Video over audio wire???

[Plus4dB]

There are several products that will send composite video over CAT 5 wire with very little signal loss or artifacts, but does anyone know if it is possible to send composite video over regular analog audio cable? There are several runs of single-pair (balanced) shielded audio cable (22g) and I only need to go a short distance, maybe 25 to 30 feet. If I use a CAT 5 video distribution product and just break-out the twisted pairs to audio pairs, will this work?
Thanks,
Mark

[gullfo]

it might be more of a problem of interference to other signals than working or not working. i'd compare impedance of the cables but the shielded cable seems like it might be workable. you might post this question into Aaron's wiring forum on this site.

[Plus4dB]

Thanks, Glenn.
Also, do you think it is more likely that the video will cause noise in the audio, or the audio will cause artifacts in the video?
I will also post into Aaron's wiring forum.
Mark

[John Mackniskas]

I'm not sure what you need it for but I just bought a 25 foot VGA/PS2 cable ($42.00) and was able to move my noisey CPU out of the control room and into my machine room making my control room dead silent. This company that I bought the cables from guarantees no signal loss, distortion or ghost for up to 100 feet. They also have just video cable as well.
The company name is Video Products Inc and their phone number is 800-626-7801, But I was able to complete my order online in minutes. http://www.vpi.us/
I hope this helps.

[Soundman2020]

but does anyone know if it is possible to send composite video over regular analog audio cable?

Not directly, no. Impedance mismatch, shielding, etc. Or let me put it another way: the signal might get through, but it will be noisy, poor quality, and radiating all over the place. Not recommended.

If I use a CAT 5 video distribution product and just break-out the twisted pairs to audio pairs, will this work?

Nope. For the same reason. It's called "twisted pair" for a reason: the "twist" gives it the electrical characteristics that it needs to carry the signal correctly. If you use another kind of cable, without the "twist", then the impedance will no longer match, and you will have issues with power loss, reflections, noise, etc.

Video signals are up in the megahertz range. Audio signals are down in the low kilohertz range. Square peg, round hole. Sure, with brute force you CAN smash a squer peg into a round hole, but the result won't be good either for the peg or the hole!

Do yourself a favor, and either pull a piece of coax through the duct, or use a wireless link of some kind. Some wireless links can handle video. It all depends on what you need...

- Stuart -

[Plus4dB]

Thanks for the reply. Pulling new wire is not an option - everything is closed up and packed tight.
I guess wireless is my only option at this point. Anyone know of a good solution for transmitting wireless video through fiberglass and several layers of sheetrock and soundboard?

[Soundman2020]

What kind of video? Plain old vanilla composite NTSC? No high quality video required?

Maybe these might work:

http://www.supercircuits.com/Wireless-D ... deo-Links/
http://www.mindspring.com/~stancom/micwav.html
http://www.wirelessvideocameras.com/

I have no idea how good they are: Just a few that came up on a search.

Sheetrock and studs have little effect on signals over that distance. Anything basic should work.

There are also some products that use your house electrical wiring, but I don't think I'd like to do that in a studio.



- Stuart -

[Plus4dB]

Thanks, Stuart.
Yes, just plain old composite NTSC video will do. They want to be able to send a live camera feed from the live room to the control room and also be able to send pre-recorded video program (like a Quick-time video from a computer) from the control room to the live room. They may have to switch transmitter and receiver depending on which way they are sending, but these should work.
Thanks,
Mark