540tvl cameras over RF

[lmaugustin 0]

Is anyone distributing hi-res (540tvl) CCTV video out over CATV?

 

I have an existing installation of hi-res CCTV cameras (540tvl NTSC output) and would like to distribute the video over CATV channels to standard TVs throught the building. Each camera would be modulated onto a different CATV channel.

 

Can I use a standard RF modulator (e.g. the ChannelPlus 54x5 series of RF modulatiors)? Will the ChannelPlus be able to handle the 540tvl output cameras? If not is there any equipment that will do this for me?

 

Thanks,

 

Larry

[rory 0]

Modulated video will be much lower res regardless of the camera, coax, or amplifiers, but the only choice you have if you cant run a separate cable to each TV. On a hi def unit it is a little better, but not that noticeable.

 

Best quality is to use a multiple output distribution amp and run a separate cable to the A/V input on each TV.

 

If its coming from a PC DVR and going to LCD HD TVs, then best quality is to use some kind of DVI distribution to the LCD TVs HDMI Input.

Edited September 1, 2007 by Guest

[scorpion 0]

Rory hit this one right on the head!

[lmaugustin 0]

Thanks. I was having some problems with the ChannelPlus. It seems that unless the baseband video in is live when you select a channel on the unit it transmits a black screen. Resetting the channel after making sure the video in was live did the track. Quality is pretty good. I set up two monitors side-by-side, one displaying the hi-res video output directly and the other the modulated feed for comparison and you really can't tell the difference. We'll see how it looks once it runs out over the real cabling and distributions amps but the wiring is all pretty new good quality RG-6 so I'm hoping it stays clean.

 

Larry

[SureVeillance 0]

I wish you luck. In the past, I have tried similar modulators and everything looked great until I tried to combine the signal with the cable TV feed. At that point, the background 'noise' on the supposedly unused channel causes significant degredation making the signal unusable. Of course, to do it right, you need to run the incoming cable TV through a notch filter to drop out the channels you intend to add, but good luck finding a notch filter that drops out channels that aren't in use.

 

In the end, I usually end up distributing the video over cat 5 using a 4 to 1 balun. For example, from a GE DVMRe, I can send monitor A, B and 2 dedicated cameras over the 4 pairs, so for each TV I can choose what I want to view and most TVs have multiple AV inputs these days.

[rory 0]

Ive used Channel Vision in the past, you get the filters for channels such as 72-78, etc, and thats the ones you are filtering out. With regular cable TV there is no actual channels on those, but you still need to filter it or the video will be full of noise.

 

But direct into the AV on the TVs are always going to be best quality.

[SureVeillance 0]

Agreed for 'normal' cable. The thing to look out for is digital cable which may be using those channels for pay per view.

[scorpion 0]

Bright house in Florida is the same way. All of the channels are used even though you do not see video. The upper end of the 70 is used, as well as everything in the 80s, and the 90s.

 

There are some houses that use multiple set ups with analog only TVs, and other TVs in the house that use digital boxes, and other TVs that are high definition TV.

 

Regular cable feeds without boxes will have to be divide off, and then have the modulated signal injected in. You will have to take the seperate feed for the digital boxes, and inject the signal for this path. This will make balancing the cable feeds with the injected signals easier.

 

If you do it as a single circuit you will have camera pictures on the analog sets, but you may crash the digital boxes. If you balance it for the digital boxes you will be mismatch with the analog signal.

 

I have stopped modulating into cable, and now I have to educate the customer about source selection on their TVs. Now you will get those phone calls that the cameras have stopped working. Keep notes how they are up so that you can get them back up by reteaching them how to select the input that brings up the cameras.

[VJD 0]

Or you can try the Affinity Digital Modulation Kit and not have to eliminate any channels.