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 Post subject: Diagonal pattern on CCTV camera
PostPosted: Tue Mar 14, 2017 1:37 pm 
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Hello,

I've done as much research as I can without reaching out for help. Hopefully someone can guide me toward fixing this. All of the cameras on one of my DVRs have diagonal lines running through them when viewed live or on video. I chose one specifically to try to tackle first, and here is what I did to combat the problem to no avail:

1) Replaced camera
2) Re-ran very long RG59/U cable (through an attic, and down a 3floor plastic conduit, under the ground, etc) with 95% braid ALL Copper, no steel in either the braid or the core
3) Turned off all other cameras temporarily to see if it was our power distribution block
4) Unplugged powered antennae
5) Camera is mounted on metal. Held camera away from mounting point to avoid grounding issues.

Before running the cable through the attic and down the three floor sheer wall, I ran the RG59 down the stairs and around the building. NO diagonal pattern was witnessed on this camera in this condition. However, the other cameras still had this pattern during this time. The pattern re-appeared when running through proper channels.

See attached picture for current state. Note: this is a license plate camera so B&W is expected

None of these helped. Our setup has 9 cameras on one DVR. All are powered through siamese cable. 8 through a 24v power distribution block and the brand new one through its own 12v power brick.

I've wasted a TON of time and sleeplessness trying to solve this. Anyone have an idea?

Thanks,
Steve


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 Post subject: Re: Diagonal pattern on CCTV camera
PostPosted: Thu Mar 16, 2017 1:50 pm 
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Just tried adding a ferrite core to the DVR side and one to the camera side. No change at all.

Any help would be appreciated,,,


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 Post subject: Re: Diagonal pattern on CCTV camera
PostPosted: Thu Apr 20, 2017 3:48 pm 
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By the number of lines of interference it looks like either RF or Switching power supply interference. Does this system have a UPS uninterruptable power supply in use, or is there one operating near by on the same power mains as the camera with this problem? If so try turning it off and disconnecting it from the power mains. If not is the camera grounded by a DC power supply on the negative side or the BNC cable side? Disconnect the camera from its mount and hang the camera from its cables to find out. Do the lines stay in one place but dance around, that would be a classic UPS interference signature. Or do you live across the street from a high power Radio tower? If this interfering signal exists on your power mains then you can try isolating the power supply, if 12 volts use a battery to test for ground loop by powering the camera from a battery. If hanging the camera from its cables works then mount the camera on an insulator to lift the ground. A UPS interference is usually the cause of this type of multiple lines on the screen. If it is a UPS then try to find a simi-sign wave type of UPS instead of the cheap square-wave type so commonly used.


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 Post subject: Re: Diagonal pattern on CCTV camera
PostPosted: Mon May 01, 2017 3:04 pm 
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Had the same type of interference, driving me nuts as it was registered as "motion". Working with an inexpensive unbranded Chinese 1080P H264.DVR and a similar AHD-H camera, I learned that I had to use another power supply (not to work any longer with a splitter and a joined adapter). Even more more important was plugging in an audio in cable.


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 Post subject: Re: Diagonal pattern on CCTV camera
PostPosted: Mon May 22, 2017 10:17 am 
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Could be a ground loop.


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