distortion at night

[Qualitech]

i installed a lorex analog 4k camera system for my buddy at his mom house. i used cat-5 with video baluns with a 5 amp power supply. one camera in the backyard comes up with wave lines at night intermittently then clear up. in the daytime it’s fine. At my house i have analog dome cameras as well that i got from a camera supply house same thing happens on the front camera but but it’s wavelines all night and soon as dawn hits it stops any advice on what causes this type of distortion on analog cameras ( btw i am using the same type of cabling cat-5 over baluns and a 5am supply and the footage is under 328ft)

At my friends house there is a store next door that have a illumated sign that comes on at night maybe EMI is being transmitted from that not sure but there’s nothing like that at my house?????

 

[wittaj]

It sounds like the cables may be crossing over electric wires.

Do the cameras kick into B/W at night? That would be more noticeable then. Or when it kicks into B/W, the power supply isn't enough to power the IR.

 

[Qualitech]

it kicks into b/w and that’s when the waves begin one property is on and off for about 10 minute intervals and my house is all night no electric in the backyard

 

[bigredfish]

That can be hard to track down. I’ve experienced a number of times with my Dahua CVI cams.

Things to check

• induced 60 hz power anywhere in the line as @wittaj mentioned. Could be right at the dvr
• bad balun. Easy to replace
• certain exposure and gain setting combinations especially if an LED light is in the FOV
• bad cable (ants and other critters) or corroded 12v power connection
• lastly, try a separate power source for that camera. Sometimes on shared power sources you get weird power problems like that. Use an extension cord and run it on its own wall wart to a separate 120 volt outlet.

 

[sebastiantombs]

^^^ All of which add up to good reasons to avoid CVI whenever possible. Back in the day when I was installing CVI all the cable was in metallic conduit, properly bonded, from the camera to the VMS. Never had a problem with induced EMI causing video problems.

 

[Qualitech]

g

That can be hard to track down. I’ve experienced a number of times with my Dahua CVI cams.

Things to check

• induced 60 hz power anywhere in the line as @wittaj mentioned. Could be right at the dvr
• bad balun. Easy to replace
• certain exposure and gain setting combinations especially if an LED light is in the FOV
• bad cable (ants and other critters) or corroded 12v power connection
• lastly, try a separate power source for that camera. Sometimes on shared power sources you get weird power problems like that. Use an extension cord and run it on its own wall wart to a separate 120 volt outlet.

got it i will definately try all chances of a actual bad camera being in that mix?

 

[Qualitech]

^^^ All of which add up to good reasons to avoid CVI whenever possible. Back in the day when I was installing CVI all the cable was in metallic conduit, properly bonded, from the camera to the VMS. Never had a problem with induced EMI causing video problems.

it’s actually a tvi not sure if that makes a big difference but what do you suggest for best wiring siamese cat5 or cat6 which offers the better sheild to prevent these things.

 

[Qualitech]

That can be hard to track down. I’ve experienced a number of times with my Dahua CVI cams.

Things to check

• induced 60 hz power anywhere in the line as @wittaj mentioned. Could be right at the dvr
• bad balun. Easy to replace
• certain exposure and gain setting combinations especially if an LED light is in the FOV
• bad cable (ants and other critters) or corroded 12v power connection
• lastly, try a separate power source for that camera. Sometimes on shared power sources you get weird power problems like that. Use an extension cord and run it on its own wall wart to a separate 120 volt outlet.

also what if i double up on the pairs going to the power supply maybe doubling the power will help the night IR

 

[sebastiantombs]

I don't use Siamese cable at all. My system is IP using PoE, no secondary cable to power the cameras that way and never had a problem with induced interference simply by keeping the CAT cables away from power cables by a few feet other than if they have to cross one another. When they cross, they cross at right angles. Back in the good old days, it was Siamese cable but again, always in bonded metallic conduit, and this was in industrial applications with lots of high horsepower, three phase, motors starting and stopping all the time.

 

[bigredfish]

I use Cat5 for my Dahua CVI cams. (TVI is almost identical, it’s HiKs implementation of HD analog) but also have Cat6 direct bury at Moms house.

I use 3 pair for power and 1 pair for video.

Most every time I’ve had the rolling lines it was from the power supply or interference close by the DVR where everything comes together, but always on the power side.