ofineo 0 Posted August 23, 2012 Sorry if it sounds a basic question. I have had some problems with a system that i did not installed, and after checking on the scope several of the cctv cameras are way less than 1Vpp and sync pulse are obviously less than 0.3v. The cables that are installed are CAT5 and the picture is no too bad but it creates some issues with the DVR which is a DM unit. For example every month a camera image duplicates on another channel.. I thought increasing the gain in the camera, some of the cameras have this facility in the camera menu, would increase the Vpp but it only wash out the picture in the monitor. How can i increase the Vpp or the Sync pulse that i get in the DVR end? Do i need an amplifier? Share this post Link to post Share on other sites
survtech 0 Posted August 23, 2012 On most camera systems, you can't increase the output voltage. There are equalizing amplifiers for analog video (see Pelco EA2010 here http://www.pelco.com/sites/global/en/products/video-transmission/range-presentation.page?p_function_id=10517&p_family_id=10301&p_range_id=5607), but they tend to be expensive (~$150 each) and you would need one for each channel. You might be better off considering active receivers instead of passive baluns at the DVR end if your cable runs are long enough to cause a drop in the video signal level. They would probably do a better job than amplifying the video signal with amplifiers. Share this post Link to post Share on other sites
GrouchoBoucho 0 Posted August 23, 2012 The cables that are installed are CAT5 and the picture is no too bad but it creates some issues with the DVR which is a DM unit. For example every month a camera image duplicates on another channel..did they actually use baluns or are the wires just spliced in directly? if they did use baluns, did they use only one pair for video? sounds like something else is goofy. after checking on the scope several of the cctv cameras are way less than 1Vpp and sync pulse are obviously less than 0.3v. maybe the cameras are failing? Share this post Link to post Share on other sites
ofineo 0 Posted September 13, 2012 Hi thank you for your replays. to your question, yes the cameras use baluns to convert the bnc to CAT5 and there is a 16 channel balun at the DVR end to convert it back to bnc just before it goes into the DVR Share this post Link to post Share on other sites
the toss 0 Posted September 13, 2012 1Vpp is only a nominal signal level & some cameras output less than this. Share this post Link to post Share on other sites
ilk 0 Posted September 17, 2012 1Vpp is only a nominal signal level & some cameras output less than this. But the sync pulse should always be 0.3v If the the sync pulse is too low or too high (or the incorrect shape) DVRs may not recognise the signal as video. Try using a known source like a pattern generator instead of the camera and this will tell you if you have an issue with your transmission system. Ilkie Share this post Link to post Share on other sites
