Interference using cat5 on analog systems

[Chattels 0]

Hello all,

 

OK so here is the problem i am having. My company works in the hospitality industry, installing phone systems, high speed internet, CCTV, and audio systems for hotels. So we started the CCTV thing about 3 years ago, and as you all know every install is different. Well the ongoing problem is that the electricians are pulling cat wire in, and we are having to use that for the time being. I would like to use RG59 Siamese cable because it is very rare for it to pick up any interference. Anyway we get the cams up and come to find out they pulled it in next to a fire panel, or across some 220 live wire ext. The end result is horrible scrolling, color distortion, ghosting, and graininess. As of now we are under the gun for this job. Is there some kind of filter or anything i can do to fix this problem ASAP? All the cable runs are stapled to the framework behind the drywall and moving anything isn't an option for this property. Any thoughts, ideas, suggestions, I am totally stumped. Thank you all in advance and all help is appreciated.

[VST_Man 1]

I'd try a BNC ground loop isolator on the DVR side.

[the toss 0]

Either educate the electricians or get ones that will do what you ask.

[VST_Man 1]

that was actually funny

[gb5102 0]

Sounds like ground loop(s) causing interference to be picked up/amplified

 

Guessing you are using 12vdc cams, and the power 'ground' wire is tied to the video 'ground' wire? (can verify with a multimeter...)

 

If so, use 24vac or dual-voltage cams as these typically have isolated 'grounds' due to the layout of the power circuitry(even if you still run them on 12vdc)

[Samir 0]

You could convert the analog signal to digital and run it digitally over the cat5.

[the toss 0]

Sounds like ground loop(s) causing interference to be picked up/amplified

 

Guessing you are using 12vdc cams, and the power 'ground' wire is tied to the video 'ground' wire? (can verify with a multimeter...)

 

If so, use 24vac or dual-voltage cams as these typically have isolated 'grounds' due to the layout of the power circuitry(even if you still run them on 12vdc)

 

 

That is not correct. It is the power supply you use that determines the ground isolation since that is where it occurs.

[joseph.chen0312 0]

For avoid interference you better take cat5 or coaxial cable w/STP

[jazzar 0]

Am I picking you up right that you are not currently using rg59 cable- that you are using the cat5 cable for the video signal- If so:-

its a bad idea just to stick a bnc connector straight onto a twisted pair cable at both ends.

if you are using the cat 5 for the video transmission you need to have a bnc to twisted pair convertor at each end of the cat 5 cable that you are using- or media convertors to convert from bnc onto ip and back again to bnc using the cat 5 to send the ip signal.

Also cat 5 should not be stapled - the staples can crush the wires and increase signal degradation.

Addlestone electronics do a lot of Video signal correction kit across twisted pair- you could check out their web page.

and google video media convertor- plenty to choose from.