# VGA over Cat 6



## FMEng (Apr 8, 2009)

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,


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## ruinexplorer (Apr 8, 2009)

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.


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## NickJones (Apr 8, 2009)

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


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## Hughesie (Apr 8, 2009)

NickJones said:


> 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. Alternately you could consider scan converting it to RCA/composite then you can run it through Cat5.
> Nick


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.


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## pacman (Apr 8, 2009)

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.


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## icewolf08 (Apr 8, 2009)

FMEng said:


> 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,



So did everyone miss the fact that FMEng 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.


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## Van (Apr 8, 2009)

icewolf08 said:


> So did everyone miss the fact that FMEng is looking for a VGA *EXTENDER*. This is not the same as just sending video over Cat5/6.....


 

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.


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## icewolf08 (Apr 8, 2009)

Van said:


> 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.



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.


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## zuixro (Apr 8, 2009)

NickJones said:


> VGA is 15 pin (if memory serves correct) and Cat5 is 5 pin.



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


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## Van (Apr 8, 2009)

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.


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## sk8rsdad (Apr 8, 2009)

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.


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## Raktor (Apr 8, 2009)

Van said:


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



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


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## NickJones (Apr 8, 2009)

Raktor said:


> ..Hey look, I was part of that line that was forming.


 I wonder how long it will take before Loki tells me I fail.


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## NickJones (Apr 8, 2009)

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)


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## ruinexplorer (Apr 8, 2009)

icewolf08 said:


> So did everyone miss the fact that FMEng 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.



Actually Alex, not everyone missed the point. It was addressed by myself as the first reply and pacman 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.


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## jowens (Apr 9, 2009)

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!


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## ruinexplorer (Apr 9, 2009)

jowens said:


> 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!



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.


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## FMEng (Apr 9, 2009)

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


pacman said:


> 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.
> 
> ...


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## gafftaper (Apr 10, 2009)

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.


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## ruinexplorer (Apr 10, 2009)

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 FMEng wanted. Wireless video is definitely gaining ground, but not quite ready for all video applications.


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## museav (Apr 10, 2009)

This thread seems to cross several topics! Ruinexplorer provided a nice link to the connectivity in a VGA connector and if you note, the relevant video signal information is red, green, blue, horizontal sync, vertical sync (or a composite sync instead of separate H and V) and the related grounds. This is where the common term RGBHV comes from, the actual video signal content in a typical VGA connection. Those are the signals that typically have to be transmitted.

You can transmit those signal using VGA cable, which if per standard practice uses mini coax for the red, green and blue signals and twisted pairs for the sync signals. However, the small gage cable used typically results in higher losses and thus limits the length possible without signal degradation. It is common in installed systems to use a RGBHV cable that uses five separate coax cables bundled in one overall jacket. This is available with a variety of coax sizes and quality and can allow for much loner runs.

The most common "VGA" over UTP solutions simply replace the coax with twisted pair cable, running both sync signals on one pair. The baluns or interfaces do not do much other than handle to physical connections, impedance matching, etc. necessary to transition from one physical type of wire to another. You are still sending an analog signal on the wire, just using a different wire.

A step up from that are active interfaces that incorporate signal processing such as gain, EQ and skew compensation. These may also process the signal such that a single 4 pair UTP cable can support mono or stereo audio and in some cases even serial control signals as well as RGBHV video signals. But it is still analog video (and possibly audio) being transmitted and still simply a matter of a different physical cable versus a different form of signal.

It is a completely different subject when you get into converting the analog VGA/RGBHV video signals into some other signal format for transmission, be it an Ethernet data stream or some proprietary format or whatever. Video over a network is very different than video over UTP.


Always be very careful when comparing video over UTP device specs! There are few, if any, standards and a lot of very questionable practice in defining the performance of these devices. When a product identifies an X foot range, how is that determined? What signal (resolution, refresh, etc.) does it represent? What determines the result being acceptable?

As far as video over UTP devices, I have also had very good luck and support from Extron and FSR. While I have had very good experiences in the past with Magenta Research, I was out on a project site yesterday where we experienced a high number of failures with some of the new Magenta products. I am hoping this is an anomaly and not a change in the quality I've come to expect.

I have yet to find a reasonably priced wireless transmission solution for higer res graphics that also worked well with motion images.


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## gafftaper (Apr 10, 2009)

ruinexplorer said:


> 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 FMEng wanted. Wireless video is definitely gaining ground, but not quite ready for all video applications.



Yeah that's the one. I think we paid around $350 for a kit with transmitter and receiver. We use it for our Infrared stage manager's monitor camera (Sony handicam in nightshot mode with a S4 par filtered to only produce IR). It's nice because I can move the camera anywhere in the theater and not worry about cable. On the other hand there's always a good deal of wiggling antennas on both ends to get the picture perfect... but again that may be more due to my theater's steel catwalks and steel studs in the walls. I would be curious to see how it does in a big proscenium house where it's got an open shot from front to back of house. 

It doesn't seem to pick up cell phone interference but it does clearly matter how close the receiver is to the monitor and other electronic devices in the booth. I have it right against the window and as far away from other interference as possible. Once we get it tweaked it produces a suitable picture for our backstage tech needs... but it wouldn't be acceptable for something like a lobby feed.


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## FMEng (Apr 10, 2009)

Based upon what I have read, everything Museav says is right on. Baluns can convert the signal to a different cable type, like UTP. Adapters can convert it to a group of bigger, individual coaxial cables. 

A different cable type will help it go further because those cables will have less high frequency roll-off than the regular VGA cable. But, they too suffer from roll-off, it just takes a longer distance for it to take effect. That's where the extenders come into play. They have equalization and gain to overcome the normal roll-off properties that every cable has.

It's fairly easy to get NTSC to go long distances with good cable. But, higher resolution, like XGA, is tougher to do.


museav said:


> .
> The most common "VGA" over UTP solutions simply replace the coax with twisted pair cable, running both sync signals on one pair. The baluns or interfaces do not do much other than handle to physical connections, impedance matching, etc. necessary to transition from one physical type of wire to another. You are still sending an analog signal on the wire, just using a different wire.
> 
> A step up from that are active interfaces that incorporate signal processing such as gain, EQ and skew compensation. These may also process the signal such that a single 4 pair UTP cable can support mono or stereo audio and in some cases even serial control signals as well as RGBHV video signals. But it is still analog video (and possibly audio) being transmitted and still simply a matter of a different physical cable versus a different form of signal.
> ...


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