Hello everybody,

I'm having some problems with my camera, theres some kind of interference or distortion present in the image and I have no idea what it could be, but it looks like a wave each 43 pixels vertically.

I have attached a screenshot...

Did anyone have this problem ever ? Could anyone help me ?

Thanks in advance.

Regards,

C.

From what i can see your pointing this a the train tracks right?

Yes, it is pointing at a train track.
Maybe electrical intereferences ?
Do you have a guess ?

Thanks.

Looks like a 60 cycle hum.

I'm using passive transcievers to transmit the signal like 40 meters, what would be the way to avoid this hum ?

Is this a one channel problem, or a multi channel problem?

As a quick tech check, discontect the camera from the mount and make sure it is isolated with card board or something, then check the video.

If it is clear then it is a ground loop issue.

If it is a 60 cycle hum as RickA pointed out then that would be a power supply problem. You will have to switch out the power suppy to check that.

It is possible that a camera is injecting the 60 cycle in to the power supply "system", and you may want to disconnect all of the cams except one, and then check the video to see if it is clear. If it is clear then you can assume a camera is the cause, (or a wire), and you can rehook each camera one at a time until you find the source.

Do you have a hand held monitor to see if you have clear video at the end of the line opposite of the camera?

I do not know if you are using a DVR or what as it might be a DVR problem as well. I have seen issues where the wall plug is at fault causing erractic behavior in DVRs. I should know after swapping out two DVRs until I figured the wall socket was miswired by a bar owner!

Hope you find it!

Thanks a lot,
Now I have some guidelines to check the problem, you've been of great help.

Regards,

C.

Yeah, if the camera's BNC shield and power "gnd" are connected together at the camera, and then your power supply (-) and DVR chassis are also connected together 40m away then the benefits of a balanced twisted pair may be not be fully realized.

I guess that means use a single isolated power source per camera.

could be on the supply but that looks like its induced,
Running Coax will fix that also.

My thought is that the high voltage from the overhead power lines are causing this problem how far is the camera from the train tracks or the overhead power lines.

I am guessing here but 50/60 cycle hum. Is this in europe?

i have attached a sample pic, could I have the same "cycle hum" problem as mentioned above? If so, how is it fixed.

Not sure if this is necessary, but i am in Canada, but my cameras came form Hong Kong.