bentech 1 Posted January 26, 2015 Hi , I have 8 analog Cams connected to 12 VDC (power dist panel) and using RG59 (~600 feet with a union/junction). Image is poor , lines at the bottom of the screen , etc... What can be the cause of this ? -Should I use 24VAC ? -Ground problem ? -Need to boost signal ? -Termination at DVR ? Please help ... I have access to an oscilloscope. Thanks. Share this post Link to post Share on other sites
abdelm01 0 Posted January 26, 2015 Have you tried to view the cameras on a different monitor. First thing i would do is check the terminations on both ends of the lines. Share this post Link to post Share on other sites
bentech 1 Posted January 26, 2015 I have a video CCTV tester ST-895 , seem's to be OK on this. Any idea ? Share this post Link to post Share on other sites
Numb-nuts 1 Posted January 27, 2015 Check both connectors on your VGA cable for a bent pin, try replacing the VGA cable or the video cable Share this post Link to post Share on other sites
bentech 1 Posted January 27, 2015 Just to give you more info , I have 32 cams connected to the DVR. I have problems only with 6-7 cams that are in an other building. Can it be a parasite signal that goes on the 12VDC line ? My next step was to connect a signal generator at the place of one cam and see the output at the DVR side with a oscilloscope. I don't know if I connect them with 24VAC it it will be better. Is a Loop Isolation Transformer - GIT100 would help ? Share this post Link to post Share on other sites
walliams 0 Posted January 27, 2015 Have you tried plugging the cameras in individually ? Try plugging them in one by one as it may be just the one camera pulling the others down . Share this post Link to post Share on other sites
bentech 1 Posted January 27, 2015 Yes I did that. Samething. Share this post Link to post Share on other sites
Don Stephens 0 Posted January 27, 2015 How long are the cable runs to those cameras? What kind of cable? Share this post Link to post Share on other sites
tomcctv 190 Posted January 27, 2015 Hi. Can you give more info on how you have connected ....... Is power local to your 8 cameras ? Also just for a quick test do you have option on cameras to go black and white Share this post Link to post Share on other sites
bentech 1 Posted January 28, 2015 The 8 cams on that building have a 12VDC power distribution alone just for them. I changed it and samething. Now way for black and white Share this post Link to post Share on other sites
bentech 1 Posted April 1, 2015 Fixed now ! I used some ground loop isolators and OK now. Thanks ! Share this post Link to post Share on other sites
cctvnovice 0 Posted April 2, 2015 What ground loop isolators did you use? I am interested because I have a similar problem with images. Thanks! Share this post Link to post Share on other sites
SunnyKim 2 Posted April 2, 2015 Good to know. You mean that Grounding is as much important as Voltage supplier, as we experience sewage with our toilet. Clean flushing means clean video. Share this post Link to post Share on other sites
