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I have a pc based with an Eyemax 9120 that's going to have a max of 8 cameras. I need to know if Eyemax will allow recording at the same time on two hard drives (recording on a hdd internally and one externally), like geovision does. This is so if someone takes the computer the external hard drive will be left with recording because it will be mounted. Thanks.

Thanks for the reply. My buddy got Geovision to record to two hard drives at the same time, but I'm not sure if that's a Geovision thing or, like you said, a usb raid. For now, I've resorted to just writing to the external usb hard drive. However, the customer wants the hdd in the attic... which is going to require an extender because usb isn't powerful enough to push 10+ feet. Has anyone experimented with eSATA raid and Eyemax or Geovision?

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.

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...

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?

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?

Electricity goes by the way of least resistance [when comparing different conductive materials], although not linearly. All that insulating might decrease your chances of complete destruction, but I think the best solution is to get a lightning rod and ground it via heavy guage wire rope to a reliable ground source like a water pipe... away from the cameras that is. Mount the rod 7-20 feet away and above (radially) the camera and you won't have an issue with plasma burns or heavy voltage loads jumping at your camera. You may be asking why this will work, and the answer is simple. You are comparing the resistance of humid air to iron, not the aluminum siding of your building. Just a thought, because although you can't stop lightning, you can divert it! ========================================== Rochester/ASU ME/ECE/PHY 2009