Bought four 12 volt DC powered ir cameras with built in illuminators. Also purchased an additional fused 8 output terroidal transformered power supply. Getting lines in the same two cameras scanning from top to bottom. At times the interference is worse, so much so that the actual picture will jump over to the other position that shares the interference. Upon further inspection of the install the installer had a run a 100 foot extension cord for the Dvr and plugged it into a powerstrip shared by the two power supplies. When I plugged the one power supply into a plug not in the power strip but presumably different circuit across the room the problem seemed to dissapear...initially. It then returned later and is random in it's behavior sometimes almost invisible and sometimes terribly jumpy.
I also used what I now term the gumpack ac to dc converters available for around 6 bucks a piece. One for the camera and one for a receiver/driver at the same location. The pan and tilt platform is 24v ac. These devises are only putting out 9 volts at best. When the platform is activated it disturbs the video probably due to the voltage drop from an already weak 9 volts.
When this one camera is disconnected the video interference on the other one stops. Where can I start with diagnosing this problem? Why would this one camera effect another and always the same camera but not the other two?