GrMt 0 Posted October 26, 2008 Hello everyone! My first thread and hope it's in the right section. Tried to find help on this issue but to no avail. Some on my background. Mechanical and Electrical Engineering at University of Rochester and finishing up in Arizona State University (my homestate). Way more Mechanical than Electrical tho... Okay so my setup specs: Lorex QLR1660 PCI 16 Channel Card (... yeah Lorex... it was last minute at Frys) More than powerful enough computer Super Circuits Camera (x15) Auto-Iris and brightness adjusting camera for store front (x1) 16 outlet 24VAC (all getting 24.0+ volts AC at cameras) All connected via BNC crimped and confirmed (not siamese) Now my problem: Both on the computer monitor and splitter/booster (for the 47" flatscreen cashier) show some camera's displaying wavy distortion every now and then. My first assumption is that it's comming from RF interference when the signal is being brought to the computer. The only way to reduce this or even get rid of this is to rewire with fully shielded COAX or CAT5e (A lot of work), or use ferrite chokes which can be pricy for 16 COAX's and depending on how many windings. BUT NOW im thinking, wait... this is COAX, it is already shielded and im in a building with aluminum struts that should block out some RF from the outside... Now im just confused as to why im getting this wavy distortion. Hooking up a camera next to the computer seems to not have any distortion which led me to believe its the COAX. Could it be my inferior Lorex PCI card? It was a last minute decision and $500... Share this post Link to post Share on other sites
ak357 0 Posted October 26, 2008 Hello everyone! My first thread and hope it's in the right section. Tried to find help on this issue but to no avail. Some on my background. Mechanical and Electrical Engineering at University of Rochester and finishing up in Arizona State University (my homestate). Way more Mechanical than Electrical tho... Okay so my setup specs: Lorex QLR1660 PCI 16 Channel Card (... yeah Lorex... it was last minute at Frys) More than powerful enough computer Super Circuits Camera (x15) Auto-Iris and brightness adjusting camera for store front (x1) 16 outlet 24VAC (all getting 24.0+ volts AC at cameras) All connected via BNC crimped and confirmed (not siamese) Now my problem: Both on the computer monitor and splitter/booster (for the 47" flatscreen cashier) show some camera's displaying wavy distortion every now and then. My first assumption is that it's comming from RF interference when the signal is being brought to the computer. The only way to reduce this or even get rid of this is to rewire with fully shielded COAX or CAT5e (A lot of work), or use ferrite chokes which can be pricy for 16 COAX's and depending on how many windings. BUT NOW im thinking, wait... this is COAX, it is already shielded and im in a building with aluminum struts that should block out some RF from the outside... Now im just confused as to why im getting this wavy distortion. Hooking up a camera next to the computer seems to not have any distortion which led me to believe its the COAX. Could it be my inferior Lorex PCI card? It was a last minute decision and $500... Lorex Technical Support call 1-888-42-LOREX(56739), option 1,1 Super Circuits 877-995-2288 Frys Sales and Customer Service - service@outpost.com Toll-free (within U.S.): 1-877-688-7678 or 1-800-856-9800 Share this post Link to post Share on other sites
scorpion 0 Posted October 26, 2008 What kind of power supply are you using? Can you take some of the cameras off the power to see if it clears up? ____________________________________________________________ Is the coax copper center, and is the braid copper? _____________________________________________________________ Do you have a loop in and loop out situation such as going through a multiplexor, and then going to a DVR, (or vise versa)? ____________________________________________________________ Does it clear up using a tube (CRT) based tv rather than a flat panel screen? Share this post Link to post Share on other sites
GrMt 0 Posted October 31, 2008 What kind of power supply are you using? Can you take some of the cameras off the power to see if it clears up? ____________________________________________________________ Is the coax copper center, and is the braid copper? _____________________________________________________________ Do you have a loop in and loop out situation such as going through a multiplexor, and then going to a DVR, (or vise versa)? ____________________________________________________________ Does it clear up using a tube (CRT) based tv rather than a flat panel screen? Thanks for the reply! Taking Cameras off seems to fix the issue. I am using COAX copper center with copper braid. I do not have it going through a multiplexor, just to the DVR card on the PC. Finally, I am using an AC 24 Volt (x16) mfg by MG Electronics. I've checked the voltage and amperage on the circuits, and they are all getting a steady stream... What do you think? Share this post Link to post Share on other sites
scorpion 0 Posted November 1, 2008 It sounds like a power problem. I am going to go with the assumtion that the power supply is being over drawn. You may have to get another power supply to power the unconnected cameras, or you will have to upgrade the present power supply. For the DIY that is reading this post here are some troubleshooting tips. Reading your data sheet for your power supply may show that you have enough of a rating on paper, but this may not be the case in the real world, or your cameras may state in the data sheet how much they use, and they may use more then the data sheet shows, or you could have both scenerios. It may be that one (or more) cameras may have a problem. The camera is working, but it may be on an apogee where it will soon "burn out". I would add some cameras back to the system until you have a problem. Take the last camera connected that starts the problem, and remove it, and go on to the next camera. If it works ok as you are adding cameras then one would have to assume the power supply is ok, and that this one camera is bad. You may get to a point where the last camera connect causes chaos, and every camera that is swapped at this point continues the chaos, then it would be assumed that the power supply is the culprit. If every thing is working fine, and you only had to remove one camera then do not be fooled if everything is working great! AT night when it gets dark the IR LED will come on, and draw more power sending everything back in to chaos again, so make sure you are on sight at dark (or remote in to check video) to verify that everything is working correctly. Also power supplys may work when first applying power, and as it "warms up" then the problem may reappear, so do not be fooled by a "everything is working when I plugged the power supply back in" routine. Trust, but verify as Pres Reagan says! What do you think? Share this post Link to post Share on other sites
GrMt 0 Posted November 1, 2008 Great feedback. This forum rocks and I'm lucky to have found it! I'll be investing in another power supply to prevent this one from being over drawn. When I checked the power supply previously, I was starring at the screen for over 10 minutes without any wavy action. However, when I powered up all the camera's the problem occurred every now and then. For some reason all of my camera's are over drawing their voltage a bit (1/2 volt or so), so then this makes sense that the power supply would be working harder and shoot voltage flux to my cameras. I also have unshielded copper coax wires running right over the fluorescent lights (not all but some) from the cameras to the DVR (EMI & RFI?), would investing in ferrite chokes increase my clarity/take out the static? Share this post Link to post Share on other sites
Lolo Wolf 0 Posted November 1, 2008 GrMT wrote:"I also have unshielded copper coax wires running right over the fluorescent lights" You need to pay close attention to bend degree and bend location with your coax as well your runs should avoid AC power lines and fluorescent lights - after you troubleshoot your power issues (noted by Scorpion) I would revisit all your paths perhaps that is adding to your quality issues - conduit and/or cable tray is optional depending on the individual building requirements. Regards Share this post Link to post Share on other sites
scorpion 0 Posted November 1, 2008 What is unshielded Copper Coax? If there is not shield then what is the grounding wire of that circuit? Share this post Link to post Share on other sites
GrMt 0 Posted November 1, 2008 What is unshielded Copper Coax? If there is not shield then what is the grounding wire of that circuit? Regular Coax I suppose (ALL copper, not the steel w/ copper coat). Shielded coax that I've seen and used is regular coax (copper core, dielectric, braided copper, cover) with an additional aluminum film around another dielectric with the final covering wrap all around that. It uses the Faraday Cage principle, however I've seen people just attach it to a BNC without peeling some of it away and grounding the aluminum. If you ground the aluminum on the run of coax you can cancel any Electromagnetic Interference to the coax. To ground it, I simply take a strand of twisted pair and twist it around an exposed piece of aluminum (from peeling away the outer plastic) and attach the other end to a ground source (switch box, etc.) NOTE: you should NOT include the aluminum in the BNC connections or any connection, due to the difference in resistances of the two metals. (Bad things: static, etc.) It'll still act as a shield if not grounded, although not as effective (might as well stick to regular coax for its own shielding properties in that case) These coax wires that I'm currently using are not shielded. Hope that wasn't too jumbled... What about the Ferrite Chokes? Does anyone use them for their cameras? I only do these camera installations for my parents and their business friends, all in retail. So it's more of a hobby for me. Share this post Link to post Share on other sites
