Im having problems with one of my customers cameras, he has 8 in total. 5x killercams, and 3x covert pir cams, the killercams work perfect but the 3 coverts are getting really bad interfearance, from what looks like the dvr (adata collossus pro) i have rewired, bought a ground loop isolator, installed a bigger regulated psu, the problem is no better. also tried each camera separate to rule the other cams out. the only thing that improves picture is shutting the dvr down for 5 mins and then powering up, it gradually declines from there.
before this job i was only familliar with cameras that take a hard wired 12v and have a bnc output. these 3 coverts are wired in cat 5. the terminals inside camera are +12v GND VID. they were wired so the VID ends up to the central bit of a bnc connecter via terminal strip to coax and the outer sheath of the bnc shares the psus ground. the cameras work the same if i disconnect the psu ground and just have the 12v connected but so far nothings improved picture.
i will add these worked perfectly for him for 2 years wired up this way.
any help would be really appreciated.