splitting composite video signal

Hi all,

I have several closed circuit cameras running composite video over RG59.

The plan is to terminate these into a video sender so that I can recieve them anywhere in the house with a reciever.

However, I would also like to feed them into a PC with grabber card.

Can I just split the cable with a phono splitter or something? Or will this cause too much interferance and noise? If not, what do I need to be able to do this?

Many thanks, Lister

Reply to
listerofsmeg01
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What you probably need is a composite video distribution amplifier. Unlike most audio, video signals need to be properly terminated and buffered rather than a passive split.

However, they can be daisy chained if the termination is removed from intermediate devices and just left on the end one, but this would probably mean modifying the equipment.

This is one supplier of DAs - but there are many makes, types and suppliers so you'll have to do the searching for best value.

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You could also check Ebay for secondhand pro ones as composite isn't much in use these days in broadcasting.

Reply to
Dave Plowman (News)

I suspect there is a bit of infromation missing here. How do you display each camera on a single display, sequentially with a switcher or simultaneous with a quad split box (up to four...)

That isn't the best way to do it. You could try daisy chaining with a 75 ohm termination at the last device. But that relies on the intermediate devices having high impedance inputs, they probably are. A video DA will work but costs more.

Reply to
Dave Liquorice

The video sender sends all 4 streams on a different frequency. The receiver lets you pick a stream with a simple remote.

I'm afraid you've lost me. I am not very up on electronics. How do I tell if they have "high impedance inputs"? And what is a 75 ohm termination? Sorry for all the questions!

Reply to
listerofsmeg01

Many thanks for the info. I'll take a look on ebay :)

Reply to
listerofsmeg01

Phono splitters are evil.

As I understand it, you have several composite video cameras that are cabled back to a common location and want to view the imagery from several other locations in the house.

A possible solution is what I've done in a commercial environment where there are computers all over the place, unlike a house where you have simple television sets in different rooms. The composite video cams go in to a switcher that has both a composite video and ethernet output. The cams can be viewed on any computer on the network. Once you get the composite video into an ethernet format, you have more possibilities for distribution.

Reply to
DecaturTxCowboy

I run a pc in cellar for my cctv. Composite video signals run through cat5 cabling (via converters) to patch panel adj. The cctv software runs in full screen mode with 4 cams on screen. TV out from the graphics card goes into an RF Modulator from Maplins, this adds cctv to the main Arial input to the TV distribution amplifier. Any TV in house put to channel 8 gets cameras :)

Reply to
Tim Morley

I will say the heresy ... you could try the Y cable approach and see what you think.

It is not the best method, but it is really cheap and quick to try. You might find that it works well enough for your taste.

The impedance of the circuit is not right and a lot depends on the input amplifiers of the equipment.

The "proper" way is to use a distribution amplifier. This isolates the output that you are distributing from the inputs you are feeding and gives each input it's own good signal. Here is an example of one:

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Reply to
B Fuhrmann

Can you expand on this a bit? What do you mean by "switcher"? Is this a device that cycles through the various inputs on a timed basis? In what format is the video put on the wire? Is it some standard like MPEG-4?

The whole point of the split is to get imagery to my PC network too (and to the Internet), but the quality is not brilliant, and I really wanted to have an easy to access good quality source on my telly - hence the two seperate systems.

In my previous house I used to have the grabber PC use my telly as the console. This worked ok, but it meant your had to chose camera sources via a wireless mouse and keyboard which was a bit clunky.

Reply to
listerofsmeg01

Hmm. This is interesting, but I take it all your TV's are hardwired to the DA with coax?

Wiring is not an option in my case, but your use of an RF modulator is intriging. Can you get video senders that send RF signals do you know? With this I could have each camera with its own RF mod putting it on a different frequency. This way I could in theory transmit as many cameras as I wanted on the channel. The 4 channel limit has been bugging me a bit :-/

Reply to
listerofsmeg01

Any video card with RF input can fit in your PC and you can modulate the cameras with an RF modulator. We use the Channel Master units in bars, but the little 3 channel unit that shows up on eBay will do in a pinch and modulate 10-15 TV's. Here we give it UHF channels 65,67 and

72 and all tv's can tune it.

Try

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a source of RF modulators.

Carl Navarro

Reply to
Carl Navarro

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