CCTV camera

[mattyh]

I've got a new build house which is wired ready for a CCTV camera... i have a spare RF lead in the loft ready to connect to the distribution amp, and next to the front door I have a wire concealed behind a blanking plate. When I removed the blanking plate and touched the wire I got a bit of a shock from it, so I'm assuming both power and signal are combined within the one RF lead (though it doesn't have a connector on the end at the moment)

Does anyone know what kind of CCTV camera i'd need to buy that would work here? Looking around it seems they all require seperate power suppies!

Thanks in advance!

[Peter Johnson]

Ask Bill Wright in uk.rec.digital-tv

[Peter Johnson]

or even uk.tech.digital-tv

[Lurch]

On Wed, 15 Aug 2007 06:02:45 -0700, mattyh mused:

I think that somewhere you are mistaken.

Any chance of finding someone who does know what you actually have? I would be surprised if a cable had been put in, phantom powerd and modulated ready for plugging striaght into a distribution system, but no camera fitted. The camera would have been the cheapest part of the job.

Are you sure you got a belt, and not just a static discharge? I'd imagine the cable would be a bit of co-ax stuck in the wall from the box to the loft, and that's it.

[Dave Plowman (News)]

Please don't. That group has got nothing to do with CCTV. There are other more suitable ones. And Bill is an expert on aerial erection and distribution - not CCTV.

[mattyh]

Thanks for the responses, and apologies if i'm in the wrong group, it's difficult to know where to post!

I do think it's powered... in a Homer Simpson-esque way i put my finger on the wire several times and got a buzz each time before working out that their may be power there. The other thing that makes me suspect this is that other homes on the development (that opted for the camera install) appear to only have one wire going to their cameras.

The charge for the fully fitted camera from the home builder was about =A3200 hence the reason I decided against it and am now looking to see if I just need to buy a cheapo camera!

[Harry Bloomfield]

on 15/08/2007, mattyh supposed :

The shock seems likely to have been the small amount of leakage which is normal from a TV to its antenna. The outer screen is not normally taken to an actual ground, the distribution amp will also be lacking a ground so will pass the voltage to the wire you touched.

It does seem a little odd that such a cable has been installed at all, without a camera. If such a thing exists - you will need a camera with built in RF modulator, possibly able to be line powered. The RF modulator changes the cameras A/V type signal into the equivalent of a TV channel receivable by a normal analogue TV.

A camera with the more usual A/V signal output can be plugged straight into a SCART socket on your TV. We have one plugged into the SCART and it automatically switches the TV to the cameras view when ever the camera 'sees' some movement in its field of view.

[Lurch]

On Wed, 15 Aug 2007 20:34:18 -0000, mattyh mused:

Thinking and knowing are 2 entirely different things.

You need to find out what the cable is, where it goes and whether there is any other equipment connected to it. I suspect not.

£200 isn't far off the mark for a half decent camera properly fitted and fed into the distribution system.

[mattyh]

You're right, thinking and knowing are two seperate things, and without contacting the builder I can't be sure.

However, the reason I thought there was power there is because I found what I suspected was the other end of the wire in the loft not plugged into the distribution amp. If it's not plugged into anything that end then I don't see how any static or anything could get down the wire, so could that mean that power is provided onto it somewhere else down the line?

Thanks again for all your help, though I suspect I may have to pose the question to the builders to find out what's connected to what!

[Frank Erskine]

Some cameras are phantom power fed. What you'll have to do though is to measure the voltage coming back to the camera to check that it's 'real' power and that the voltage is suitable for your camera. If you have a conventionally powered camera, you can build (or buy) a power separation filter, which splits the dc (from the cable) from the video (the camera's output), if the dc is suitable...

[Lurch]

On Thu, 16 Aug 2007 10:44:52 +0100, Frank Erskine mused:

I'd forget about phantom power feeds for now.