2.02.2009

Modular Cat5 A/V Cables










Price of cables got you down? To hard to get that VGA cable exactly where you need it? In this mod I’ll take standard Cat5 cable, yes the stuff you network your computer with, and show you how to make quick and dirty modular A/V cables. They look somewhat professional too.

For Christmas my dad received a nice new BIG LCD TV. Wanting to get the most out of his new TV and move into the HTPC age the only thing standing in the way of getting the computer connected was cabling. With no room to house a computer near the television, cables would need to be run nearly 30 feet in order to reach the display. As you may know cables of this length can be expensive and VGA cables are quite thick to try and run through a wall. So thinking like a true modder, copper wire is copper wire.

I had a few different ideas of how to connect the computer to the TV. There are a number of inputs available, the two I was mostly concerned about were the VGA and the component inputs for video. While researching the pin-out of your standard VGA cable I came across this site. My first thought? That’s exactly what I’m trying to do.

While mounting the television, we went ahead and ran two cat5 cables downstairs and placed a wall plate behind the TV. This is where the modular part comes in. The wall plate has two standard cat5 punchdown blocks installed which will allow me to make whatever type of cable I need for the TV and add an RJ45 connector to the end.

VGA CABLE

VGA Connector and hood.

The first cable I decided to make was the VGA side to connect the PC. All that’s needed is a strand of network cable, a male 15-pin HD D-Sub connector (VGA Connector) along with the metal hood, and a little soldering skill.

Cat5 wire with outer shielding removed.

Cat5 stripped and ready to be soldered.

First step is to prep the network cable. Cut the outer shield from the cable about two inches back and then use some wire strippers to prepare the wire pairs for soldering.

Connector and cable ready to be soldered.

Soldering can be a little tricky if you don’t have a set of “helping hands” to hold the connector and wire while you work. I would also suggest soldering the middle row of posts first, it’s a little easier.

The pinout for the VGA Cable is:

VGA Connector

  1. red video — connect to Orange
  2. green video — connect to Green
  3. blue video — connect to Blue
  4. ID2 — no connection
  5. ground — no connection
  6. red ground — connect to Orange/White
  7. green ground — connect to Green/White
  8. blue ground — connect to Blue/White
  9. key pin — no connection
  10. sync ground — no connection
  11. ID0 — no connection
  12. ID1 — no connection
  13. Horizontal Sync — connect to Brown
  14. Vertical Sync — connect to Brown/White
  15. ID3 — no connection

Finished soldering!

After you get started, it doesn’t take long to finish up the soldering. As you may have noticed I decided to add a little bit of shrink tube around the leads to make things look neater.

Finished VGA to Cat5 cable.

The last step is to screw the hood assembly together and add a standard RJ45 (type B) connection to the end. This cable is ready to plug into the computer and head straight to the wall jack.

Component Cable

I originally thought I could adapt the VGA signal from the computer to a component input for the TV. I found that I was mistaken. It’s possible, but you need an extra device called a scan converter and I really didn’t want any extra devices in between. Of course, I didn’t discover this until I had already made my component end. (I wound up making a second VGA cable to run to the TV.) But, if you’re just wanting a component cable here’s how you make one.

Metal Phono Plug with solder leads.

You will need three RCA phono plugs for this cable. I found some rather cheap ones here. You can get cheap looking plastic ones, but I would rather spend the extra 10 cents and get the cool metal ones. Just like in the above cable, you will need to prep your network cable for soldering by stripping the wires.

The pinout this time is:

  • RED Positive (PIN) — Orange
  • RED Negative (Shield) — Orange/White
  • BLUE Positive (PIN) — Blue
  • BLUE Negative (Shield) — Blue/White
  • GREEN Positive (PIN) — Green
  • GREEN Negative (Shield — Green/White

Soldering the phono plugs.

Again, having a set of helping hands really helps the process. These plugs are really easy to solder compared to the VGA type connector. I suggest soldering the center lead first. Otherwise you might run into a wire length problem. (I know from my first attempt.) The other lead allows you to stick the wire through a small hole and solder it directly to the flat plate. Be sure to put the shield and shrink wrap on before soldering the leads, it’s no fun having to unsolder something when you think you’ve done such a good job.

Finished component cable

Again, you finish up by crimping the RJ45 connector to the end. The finished product is a fairly nice looking modular component cable. I left the brown pair looped around the cable, just in case I need to add a connector in the future.

AUDIO Cables

Audio cables are just as easy to make as the component cables, in fact they’re identical. Only this time you only need two phono plugs instead of three. That is if you’re just looking for simple stereo sound. If you’re going for multi-channel audio you’ll need a few more phono plugs, but keep in mind you only have four pairs of wires to work with. That translates to four total sound channels. Although if your devices permit a digital coaxial input/output, then you could just use the brown pair from the previous cable.

Stereo audio cables.

The pinout I used for the stereo audio cable was:

  • RED Positive (PIN) — Orange
  • RED Negative (Shield) — Orange/White
  • WHITE Positive (PIN) — Green
  • WHITE Negative (Shield) — Green/White

As you can see, making custom cables doesn’t have to be difficult or expensive. They can be pretty much any leangth you want them to be, up to around 50 feet. With the modular ability of the RJ45 jacks, you can estimate exactly how any pairs of wire you need to complete your home theater connections and take care of all your wiring with the cables I’ve shown you and they’ll look neat and tucked away behind your equipment. So, don’t ever let that sales rep. talk you into over priced Monster Cables!



3 comments:

  1. Anonymous17.9.09

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  2. In the case of VGA to CAT5, I believe pins 5 and 10 should also be connected to Blue/White as pin 8 is to ensure proper grounding and improved resolution on TVs or extended monitors.

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