crincones

Hello everyone, Would like to know what are the best practices for installing elevator cameras, recently had a bad experience installing wireless RF transmitters (about 500mW) for a 13 floor building.. the result was dissapointing. they seem to have some glitches (no video) when the elevator is moving, checked connections, tried to reorient antennas with almost no changes. you can take a look of the RF "transceiver" here: http://produto.mercadolivre.com.br/MLB-604416909-transmissor-e-receptor-sem-fio-video-audio-ate-1000m-12ghz-_JM I would like to know about your experiences for cabling, or wireless in this case. Thanks in advance from Brazil.

I am having the exact same problem, installing runs of about 90m, with cameras at every 10 meters or so, UTP for video and paralell wire at 12VDC for power.. had problems first with the UTP cable, buyed poor chinese cable, and after installing most of it and getting bad results, resolved to test the resistance.. for good quality UTP cable should be around 30 ohm every 300m.. my box of cable was incomplete (about 140m left) and tested it.. the brown and blue pairs returned 680ohm.. and the green and orange, around 220 ohm.. so.. spend a little more and buy some good quality UTP, made of COPPER, and not aluminium with copper surface.. (scratch it with a knife and will show).. well, second flaw. installed a long run of power paralell wire at 12V (longest run with 90m, same wire used in extensions), and tried to take power from it to the cameras, all connected in paralell with that wire.. horrible results, cameras worked like charm in daylight, but at night.. horrible noise.. the voltage dropped too much, to less than 10 volts.. (normal current consumption: 100mA daylight, 300mA night with IR on).. it is always good to test amperage before installing to make correct cable calculations.. bought something like AWG14 wire for power, but when tested resistance (after installng).. crappy results, like 4 times the expected resistance (chinese wire), resulting in something similar to an AWG20 wire.. So.. broke it at the half of the run, and installed a separated power supply (installation permitted it) for the second half of the run, and that solved the problem, but without discovering the cause.. the weird thing is that when I connected more than 4 cameras in the same power cable (even when testing the power supply in the center of the run (same distance in every directon), got noise in all of them, less than that, no noise.. thought the power supply was overloaded and injecting that noise, but tested amperage and got around 1.4A (for a 10A power supply), and normal voltage on load... I doubt I will try this paralell cable scheme, was not good at all, will try to stick to UTP cable using as many pairs as required for power.. calculating the maximum voltage drop, of course. my advice.. TEST YOUR CABLE if its from an unknown brand.. any clues of the weird interference? will be happy to hear about it..