elderhome

I dunno how to canel the vertical bar on each quad screen, it runs (looping) fr left to right or fr right to left. Please advice. My config is 4 dome cameras in the same floor and the total cable running is not over 80 feets, connect to DVR then to TV. Two of camers is sharing one 1.2A power supply, other twos are using indvidual 0.5A power supply. How to solve this problem, plz help!

Hi rory, Thank you for ur advice. I tried the RG6U (double shielding) cable already, still have the vertical bar running. So it is not the EMI issue casued by flourscent light or high voltage cable. When I replace the DVR by the quad machine, everything is fine , no any vertical bar running now. So i take the DVR to another site to test with four cameras, and the result is no any vertical bar running too. It is very strange. Therefore I dunno the problem is caused by DVR or cameras or transformer or other issues, let me very confuse now! After that, I installed a 25V 2200(uf) capciator at each of 12V supply line, but still got the vertical bar problem. I also disconnected all the "ground" from sockets ,but still got the vertical bar problem. Tomrorow I will tried each camera use one 12V power supplyindividualy to see the result. If you have any advice, pleaes let me know.....Thank you!

HI VST_Man, I did installed the ground loop transformer to each camera and DVR or one by one, and not work. But I dunno it should be a ground loop problem or not. I noticed that If I use one camera is fine, no vertical bar occur. If use two cameras vertical bar appear in both screen. If use three cameras, more vertical bar appear.......It means more camers, more vertical bar. And all the stuffs are connected to a same AC power. So I dun think it is a common ground problem....I really no idea now........I need help and advice. Thank you!.........

Hi Securitymaster, Thank you for ur advice. Now I see, two of the quad screens having two visible vertical bar running on each screen, one is faster and another one is slower, fr right to left, very strange. The other twos having only one visible vertical bar running fr left to right. Why the vertical bar is running fr left to right or right to left, and not in the same direction? Why there is two vertical bars in one of the quad screen? I really get into trouble now! Please advice. I using RG59 cable and each cable is running not over 20 feets. You're right there is many flourecent light, but the distance between the light to cable is 3 feets away. I think you mean the electric magnetic interference, right? So I take ur advice and I will try to use a RG6U (double shielding cable) to see the result today. Thanks