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erraville

Intereference on Video

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Hi, can anyone please help me what to do with my cctv with 2 channels showing waves like there is water inside but there isn't and also, the image has stripes like that of jeans pants? but when i use camera tester, the camera has a very clear image... and also, when i insert other cameras on channel 1, it is also clear... probably the cable but i used same cable on all cameras and some are longer than this with no problems...

 

although the location of the camera

 

hope someone can help...

Pic_20110819092819_1011_1.jpg.6ed25e390ee60fcb58829ea5efe545cf.jpg

Pic_20110819092829_1011_2.jpg.1f01d5682607cd68ea4f792af3610387.jpg

P8121549s.jpg.c88ed02c0b32c23253949ed427419143.jpg

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Hi, thank you for the quick reply... is there a balun or something that can be put to avoid interference? or transferring is the only solution?

 

thank you very much

 

errol

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What type of cable is being used, distance, and power?

 

May be more to it then just interference from the high voltage.

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RG6U w/ Messenger, 60% braiding cable used, around 80 meters and using 10A central power supply with individual fuse of 1A per camera.

 

also, as you can see on the picture, the electricity power lines are on the left post and the camera on the right post and they never came near each other.... about 5m apart... also, it's a private power transformer and only supplies power inside the compound and no other residences...

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Thats the wrong wire, thats for TV signal.

I knew Ive seen that type of issue before .. from an old job I did with RG6U.

Ive also seen it when I tried running one of my own cameras 50' with Telco wire and no baluns.

 

Cant guarantee you still wont have a problem, but thats not uncommon with using that cable for CCTV.

Might not even be that high voltage causing the problem. But just to check it first, perhaps take the wire down at least to the ground far away from that area and test it there, if its the same problem then its somewhere else on the line, either way I would change the cable for RG59 Copper solid center and 95% copper braid..

 

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Ok Sir Rory, will try to do that... also, is an RG6 w/ 90% braiding not also enough? I'm just not sure I can find rg59 here w/ 95% braiding... but the rg6 w/ 90% i have in stock...

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As long as its copper and not aluminum yeah it should work.

 

Dont quote me on it though as I havent used that same cable.

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Aluminium braid -

 

But first - plug the power pack into an extension lead - then if your country has three pronged plugs.. IE one plug is ground, cut that ground off....... actually no DONT do that... but that would be a way to see if the ground was affecting it... could be different ground potential

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RG6 is not needed for the application and will work as long as it is the standard 75 ohm type with copper center conductor, aluminum will be fine for the braid. Tear apart almost any of the elcheapo premade BNC cables and you will find that the center conductor is copper with straight ran thin aluminum wires or wrap around it, not even a true braided cable at all. Of course everything depends on run length as well and copper braiding has lower resistance and works better on longer runs. I doubt 90% braid will be different in this case because of the close proximity of the transformers. Many of the cheaper CCTV cameras out there have less shielding on the circuitry than the cabling provides. The camera circuitry itself can pick up interference from the transformers. I have seen interference from common old flourescent lights with cheap cameras close to them (picture waves). The only thing done was changing the cheap camera out for a better one and the problem was rectified. Only in Iraq have I seen CCTV on transformer mounts. lol Best suggestion is use the existing cameras and cabling in a different mount location and see if that solves your problem. If not, go for RG59 with copper center conductor and shielding. You will find it there in the Phillipines easily enough, it is common and not very expensive either.

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Hi erraville.

Which two cameras are having problems? Only the two circled ones in your photo?

My guess is that you're getting interference from the wires in the white pipe. Over what distance do the orange (camera) and white pipes run together?

Where do the wires in the white pipe go? They appear to be three phase plus neutral.

The diagonal lines could be from a switch-mode power supply. Do the three phase transformers supply a factory with a large motor connected to a variable speed drive? Or other big power supplies?

You could try to use twisted pair instead of the coax. With a balun at each end, it might be able to suppress the common-mode interference from the wires in the white pipe, but I'm not sure.

Coax with a 90% braid might do the trick as well.

 

Your best bet would be to move the cameras away from the transformers, and keep their wiring away from other power wires.

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