal switching.
    Good luck and let us know what you discover.
     
  3. Christian Speights

    Christian Speights Stunt Coordinator

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    Thanks for the advice Bob. [​IMG] I will definitely give it a shot this weekend. I'll post again when I have results to share.
    Christian
     
  4. Christian Speights

    Christian Speights Stunt Coordinator

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    So I made a tirless effort to clear up the mess of cables behind my TV today in an effort to clear up some of the interference. I took Bob's advice into account and it seems to be all cleared up...literally.

    No weird patterns. No unsightly mess.

    Totally worth it.

    Christian
     
  5. John Royster

    John Royster Screenwriter

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    glad to hear. I've always been told (and follow religously) to keep audio/video interconnects AWAY from power cables. One side of the rack is for power, the other for interconnects. Now if we can only figure out if your problem was related to a loose cable or power EMF.
     
  6. Bob McElfresh

    Bob McElfresh Producer

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    Cool. Glad it worked out.
    I try to do a "HT Cleaning" every year. This includes:
    - Trimming both ends of my speaker wires to expose fresh copper.
    - Cutting and putting on new "F" connectors on my coax
    - Un-plugging every interconnect.
    - Dusting & using a soft tooth-brush to dig out the dust bunnies from the un-used connectors
    - Bundling/routing the cables
    But then I'm one of those sick individuals who thinks this is a fun thing to do on a rainy afternoon. [​IMG]
     

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