S-Video and USB over CAT5
My 1980s Videophone project is a little lacking in the cable area. The video display utilizes a coax cable connection to the composite video out on the server, using F to RCA connectors. Since the server is in the basement, using a cable TV connection I have from my office to the basement works great for connecting the video display to the server. The wiring I needed was to connect the S-Video camera on top of the display (a Commodore 1702 monitor in my office) to the server in the basement. I had run a 10 meter stretch of S-Video cable to the basement, but that didn’t cut it. I wanted to use those network jacks I have in my office next to the cable TV jacks. Something came to mind:
Tony's Wiring Rule # 1: You can get almost anything to run over CAT5.
S-Video would be a great candidate for going over CAT5 (as opposed to coax,) because S-Video can run unsheilded. I have some CAT5e jacks that I’ve wired to my office from the basement. Since S-Video only uses 4 wires, and CAT5 has 8 wires (4 pairs)… why waste the other 4 wires in the CAT5 cable? It would be great to hook up a keyboard and mouse to the server in the basement, and have them near the 1702 monitor. USB uses 4 wires and can also run unsheilded…
I’ve read that S-Video can transmit up to 15 meters (50 feet), and USB up to 4.5 meters (15 feet) before needing a USB hub as a repeater. I realized I’ll probably be pushing the distance limits of these technologies over my 10 meters of CAT5 between the basement and my office. Since I am running the signals over twisted pair, I should be able to get some extra distance… but normally S-Video and USB wires are shielded, so I may get a lot of interference.
This is how I’ve wired up all the connectors, making two sets of cables, one for each end. (Click on the diagram to zoom in.) The only exception being one cable set having a Type B USB connector, to connect to a USB hub in my office. I used some surplus USB, S-Video, and CAT5 cables. I stripped all the wires, tinned them with a little bit of solder, and soldered each wire together. I also insulated each soldered connection with electrical tape. On the first test, I had to re-crimp one RJ-45 connector and re-solder a connection due to connection problems. Oops! Testing the two cables with a barrel connector (so I could plug both RJ-45 connectors together) proved to work.
After plugging one set of cables into my server and patch panel, and the other set in my office (a 10m run), the S-Video worked! Unfortunately, though, the “overcurrent” lights were illuminating on the USB hub connected to the office end. It looked like the USB port on my server’s A-Bit BP6 wasn’t supplying enough current. Instead of connecting the CAT5 cable converter directly to the server’s USB port, I plugged the cable converter into a powered USB hub. The USB hub would hopefully have more current than the server’s USB port. The USB hub was then plugged into the server’s USB port. With the two USB hubs, one on each end of the connection, voila! Enough current. I used USB 2.0 hubs, too… I only tested a USB mouse, but I’m not sure as to the max data rate I can get.
Who says you have to pay $100 in baluns to do this kind of thing? Now I can have a USB keyboard/mouse and S-Video camera next to my 1980s videophone. 
Update: I tested USB 2.0 traffic over the adaptor cables, using USB 2.0 hubs and a Plextor DVD recorder. Unfortunately, reading a DVD movie with USB 2.0 doesn’t work with the adaptors. Using a USB mouse and keyboard works fine, though.
February 20th, 2007 at 9:42 pm
I have did something like this with S/Video about 4 years ago now. I ran a Ethernet S/Video with stereo sound. It’s ran in the wall with wall plates.
I made one again but this time I got a S/Video with stereo cord but it in half and put female Ethernet jacks on it. I can use a long Ethernet cable to go stereo and S/Video. The Ethernet cable is about 100 foot long and the sound and video are super.
I just got a photo of one half of the cable and put it up at:
http://i93.photobucket.com/albums/l41/RaymondDay/My_S-Video_Stereo_Ethernet.jpg
-Raymond Day
April 30th, 2007 at 11:02 pm
Cool website! I was wondering if this s-video over Cat5 was up to snuff! IT IS! applying the concepts listed, I wired a DVD player to an LCD projector along a 125 foot streatch. Using some left-over Cat5 from my ‘network’ installation days, I soldered both ends with an S-Video connector available from our local Radio Shack store. The cable actually works! This successful cable installation saved our church some serious bucks (based on some equipment recommendations from local Audio/Video suppliers).
Thanks.
July 10th, 2007 at 4:37 pm
I was thinking about and it seems that you can actually put S-Video, L+R Audio and USB on 1 Cat5 cable. Since S-video has 2 ground, L+R Audio also have 2 ground and USB has 1 ground. So that leaves actual wiring as follows:
1 – Ground (all ground wires)
2 – USB VCC (+5 VDC)
3 – USB D- (Data -)
4 – USB D+ (Data +)
5 – S-Video Y (Intensity (Luminance))
6 – S-Video C (Color (Chrominance))
7 – Left Audio
8 – Right Audio
Wondering if that would work or will it damage my stuff having all the ground wires go to one wire. I wouldn’t think so as they are all going to ground anyways. What do you think?
July 10th, 2007 at 4:39 pm
Hi Max,
You *probably* could do that, and you *might* not damage anything, but the length of your run would decrease. There might be grounding issues, too. The gauge of the single ground wire probably would not be enough to support all signals. If I were you, I’d run two CAT5 cables. One for S-Video and audio, and the other for USB. That way, each signal (or voltage supply) has its own ground.
The only way to find out is experiment! Best of luck.
Tony
October 8th, 2007 at 1:22 am
Hmmmmm…..To ensure USB signal ‘purity’, and seeing as how you would have power available at the other end of the line, couldn’t you make a USB-only Cat5 as D-/Gnd, D-/Gnd, D+/Gnd, D+/Gnd, and get the five volts from a powered USB hub at the far end?
October 14th, 2007 at 8:46 pm
Hi DeadlyDad,
That config would probably be better and afford a longer distance. If anyone tries this config and has better results, please write in!
Tony
January 7th, 2008 at 12:37 am
Hi Guys,
I have run component, audio, composite and VGA signal over cat-5 myself. I was a little surpice I actually was able to run VGA signal from my home office to my garage which is about 120′ run.
This will be my first time to test and see how far USB will run over cat-5.
I bet is going to be 150′ for a self power device like my joystick for flight simulator.
I will lwt you know how it go
Tony
April 21st, 2008 at 9:56 pm
Using a USB DAC about 40 ft away from my PC passing USB over CAT5 (the DAC only needs USB 1.0 bandwith). At first, I connected each 5V, ground, D+ & D- on a separate twisted pair (i.e. each of the 4 twisted pairs had an unused wire). I kept loosing the signal…
I then changed tactics and put D+/D- on a single twisted pair and 5V/Ground on another. It worked perfectly without disconnections (been testing for over 48 hours). So I guess its better to keep the twisted pairs “as is” to avoid EMIs.
Silmara
April 22nd, 2008 at 7:51 pm
Silmara,
Thanks for your test info! Alternatively, when you put +5V, GND, D+ and D= on one conductor of each pair, the “other conductor” for each pair could’ve been GND. That way, you would be using three pairs — +5V/GND, D+/GND, and D-/GND, similar to what DeadlyDad (above) suggested.
Tony
July 8th, 2008 at 2:03 pm
OK guys, you have lost this old man on some of your extending USB ideas. I’m trying to run USB webcams over cat5. If I am reading all the info right, I need to hook the webcam to a powered USB hub, connect the hub to CAT5 using an adapter, run my cat5, at the other end I repeat the process except the second powered USB hub connects to my PC. Am I close? I already have some ethernet to USB adapters I picked up through an online auction site but haven’t been able to get the camera to work. I tried a single powered USB hub but didn’t think about trying one on each end. I am VERY new to USB and I didn’t realize the distance limitations until I got started. Thanks, Jerry
July 9th, 2008 at 9:34 pm
Hi Jerry,
You’re right — what I suggest is that you connect a powered USB hub to your PC and to your webcam. Then, you join the two powered USB hubs together with the CAT-5 cable (and the suggested CAT-5 to USB adapters). The powered USB hubs on each end seem to help increase the distance a bit, at least for around 30 feet. Just make sure your CAT-5 run is less than 30 feet with this homebrew method!
Tony
July 30th, 2008 at 3:42 pm
Hi everyone. You can´t put D+ and D- in separate pairs because they are symmetrical. If you do so, you are going to pick up lots of external noise and loose communication as Silmara confirmed. So as long as you keep D+/D- in the same twisted pair, it will “work”.
Tony, was your cable STP or UTP (shielded or unshielded)? Did you tested other devices other than a webcam? i.e. a pen or disk to see how fast it goes?
Rex.
July 30th, 2008 at 3:46 pm
“a differential pair” instead of “symmetrical”
loool
January 16th, 2009 at 2:32 pm
let’s try this config:
usb device -> powered usb hub -> D+/D- on the cat5 cable -> powered usb hub -> PC
and because we have 4 twisted pairs, we can connect data lines to each of them
the resulting resistance would be R/4, maybe the signal/noise ratio would be better
the power lines have no other function, than supporting power, and the powered usb hubs can do that
March 6th, 2009 at 12:23 pm
Hi Tony
I have purchased s-video baluns, however I am very interested in what you have achieved. I only need to send s-video over cat 5, no audio or
usb is required. the max length I am looking at is around 30M, forgive my
ignorance but would your solution suffice?
March 11th, 2009 at 11:41 am
I just bought a Cables Unlimited USB-1370 at Fry’s for $40. It lets me run USB up to 150 feet over Cat5 cable – no hubs needed. I think the biggest problem with extending USB is the clocking; you don’t run out of current after 15 feet as much as you start to lose clock sync because the round trip delay gets too large. The USB-over-Cat5 converter has electronics in it that re-clock the signal (probably at a lower rate). Anyway, so far I have only tested this solution with 50 feet of Cat5 and it worked beautifully up to about 3 Mbps.
March 11th, 2009 at 6:59 pm
Hi Kevin,
If you look towards the top of the comments list, you’ll see that A.J. Morales was successful with a 125 feet run. That’s 38.1 meters. So, 30 meters should work!
Tony
July 22nd, 2009 at 5:47 pm
Check out Leviton Inserts.
They have inserts for wallplates that will do S-Video, RCA, USB over Cat5.
June 1st, 2010 at 11:00 am
It’s normal that the USB mouse and keyboards works on your setup, because USB mouse and keyboards are not using USB, but PS2 mode of the USB port. Each USB port can do USB or PS2 serial.
But for the real USB device, you can’t do more than 5 meters without active repeaters because of the 26 nS Acknowledging timeout delay of the transceivers. (26 nS = about 5 meters of wire).
Pass this delay, the USB tranceiver is already in the Timeout process when it receive the ACK from the other side.