Video Balun quality
- Thread starterechellis
- Start date
Cat5/video baluns?
Honestly I haven't had a ton of luck with them (at least on any level other than high-end). I've been interested in using them in 300'+ runs for composite video sends to Breakout rooms. Forget the passive baluns, they are pretty much useless at that length. I have also used active baluns that are powered on one or both ends and have had better luck with those. I have used the high-end extron units, and they are more than acceptable, but cost a small fortune.
Maybe someone has more experience with a wider product range.
Honestly I haven't had a ton of luck with them (at least on any level other than high-end). I've been interested in using them in 300'+ runs for composite video sends to Breakout rooms. Forget the passive baluns, they are pretty much useless at that length. I have also used active baluns that are powered on one or both ends and have had better luck with those. I have used the high-end extron units, and they are more than acceptable, but cost a small fortune.
Maybe someone has more experience with a wider product range.
I used to send our greenroom feed straight over CAT5e, no baluns, just simple adapters I threw together in 5 minutes. The video quality at 100' was still perfectly usable for our projector, and at 200', which was backstage, the video was still acceptable for display. The only issue I ran into was the impedance mismatch, which shows up as ghosting. But since this is for a greenroom feed, that shouldn't be too much of an issue.
I have used a variety and on the lower end, it starts to depend more on the cable for a good signal. I used one that would only work with Cat-5, not Cat-5e or Cat-6 cable which ended up being a real pain when we bought a spool of the wrong cable. Since Ethernet cables are usually run in conduit, they don't worry about sheilding, so you need to be aware of that (you probably won't have it in your budget to purchase shielded cable). Overall, I have had great success with them and they have made my life easier on many occassion.
I think I am just going to get a pair and try it. I have a box of cat6 cable that I can run it over. So hopefully it will work a little better over that then CAT5e
Just like anything, there is a wide range of products, prices and performance. I personally use 'balun' to refer only to passive, transformer based products and 'interface' for powered or more advanced products. One of the biggest factors in performance is what signal you are running. You may be able to run simple composite video long distances with little problem while running higher resolution VGA/RGBHV or digital signals such as SDI, DVI or HDMI typically have greater much greater distance limitations and other considerations.
Most microphone and other cables are also run in conduit yet there are still good reasons in some cases to use shielded cables. Part of it is electrical versus magnetic interference and part of it is that you can still have a number of radiating cables within a single conduit.
For many video applications, CAT5 may work as well or better than CAT5e or CAT6. It is a factor of the twist rate of the pairs. The tighter twist rates of CAT6 mean better rejection of noise but because the twist rates also vary for each pair this also results in greater differences in length between individual pairs, which causes what is referred to as skew for signals that use more than one pair. So CAT6 may allow longer runs due to improved resistance to noise but for those long runs with many signal types it may then also require interfaces with skew compensation.
Most microphone and other cables are also run in conduit yet there are still good reasons in some cases to use shielded cables. Part of it is electrical versus magnetic interference and part of it is that you can still have a number of radiating cables within a single conduit.
For many video applications, CAT5 may work as well or better than CAT5e or CAT6. It is a factor of the twist rate of the pairs. The tighter twist rates of CAT6 mean better rejection of noise but because the twist rates also vary for each pair this also results in greater differences in length between individual pairs, which causes what is referred to as skew for signals that use more than one pair. So CAT6 may allow longer runs due to improved resistance to noise but for those long runs with many signal types it may then also require interfaces with skew compensation.
