Live Video Feed
 

I've been providing live video/audios feeds for choral concerts. Until recently, I was sending the audio and video signals from my wide camera down a 100' stage snake via the 1/4" returns and then converting the signal to coax from the snake box to the TV (usually in a classroom behind the auditorium). Needless to say, coax is difficult to roll out, tape and then pick up again. Not to mention the additional bulk added to equipment load.

To try and avoid this and to improve picture and sound, I decided to switch to RCA cable. Without thinking, I bought two 100' (red, white, yellow) cables that were pretty thin. Well, in case you haven't guessed by now, the video at the end of the run was black & white and extremely fuzzy. The audio seemed fine, however.

My question is, would a heavier grade video cable provide the needed impedence to keep a good signal for up to 200'? One such as this one at B&H:
http://www.bhphotovideo.com/c/product/546852-REG/Pearstone_VARC_1100_RCA_Male_to_RCA.html
Any advice or suggestions would be greatly appreciated.

Rey

Re: Live Video Feed
 

No. You need to buy a quality RG-59 BNC cable (you can put BNC to RCA adapters at either end). You can run up to about 300' on a good video cable but beyond that you'll need a video DA. You'll notice a quality improvement in the video immediately over your current system. Markertek - Audio and Video Equipment - Professional Broadcast Studio Equipment has many great cables for this purpose. As with all things video; you get what you pay for.

Re: Live Video Feed
 

Hi Rey,

While I haven't personally tried them, do a search for "Video Balun" - these are small, inexpensive devices that convert video to Cat-5 cable. You put one Balun at each end of the run, converting TO and FROM Cat-5, and this is supposed to deliver a clean signal over longer distances.

Jeff Pulera
Safe Harbor Computers

Re: Live Video Feed
 

Rick,

By the same token, could I simply install BNC connectors onto the coax cable that I already have? I'll take a look, but I do believe that it is RG59.

Nevermind. My coax is RG6.

Re: Live Video Feed
 

Hi Guys, a few months ago I was asked to provide a live video feed of an event to another room at the venue. I used an "CAT5 HDMI Extender" like Jeff mentioned. For under $100 I ran HDMI 1080p with audio for about 200 feet. It was really slick and I got compliments on how great the video looked at the other end.

If your cam outputs HDMI it seems like a really great way to get audio and video where it needs to be, and with the right version of the equipment I think you can go over 350 feet. They also make composite, component and audio versions of the CAT5 extenders.

Re: Live Video Feed
 

Jeff,

I've been looking over these. Do you happen to know if the ones showing up for around $15.00 a pair is sufficient or is there something else I should be looking for?

Re: Live Video Feed
 

Part of the reason for using heavier/high quality cables is that they are more durable and have the correct impedance for video with very little signal loss (a standard video signal is only 1 volt). RG6 or CAT 5 is fine if it goes under a raised floor, in a wall or in the ceiling. One good cable yank or spiked heel on the cheaper cables will end your video feed. Same with baluns; cheaper = failure.

Re: Live Video Feed
 

I've found a pair of passive composite video baluns UTP AV to Cat5 on Amazon for $36.95. Good reviews and they carry both audio and video.

As far as Cat5 cable, I was aiming for something mid-pack. Not cheap, but not underground top of the line, either.

Re: Live Video Feed
 

RG-6 and RG-59 are just general cable types. There are numerous specific RG-6 cables made by different manufacturers, and numerous specific RG-59 cables as well.

Both RG-6 and RG-59 are the correct 75 ohm impedance needed for video. (Other coax types, such as are used for test equipment, and RF gear such as transmitters and receivers, are usually 50 ohms and will work very badly for video systems.)

In general, RG-6 will have less loss than RG-59, so you're actually better off with RG-6. (RG-59 is typically around 1dB per 100' at 10 MHz; RG-6 is typically around 0.75dB per 100' at 10 MHz. However, you need to know the exact manufacturer & cable part number to find the exact loss figures.)

In general, RG-6 cables are a larger OD than RG-59 cables, so you need a different size connector. You won't be able to stuff RG-6 into an RG-59 crimp connector.

Your local TV cable system almost certainly uses RG-6. (It has lower loss and better shielding, compared with RG-59. RG-59 is old hat these days.) With a little luck (or a few mugs of an adult beverage) you might be able to bribe the local cable installer to install the correct connectors for you.

FWIW, RG-11 is even better than RG-6 (about half the loss); however, it's a much larger diameter and is much harder to work with. You don't want to mess with RG-11 if you can avoid it.

Re: Live Video Feed
 

Thanks, Greg. I decided to abandon the coax because it is so difficult to tape down and maneuver. I'm going with composite to Cat6 baluns. Although on the cheap end (the pair is $36.95 shipped), the manufacturer assured me that there would no noticeable loss at 250' (my longest run) and their return policy allows returns within 30 days with no restocking fee.

Couldn't hurt. At worst, I'll be left with 200' of red Cat6 that I can sell on Craigslist. :)

Rey

Re: Live Video Feed
 

Rey,

I've run a lot of RG-59 on temporary event projects, and never had much trouble taping it down. I recall running it at the intersection of a wall and floor, and it pretty much laid in that 90º vertical corner on its own, just needed a 6" piece of gaff tape every several feet. I guess your experience might be different.

Most 75-ohm cable has a solid center conductor, which makes it a bit stiff. 50-ohm cable is available with a stranded center, which makes it even more flexible. I haven't tried running video through 50-ohm cable, in theory there would be a small bit more loss because of the impedance mismatch. Of course you want to avoid any cable with a foil shield, because that is harder to work with.

I wish you well with the video baluns. I have not tried them and can't predict much. I do know (from my experience with RF) that every balun has some amount of loss; and of course the CAT6 will have some loss too... but I have no idea how much loss (measured in dB) at video frequencies, and that's the real question. It would be interesting to try an actual test. (Of course it's not as much of an issue with audio, where you have variable-gain amps in the circuit. But video expects a given level and there's frequently no easy way to compensate for cable loss, at least not in anything other than high-end studio equipment.)

Please post back and let us know how everything works out, I'm sure other folks are curious, as I am.

Re: Live Video Feed
 

The last of the components finally arrived today!

I was able to use the a/v output from one of the CX500V's to R/W/Y RCA plugs into a balun, through 200 feet of Cat6 cable, into another balun and outputting back to R/W/Y into a TV. Great picture and sound! Seems to work perfectly as advertised. :)

Re: Live Video Feed
 

I'm glad to hear you solved the problem. 200 ft. is a very respectable run, so I think you've found (or confirmed) something important about these A/V baluns.

Thanks for the report.

Re: Live Video Feed
 

I'm actually picking up two additional 50' cables for any situations that warrant between 100'-150' or up to 300'. The company said that there should be no signal degradation even at 300' (the baluns are rated up to 500'), so I'll check back in here when that's confirmed.