generatorlabs 0 Posted January 5, 2015 Hi: I am attempting to wire up a multi camera DVR over Cat 6 Cable. If I power a single camera up the image is great. If I connect any 2nd, 3rd or 4th camera they all have noise (bad ghosting that scrolls right or left) All cameras have their own terminals in the power supply but share a common bus in the wall mount supply. With the information I have found here I have purchased and am using the following: 8 Channel DVR 4 Outdoor cameras I have an 8 channel wall mounted power source. I have tried the wall wart transformers that came with the cameras and I get the same result. The cable runs are 200-300 feet. I am using pure copper Cat 6 cable. Each camera has it own dedicated Cat 6 pull. I am using the blue pair for video with baluns on each end. I am using the remaining pairs for power, tying the solid conductors together and the striped conductors together. I have also tried an active UTP transceiver on the DVR end and passive baluns at the camera. Problem still there. The only other thing I could possibly think of is DC-DC isolation converters at each camera. Please help....I am at the end of my rope Share this post Link to post Share on other sites
Numb-nuts 1 Posted January 5, 2015 Why did you use Cat6 and not cat5 ? Good way of using a single cable for both power and video but how have you terminated the DC pairs? The problem sounds like a power supply issue. Remove the power from one camera at a time and see if one of them is the culprit because it sounds like one or more of the power lines is introducing a ground loop I use the identical wiring convention to you, and never suffer the same issue. Measure the voltage at each camera from the DC supply cable and it should be within the range of around 12V + or _ 10% Share this post Link to post Share on other sites
tomcctv 187 Posted January 5, 2015 Hi. You will need to list your power supply spec Also camera spec also type of balun Amps is going to be your problem over nearly 100m Share this post Link to post Share on other sites
generatorlabs 0 Posted January 6, 2015 Why did you use Cat6 and not cat5 ? Good way of using a single cable for both power and video but how have you terminated the DC pairs? The problem sounds like a power supply issue. Remove the power from one camera at a time and see if one of them is the culprit because it sounds like one or more of the power lines is introducing a ground loop I use the identical wiring convention to you, and never suffer the same issue. Measure the voltage at each camera from the DC supply cable and it should be within the range of around 12V + or _ 10% I used Cat 6 because it was a heavier guage, and was solid copper. I was weary of using cheaper Cat5 with copper clad wiring in this application because of the distances involved. But in reality the distances are not long at all. 200 to 300 feet on UTP should would fine. I am not pushing the envelope or at least that is what I thought. The DC pairs are connected to a quick barrel adapter on the camera end and are connected to screw terminals inside the power supply on the other end, near the DVR. 3 Solid color conductors for NEG and 3 striped color conductors for POS. Initially i thought the wall mount power supply was the culprit but the exact same thing happened with another supply. The cameras came with a wall wart power supply with a four way splitter however I thought the voltage drop across the cable would be a little much for a tiny wallwart supply. The wall wart power supply seems to power the cameras just fine but even it produces noise if more than one camera is connected. The large power supply is adjustable, so I thought I would just raise the voltage one or two volts to compensate for voltage drop. Made no difference. So I set it back to 12.2 VDC. It was getting kind of late so I walked away from it. I will give it another go tomorrow. After some reflection I think I will try a high quality NVT balun on two of these cameras and try it out then. Maybe the cheap baluns I bought on EBay are the culprit. I am still open to any suggestions though. You folks may have seen something I havent observed. Thanks! Share this post Link to post Share on other sites
generatorlabs 0 Posted January 6, 2015 Hi. You will need to list your power supply spec Also camera spec also type of balun Amps is going to be your problem over nearly 100m This is the specs listed for my supply Model: MLT-18CH-NF with cable 18 Port CCTV Camera Power Box 18 Individual PTC Protected Terminals Input AC 110-240V Output: 12V DC, 12A Terminal Connection Max Draw: 20 A Support up to 18 Cameras On/Off Switch Key Protection The cameras are low current Lorex outdoor units with metal housings, but I am using them indoors. I do not believe that each camera will consume more than 275 ma with IR on. I don't have a spec sheet in front of me but I can look up the exact spec tomorrow when I get back to my desk. The baluns are cheapo units I bought on Ebay. After some thought I am thinking that they may not be true isolation type transformers but I dont have enough experience to really be sure. I guess I could try to test that theory with an ohm meter tomorrow. I have some better NVT baluns that I am going to test on two cameras tomorrow. The active transceiver I am using at the DVR is a multi channel Pelco unit. I have taken that unit offline though until I can pinpoint the problem a little better. What do you think? Thanks! Share this post Link to post Share on other sites
Numb-nuts 1 Posted January 6, 2015 (edited) mmmmm, sound like MR Know it all needs to make a comment here........ Edited January 6, 2015 by Guest Share this post Link to post Share on other sites
tomcctv 187 Posted January 6, 2015 Forgive me for stating the obvious for the uninitiated, but it's the volts at the camera that counts What you start out with is not really important. I see your approach but if I had no choice, I would run 24VAC and drop it down to 12v DC regulated at the camera end, in such a circumstance. You could break the earth past by introducing a anti hum device but as a last resort. I can understand why a DIYer would think that. can have 10 or 12 even 13v at camera but it still needs amps ........you can under amp a camera you cant over amp it and if you look at ops power spec 1.2amp each. at power supply ....... sorry but op is not going to get 1.2 amp at end of 300ft and adding anti hum on cat6 with baluns ........... that has to be a joke ???? it must be. generatorlabs. it is best buying good quality baluns lots on ebay stating are baluns but are not also cat6 is always best away from other power cables ..... never run across other cables. 0.275ma is low for a camera with ir can you list spec of cameras Share this post Link to post Share on other sites
tomcctv 187 Posted January 6, 2015 mmmmm, sound like MR Know it all needs to make a comment here........ No not a comment it's fact. You need your editing rights taken away from you .... So others can understand the crap you type No point you giving crap then removing your crap You give advice use humbugs with cat6 and baluns I like to think I have just saved the op $30 a camera with putting you right with your bad advice Share this post Link to post Share on other sites
generatorlabs 0 Posted January 6, 2015 OK guys I feel like I am in the middle of some crossfire here and now I stand a little confused. Anyway per request I am putting up the specs to the cameras in question. They are all identical. Power Requirement 12V DC ±10% Power Consumption Max. 350mA (w / IR) Image Sensor: 1/3” 960H CCD Video Format: NTSC Effective Pixels H: 976 V: 494 Resolution 700 TV Lines Scan System 2:1 Interlace Sync System: Internal S / N Ratio: 48dB (AGC Off) Iris: AES AES Shutter Speed: 1/60 ~ 1/120,000 sec. Min. Illumination 0.1 Lux without IR LED 0 Lux with IR LED Video Output: Composite 1.0Vpp @ 75ohm Share this post Link to post Share on other sites
generatorlabs 0 Posted January 6, 2015 I had a three NVT NV-214-M baluns that I had sitting in my assorted cables drawer and connected them to the system. There is a 100% improvement with these baluns as opposed to using the cheapo ebay units I had. I am using one NVT balun on the camera end and terminating the other end to the Pelco active transceiver. I only had three of these baluns so I am going to have to order another thirteen to complete the project. I have to find a source to get these at a great price. Open to suggestions. Thanks for the help. Share this post Link to post Share on other sites
generatorlabs 0 Posted January 7, 2015 Since my problem has been resolved with the NVT baluns on my first 3 channels, I decided to see if I could get some more on Amazon. Wow these things are pricey for a passive device! Can anyone recommend a rock solid balun that will perform like the NV-215A-M, with a better price? And a reliable source? Thanks for the help! Share this post Link to post Share on other sites
Numb-nuts 1 Posted January 7, 2015 A generic Chinese brand is Folksafe , I have found these are very good, available in the UK under the brand name Balun King from CCTV Direct These are all more expensive but IMHO worth every extra penny. There's also Muxlabs offering but they ARE expensive and I only use those with top of the range equipment where the equipment value is higher and warrants it. You wouldn't put retread tyres on a Rolls or Mercedes would you? Sorry about the crossfire, just do what I do ignore the snipes or petty comments. Its a shame because he often has some very valid things to say. Share this post Link to post Share on other sites
