Splitting video live feed

[Darkness]

I've got a job in a couple of months where I need to to split a live video feed to 2x TVs, I usually just do lighting and don't have much experience with video work. The screens will be about 30-40m away from where the camera will be positioned.

 

I have a 70m network cable on a drum which I was thinking of using This adapter to convert from the video phono to rj45. My question is what is the best way to split the signal to get it to the 2nd screen which will be about 15-20m away, would something like This be adequate or would I need some sort of powered splitter with the kind of distances I'm looking at. I'm struggling to find any powered splitters for less than about £150 which is more than I would like to spend.

 

Thanks

Kevin

[Jivemaster]

Do tell what format your video comes in! Composite to HDMI or...

[Dave m]

That balun is very cheap but might do

It looks more cctv than cinema but for composite onto monitors probably ok

You'd need to experiment. Some monitors have an "in&bout" plus 75 ohm termination Or you might find that just splitting the signal works

[Darkness]

The video will come from the composite output.

 

The screens don't have an in&out just ins, would just splitting that length cable be ok, I don't know how far composite video can travel before it starts to loose the signal.

[Dave m]

I would use VDAs but I have them

It may well work just by splitting. Some monitors are better than others Unless you can buy the kit on sale or return, you need to try it

BLuns allow longer runs than composite cable

[Jivemaster]

Composite vid loses over distance and with plain splits, 100m is usually too far, you may well need to CUT cable.

[p.k.roberts]

I'd have big doubts as to whether a simple phono splitter would be any use to you; it's always difficult to tell what unknown screens are going to do about terminating the signal; there are plenty of cheapish (around the fifty quid mark) 'active splitters' (aka distribution amplifiers) in the CPC catalogue, have a look at page 66. Obviously you only get what you pay for, but a safer bet in my view.

[paulears]

With composite, the colour burst and syncs are much lower than the 1v p-p level, so small reductions in level can play havoc with the picture. You also usually get a brightness drop too. Proper monitors also have a high impedance floating input that doesn't load the line, where as a normal monitor is 75Ohms impedance, and paralleling two of them loads the line even more. Bridging inputs, if the monitors have them may well work. fixed 75Ohm monitors will no doubt be an issue - how much? Can't tell.

 

I have a broadcast camera in our follow spot box, which feeds a monitor in the lighting box, but yesterday the camera connected to the DSM monitor failed. A T piece provided a replacement picture at both monitors, but not a good one!

[sandall]

For the distances you mention I would stick with coax cable (RG59 or similar). If budget is more important than ultimate picture quality, CPC do a 1-in, 4-out video amplifier (AV11812) for about £9. It's designed for automotive use, so runs off 12v. I can't remember whether it came with a power-supply; if not you may need to bodge one. I've only used it over fairly short distances, but from a DVD source found no obvious picture degradation. Used with small 12v-powered LCD monitors it out-performed a Kramer amp costing at least 8x as much, possibly because the Kramer was overloading the monitor inputs.

 

We bought the Kramer to feed a church's projector from a DVD player, but I'm not sure it was worth the extra £70-odd.

 

 

[sandall]

See "mixing cable types" thread