HDCVI Signal Problem

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So I'm stumped, did a 16CH install in a condominium complex last week, and three or four cameras are having a sort of signal issue, and it's weird. The longest run in 200FT on Siamese pure copper, and they are run all inside walls, no piping or anything like that.

 

My problem is this, it's 4 floors total, 2 cameras per floor, wires running same path to basement to DVR. Using a power box, 18ch, 20AMP, reputable brand. some of the cameras are showing this weird interference in the picture, at first I thought it might have been a length issue, but the other camera on that floor has no issues, so it doesn't make sense for this to happen. I attached a link to YOUTUBE so that you can see what I'm talking about. Before swaping cameras out, I need suggestions, and yes I already checked the connectors.

 

[SunnyKim 2]

Waving your hands or walking or running in front camera, you can tell "Frame Drop" which is caused by Loss of Video Sync Signal embedded into HD-CVI. Long Distance is mainly responsible for Losing Sync.

Noisy videos could be coming from bad connections or bad quality cables or power shortages. I can say that cheap brand cables do not run through rather strict tests. Too cheap to afford.

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I understand everything you have said. Im using good quality Belden cable, and like I said on camera on the same floor and using the same cable looks good and the other next to it gived me this problem.

[SunnyKim 2]

The same cable and on the same floor?

Completely power off the good ones and check whether the bad one can be improved. This is to check any cross interference when many cables are bundled together. You may also switch the camera input ports of the DVR to check the input impedance matching is correctly done on the input ports of the PCB board.

[c2lkis 0]

if you are using a video balun transceiver, try to replace it. Just for testing, go near those cameras and connect a power adapter using an extension cord and plug it to the nearest power outlet. Then See what happens?

[aibudo 0]

In case I missed something, is it possible that you could switch the camera's on the same floor and see if the "noise" stays with the same cable, or the noise stays with the "noisy" camera? 200' is nothing on good Siamese RG59/18-2 cable. I have camera's running 400' outside in the weather with no issues like that. It's hard for me to think that you have a power issue with a 20 Amp Power Supply, especially when some of the camera's are working just fine. I have had an issue once, where the camera's were metal cased and the mounting screws went into metal studs, instead of wood or drywall and that caused a "noisy issue". I also have viewed camera comparison's of SDI, CVI, TVI and AHD (side by side) and wasn't happy with the SDI or CVI. I know that there are different results with different camera's, but the example that I saw was the case. In your case, if the camera's are all the same, then more than likely you have another issue.

 

Dennis

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all the cameras are the same, dahua's HAC-HDW1100M, and I am going back to the site tomorrow and I will switch some of the cameras out and see of that's the problem. The cameras are mounted on drywall with plastic anchors, and the wires are on the same path to the DVR, but here's the thing I didn't quite explain, the building has a left wing and a right wing, with a foyer and elevator in the middle. Do I have 4 runs on the left side of the building coming down to the middle, and 4 on the right. Right side has 2 cameras acting up, and the left side has one acting up.

 

What I'm getting at is that two different runs developing the same problem is odd. Any ideas keep them coming, thanks for the help.

[aibudo 0]

I'm real curious to know what you find out by switching camera's.

[tehnet 0]

What is the diameter of the supply cable? do you have a camera with 12V? This is a first.

I think you have some interference from AC power.

Have you tried also to replace a position of the camera?

And also check that you are a good fit BNC connectors on DVRu

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So I finally had a chance to go back to the site with some time on my hands and figured out the problem. There was a bad ballast on a light fixture that was close to one of the lines and it caused interference on some of the channels. After resolving this, the image got 90% better, but I still had small lines going across the screen. The fix is a weird one, after playing with different settings I changed the cable type from Coax (which I'm using) to UTP on the dvr's menu, under the camera settings and the images came in clear as day.

 

Hopefully this can help others with this similar issue.

[emadezzo 0]

Thank you for your experience.