12vdc Through Coax (Pre-existing setup)

[lukey_088]

Hello there,

Just a quick question regarding a simple upgrade on a pre-existing surveillance setup we have in a particular area. A few things I should let you in on here, this work place expects security yet there is no real budget for it, if it were up to me everything would be torn out and done again.

The old system consist of 4 cameras, a Panasonic video recorder and a Panasonic monitor. The power for these cameras are powered by 12vdc which is supplied from the monitor via coax with BNC ends.

As I have not been given any other resource but enough money for a simple DVR (to save time on tape changes) I can not run any cable for the 12volt the cameras need, plus I do not want these on a multiplexer anymore, thus eliminating the old monitor and the 12volt supply from it.

Is there anything that anyone knows of that can send voltage down the coax but still have the output from the camera I can put into the DVR.
preferably 4 channel.

Once again i know this is a very poor way to do things (Maybe i've spent enough elsewhere ;-D) but its all i've got to work with.

Cheers,
Luke

[iStorm]

No you cant sorry, What you need is RG59+2 cable, that will carry your video signal and power! hope this helps

[zodiac]

a possible alternative (hard to say though) is to connect to local power sources (if there are any) so that you can power the camera's locally and then you just have to transmit the signal back throught the co-ax

[Rhino]

New to ths game but the RG59 + 2 is a quality option but where and how do you terminate the twin power to the camera and to what power source.

[iStorm]

A psu sited by the monitor would not be an option? I know the op said he didn't want to run anymore cables but he wont have any choice unless he can find a power source next to the camera's as Zodiac posted, the only problem then is that you will need a power source for each camera meaning 4 psu's!!

1 Option run rg59+2 from the monitor to the camera's ( 1 psu + Drum of Rg59 )

2 4 Psu's sited by each camera

[thecctvguru]

You can send power up the coax, the devices are called Video Line Drivers.

Basically they send the power up the coax, and then take it out at the other end, giving you a 12v supply. (with the video sent back using an RF signal).

We sell them for about 105 a pop...

[ScottJamesConsult]

As the intstallation is so old are you sure the cameras are 12v they may well be 240v units powered from a local spur, if as you say the existing coax is RG59 then there would have been no provision to power down the coax and shotgun cable was not around either.

The only other thing I can think of is that the system is an old "observation type kit" that would have used special "plug and play" connections, again if this is the case strip back the cable and you should be able to expose the multi cores to connect to a new 12v PSU.

[Henry]

Was there ever an answer to this one ?

It seems a bit of a mystery as to how the old cameras were powered up ,(I'm going for the powered locally and video feed run back to the VCR guess ).

We may never know............

I would have thought when existing coax cables are in place it wouldn't have been the end of the world to use them as draw wires for a bit of RG59 +2 shotgun.


Henry