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VGA over Cat 6

Discussion in 'Multimedia, Projection, and Show Control' started by FMEng, Apr 8, 2009.

  1. FMEng

    FMEng Well-Known Member Fight Leukemia

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    I need to run UXGA (high res VGA) over about 200 feet of Cat 6 cable, from a computer to a projector. I'm looking at extenders from Smart-AVI, Geffen, and Kramer. Can anyone give me comment on good or bad experience with any of these products?

    Thanks,
     
  2. ruinexplorer

    ruinexplorer Minion CB Mods Premium Member Fight Leukemia

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    Do you already have the cable? If so, I would check to see which models will accept Cat6. Some models will only pass signal on Cat5 or Cat5e. I haven't used Kramer, but Geffen and Smart-AVI are decent over that run. I prefer Magenta Research for high quality and reliable video transmission.

    Edit: I forgot to mention Covid as a very reliable device as well.

    Check out a few of the other threads in this forum as this topic comes up fairly often.
     
    Last edited: Apr 8, 2009
  3. NickJones

    NickJones Active Member

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    VGA does not travel well over about 20m. There VGA amps out there but it would be very very expensive. VGA is 15 pin (if memory serves correct) and Cat5 is 5 pin. Have you considers streaming the video over a network. You could use VNC to do this. You need use Cat6 or Fiber to get optimal speed if you are doing video. Alternatley you could consider scan converting it to RCA/composite then you can run it through Cat5. TVOne sells them. They make good TV quality gear. A quick Google should turn up there site. As it was Xga you might have to set it back to 800x600 to get the best scan conversion. Ours runs at 1040x480 but it does look a little letter box like. This is fine thoughnif you are projecting it but not as good on a TV.
    PM me if you need more help.
    Nick
     
  4. Hughesie

    Hughesie Well-Known Member

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    Im the type of person who tries to keep it simple, and your observation about 15 to 5pin is a rather far fetched and im pretty sure there will be a line forming behind me laughing at you right now. As for your budget solution, it addresses the problem but clearly the post is looking at a high end solution and not a system that will require constant work and head aches.

    also cat5 is 8.
     
    Last edited: Apr 8, 2009
  5. pacman

    pacman Active Member

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    An old thread popped up again in the last couple of days that touched on using CAT cable for video transmission. See http://www.controlbooth.com/forums/multimedia-projection-show-control/7955-video-via-mic-cable.html#post93382. Skip over all the mic cable stuff and go directly to the posts beginning on April 6.

    I would agree with riunexpolorer that Magenta Research transmitters/receivers will produce high quality video at much longer distance than you are running. I use Magenta gear for several video transport purposes, including your stated need from computer to projector. I also run live HD video to lobby and backstage displays. As mentioned, there are other companies who produce similar gear. For Magenta, you're probably looking at something over $500 for a transmitter and just over $300 per receiver. The receivers have a loop-through, so one transmitter can feed multiple receivers.

    There are baluns that convert video to feed over CAT cable. A client brought in some that cost about $70 each for a show. The run was about 70-100 feet. Standard definition video (fed by cameras to a small switcher) was watchable but not what I would term as high quality.

    Most companies advise against CAT6 for video because the twist in pairs results in some pairs being longer than others; see the excellent explanation by museav in the thread referenced above. You may already have CAT6 cable on hand, but CAT 5/5e is better because the twist results in more uniform lengths between pairs.
     
    Last edited: Apr 8, 2009
  6. icewolf08

    icewolf08 CBMod CB Mods

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    So did everyone miss the fact that [user]FMEng[/user] is looking for a VGA EXTENDER. This is not the same as just sending video over Cat5/6 as was being discussed in this thread. I have worked with the Geffen gear, it works very well. We never used it for any show critical applications, but we never had issues with it.
     
  7. Van

    Van CBMod CB Mods Premium Member

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    Ok,
    Being a vidiot in training, as you may be aware, I'll Bite. What's the difference ?
    Using cat5/6 as the cable for like a really long monitor extension as opposed to streaming it ? I'm missing something here, and it's not just sleep. Inquiring minds want to know.
     
  8. icewolf08

    icewolf08 CBMod CB Mods

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    There are a couple ways to send video over Cat5/6. YOu can literally just put RCA connectors on UTP cable and send video down the line. Sometimes you loose quality, but it works.

    You can buy VGA extenders or KVM extenders which convert the video signal into an often proprietary format. With a VGA or KVM extender you plug your computer's output into a box and then connect that box to a remote box which decodes the information and allows you to connect a display/projector and second Keyboard and mouse (if using a KVM device). With a setup like this you cannot route the signal through standard hubs and switches as it does not use an IP protocol, it is for point to point communication only.

    The third option are extenders that convert the signal into an IP protocol that can be routed through standard network gear. These are usually the most expensive boxes to get and sometimes you sacrifice a little quality, but they are very flexible in use because you can route them through network gear.
     
    Van and (deleted member) like this.
  9. zuixro

    zuixro Active Member

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    The VGA connector is 15 pins, but really only 5 + ground are used. Cat 5 has 8 conductors.
     
  10. Van

    Van CBMod CB Mods Premium Member

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    I hadn't thought of the KVM route for extending video. Good Idea. Right now I'm simply using 50 extensions to run my VGA signal, but my longest run is only 60some odd feet.


    Oh BTW, Hughsie ! Play Nice. keep it civil or you WILL be sent to your room.
     
  11. sk8rsdad

    sk8rsdad Well-Known Member Premium Member Fight Leukemia

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    If you Google VGA Balun you will find about 35,000 hits, many of which are retailers, manufacturers, or distributors of devices designed to transmit HF signals over twisted-pair copper. These devices are likely what you are looking for to solve your issue.
     
  12. Raktor

    Raktor Active Member

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    ..Hey look, I was part of that line that was forming.
     
  13. NickJones

    NickJones Active Member

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    I wonder how long it will take before Loki tells me I fail. :(
     
  14. NickJones

    NickJones Active Member

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    Okay, I am an idiot. Thinking back, I knew that VGA could be broken out into 3 Composite RCA's with the write adapter. Hopefully this will make me seem less like an idiot ;) it should do XGA as you wanted.
    Nick (Sheepishly)
     
  15. ruinexplorer

    ruinexplorer Minion CB Mods Premium Member Fight Leukemia

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    Actually Alex, not everyone missed the point. It was addressed by myself as the first reply and [user]pacman[/user] did so as well. Also, the thread that you mentioned also has discussion about video baluns as well as streaming video.

    I agree, we do need to stay on track with the original post which is asking for opinions on specific brands and our preferences. In my experience, not all baluns work with Cat6 cable. If you already have acess to cable (that is not run through a network) and wish to use a balun, you need to check the specifications of each individual product. I wish I could remember the brand, but one I used would only work with Cat5, not even Cat5e.

    The signal can still run into interferrence running over UTP cable. Generally the cable is not sheilded since it is designed to be run through conduit which provides the proper sheilding. If your video cable will be running near power cables, you should consider purchasing shielded cable, and even then watch for proximity to power. Also, I recommend against attaching RCA ends on UTP cable for this reason as well.

    VGA cables (D-Sub 15 connectors) usually only have 14 pins (pin 9 is the missing pin). The equipment can use all of those pins for various information of the video signal, including polling from one device to another. See here for typical pin out configuration. Cat5, Cat5e, and Cat6 are all 4 twisted pair of different specifications.

    Please, everyone, play nice. This is a learning forum. It is OK to point out errors in someone's post, but please do not mock on the error. I agree with Van in sending someone to their room. I do not want to do so.
     
  16. jowens

    jowens Member

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    I think you'll get the best quality for the price using an AVerKey scan converter, (they make a no frills for under $100.00, their quality is excellent) and run the video over standard coax (use belden 1694a) cable.
    A work-around such as using cat5/6 may work, but there is something to be said for tried and true methods that will remain reliable over long periods of time.

    Good luck!
     
  17. ruinexplorer

    ruinexplorer Minion CB Mods Premium Member Fight Leukemia

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    While I haven't used this particular piece of equipment, but in this case, it won't be of as much use to the OP. What you are suggesting will drop the resolution considerably. Most projectors can only handle lo-res over the coax connection (RCA or BNC termination). While the scan converter could take his UXGA signal down to this level and successfully pass a signal, that isn't what he's looking for. To maintain the quality of the image, the plan is to convert the signal which would normally pass on a 15-pin cable or DVI cable and pass it down UTP cable and then convert it back to its original form (this device is known as a balun).

    Thanks for your input.
     
  18. FMEng

    FMEng Well-Known Member Fight Leukemia

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    A bit more background. My project is to feed a projector from a conference table without any cabling across the floor. (What the boss wants, the boss gets.) There is a floor pocket under the table that has a conduit in concrete. It is already wired with cat 6, and I could put another cable in it. However, the run will be 270', far too long for ordinary VGA cable without major degradation.

    Pacman's mention of a possible issue with cat 6 instead of cat 5 led to some discovery. The pairs of most UTP cables are different lengths because of the amount of twist applied to each pair to prevent crosstalk. On a long cable, that results in skew, which is a time error between the colors. It's makes the colors blur. Cat 5 has skew, but cat 6 is even worse. With shorter cables, or lower signal resolution, skew is reduced. But, my cables are relatively long and I don't want anything less than 1024 x 768.

    There are two ways to prevent skew in the video. One is to use a more expensive extender with skew correction adjustment. Magenta makes such a beast which seems to outperform all the others for resolution and distance. The Magenta is several hundred more $ than most units. The other way to fix skew is to use a special, low skew cable, like Belden 7987R.

    I'm going to choose the latter. It'll be cheaper to go with the Kramer extender with Belden cable. Kramer makes a medium priced system, which I like because it has equalization adjustment and the system only has to be powered from one end. The Magenta can handle more resolution, but the Kramer will provide as much as the projector produces.

    Thanks for the leads. This was very helpful.
    Lowell

     
    Last edited: Apr 9, 2009
  19. gafftaper

    gafftaper Senior Team Senior Team Fight Leukemia

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    Complete vidiot here...

    What about a wireless solution? We've experimented with a 5.8 gigaherz wireless system from Videocomm Technologies. It works okay but my theater is so full of steel it's practacily a faraday cage so the fact it works at all is impressive.
     
  20. ruinexplorer

    ruinexplorer Minion CB Mods Premium Member Fight Leukemia

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    I assume you mean something like this? Just curious, what does this type of system set you back? How well does it handle being near other wireless communication devices (mics, cell phones, etc.)? I know most mics are below that frequency, but I think there might be some that do.

    I see that one of their selling points is that it won't interferre with wireless routers, which is good.

    The only downside, again, is that the resolution is NTSC, which is lower than [user]FMEng[/user] wanted. Wireless video is definitely gaining ground, but not quite ready for all video applications.
     

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