cookm 0 Posted July 22, 2016 Hi guys, has anyone else had problems with wavy vertical lines appearing on some channels when using lots of cameras (> 10)..? I'll try to post a picture later if I get any responses... Thanks, Martin Share this post Link to post Share on other sites
msecure 0 Posted July 24, 2016 Hi guys, has anyone else had problems with wavy vertical lines appearing on some channels when using lots of cameras (> 10)..?I'll try to post a picture later if I get any responses... Thanks, Martin What type of cable and how do you power the camera? Share this post Link to post Share on other sites
cookm 0 Posted July 24, 2016 I am using one Cat5 cable for every 3 cameras of my setup with AHD/TVI baluns each end. So that's 3 cameras per 3 pairs of each cable. The fourth pair of each cable I use to send 24v DC down and then regulate down to 12v DC to feed the 3 cameras. I know this is not exactly the industry standard way of doing things with CCTV but it did seem to work well...or at least I thought it did until I noticed the interference on some of the cameras..! One group of 3 cameras is a lot worse than the others, and it is the longest run too (approx 80 metres). I have attached a night-time screenshot, which is when the problem is much more noticeable. Thanks for your time, Martin Share this post Link to post Share on other sites
msecure 0 Posted July 24, 2016 I am using one Cat5 cable for every 3 cameras of my setup with AHD/TVI baluns each end. So that's 3 cameras per 3 pairs of each cable. The fourth pair of each cable I use to send 24v DC down and then regulate down to 12v DC to feed the 3 cameras. I know this is not exactly the industry standard way of doing things with CCTV but it did seem to work well...or at least I thought it did until I noticed the interference on some of the cameras..! One group of 3 cameras is a lot worse than the others, and it is the longest run too (approx 80 metres). I have attached a night-time screenshot, which is when the problem is much more noticeable. Thanks for your time, Martin Full copper Cat5e? Did you try to remove the other 2 camera in the 1 cat5e 3 camera run and see if a single camera will be better? Share this post Link to post Share on other sites
cookm 0 Posted July 24, 2016 Yes, definitely full copper Cat5 cable (I don't do CCA). Yes I did try with just one camera and yes it was better so I guess it could be to do with the extra current drawn by 2 extra cameras and why it gets worse when IR cuts in at night... Share this post Link to post Share on other sites
tomcctv 190 Posted July 24, 2016 Hi. Looks like a power problem You can't run 24v down 1 pair of cat5 Share this post Link to post Share on other sites
cookm 0 Posted July 24, 2016 Hi Tom. Why not? So long as the regulator gives out 12vdc for the cameras I don't see the problem..? Thanks, Martin Share this post Link to post Share on other sites
tomcctv 190 Posted July 24, 2016 Hi Tom. Why not? So long as the regulator gives out 12vdc for the cameras I don't see the problem..? Thanks, Martin With your 24v how many amps ? ... You are looking at 80m with only 1 pair .... It is not going to work Share this post Link to post Share on other sites
cookm 0 Posted July 24, 2016 I have worked out that the current draw on the 24v side is around 700mA, so with approx 15 ohms drop over the feed and return legs of the Cat5 gives a volt drop of 10.5v which I admit is very close to the regulator's limit to provide 12v output. Nevertheless, I have done some tests where I have lowered the supply voltage to 3 Hikvision Turbo HD cameras to nearly 5v and they still work perfectly..! No sign of any interference patterns at all, so that's why I'm at a loss as to where it is coming from... Share this post Link to post Share on other sites
tomcctv 190 Posted July 24, 2016 I have worked out that the current draw on the 24v side is around 700mA, so with approx 15 ohms drop over the feed and return legs of the Cat5 gives a volt drop of 10.5v which I admit is very close to the regulator's limit to provide 12v output. Nevertheless, I have done some tests where I have lowered the supply voltage to 3 Hikvision Turbo HD cameras to nearly 5v and they still work perfectly..! No sign of any interference patterns at all, so that's why I'm at a loss as to where it is coming from... You are still not giving what amp is the 24v power supply . Are you using 18 or 24 cat5 80m is 265ft Share this post Link to post Share on other sites
cookm 0 Posted July 24, 2016 Sorry, I should have said it is a 5A 24v supply and I think it is 24 gauge Cat5. Anyway, I measured 15 ohms round trip resistance over the 80 meters distance... Share this post Link to post Share on other sites
tomcctv 190 Posted July 24, 2016 Sorry, I should have said it is a 5A 24v supply and I think it is 24 gauge Cat5. Anyway, I measured 15 ohms round trip resistance over the 80 meters distance... Then you need a better multi meter ....... Take a look at this and it's low. Share this post Link to post Share on other sites
cookm 0 Posted July 24, 2016 Sorry Tom, perhaps I didn't explain things very well. The 24v power supply is capable of 5A total max output. However, the actual current drawn down the Cat5 pair is only around 700mA... Share this post Link to post Share on other sites
Securame 0 Posted July 25, 2016 Running the power for 3 cameras on a single pair, that is your problem, and not the DVR. Share this post Link to post Share on other sites
cookm 0 Posted July 25, 2016 Thanks Securame, but can you explain why? Notwithstanding the above discussions... Share this post Link to post Share on other sites
tomcctv 190 Posted July 25, 2016 Thanks Securame, but can you explain why? Notwithstanding the above discussions... Why are you not taking any notice ?? 265ft The conductor is too small for that distance and remember you are on 24 1 pair is not going to work Share this post Link to post Share on other sites
cookm 0 Posted July 25, 2016 With respect I was taking notice of all replies so far. It's just that everyone just says "it won't work" without explaining why. I have already done tests simulating low voltage at the turbo HD cameras and they simply just do not behave in the way mentioned in my original post. Sorry to sound anal but I was really hoping someone could say something like "oh yes I've seen that behaviour before and it's due to crosstalk" or something like that. Thanks for your patience. Martin Share this post Link to post Share on other sites
tomcctv 190 Posted July 25, 2016 With respect I was taking notice of all replies so far. It's just that everyone just says "it won't work" without explaining why. I have already done tests simulating low voltage at the turbo HD cameras and they simply just do not behave in the way mentioned in my original post.Sorry to sound anal but I was really hoping someone could say something like "oh yes I've seen that behaviour before and it's due to crosstalk" or something like that. Thanks for your patience. Martin IT JUST WONT WORK WOW. FIRST 270ft on one single pair of 24 cat5 24v 5amp .........this is out of code ....also none regulation. And unsafe. Run a power extension to test and if your cameras have the same problem But 24v 5amp over 1 pair is not the right way Share this post Link to post Share on other sites
Securame 0 Posted July 25, 2016 I know this is not exactly the industry standard way of doing things with CCTV but it did seem to work well...or at least I thought it did until I noticed the interference on some of the cameras..! One group of 3 cameras is a lot worse than the others, and it is the longest run too (approx 80 metres). Trying to power 3 cameras over a single Cat5 pair, 80 meters. Good luck with that. One pair for video, and the other 3 pairs for power; that would be a good way of doing things if it was only for one camera. If you want to go up to 4 cameras, then use the 4 pairs for video, and use a different run for power. Share this post Link to post Share on other sites
cookm 0 Posted July 25, 2016 Thank you for your comments guys. Martin Share this post Link to post Share on other sites
