zilla

Just finished installing all of the cameras, except replacing the old ones in the elevator. I have a real bad video interference problem in the elevator cameras. Building is 23 floors, wire schematic: from elevator cabin to elevator equipment room on 2 pairs shielded elevator multi conductor wire, on the roof there is a splice to Coax RG-59 which goes 23 floors down. I have tried the following, to resolve the issue but nothing seems to be working. Any suggestions would be greatly appreciated. 1. Replaced / Installed different types/brands of analog cameras 2. Installed Ground Loop Isolators 3. Tested both of the cables for damage 4. Tried to move cameras around elevator, and put something in between (wood block, plastic, rubber) 5. Ground cable, cameras 6. Tried different types of video baluns 7. Completely isolated cable with special foil tape and verified that they are away from any AC voltage, Motors and so on 8. Tried cameras with no IR and plastic housing 9. Redone the connectors 10. Tried other power supply sources

Greatly appreciate for everyone's responses, will keep you posted on this case Thanks

Thanks for your response will try it out!

Any of you Gentleman's have tried implementing long range 802.11N wireless bridge into elevator to transport video signal. My biggest concern is signal bouncing and EMI.

Elevator company prohibited using those for some of the reason

Unfortunately powering cameras up in the elevator cabin is the only source, otherwise elevator company would have to re pull dedicated wire for it. Pairs for the video are the spare pairs from the multi conductor wire of the elevator it is NOT a cat5 cable. Otherwise I would try installing ip cam.

That's the key, right there. Break it down piece by piece to find where the problem is. Gentleman's I have tried to brake it down by pieces as you suggested, on the local monitor or CCTV tested interference is not as visible as on the monitor which connected into dvr

1 wire for video+ and 1 wire for video -

Thank you for all of your responses. Cable that goes from elevator cart to elevator equipment room on the roof is a shielded 2 pair wire that been pulled during the construction for extra phone line in the elevator. On the roof it converts, using video baluns from two pairs into S.Coax RG59 which goes 23 floors down into encoder. 1) I have tried using different types of video baluns, (including Speco, Pelco and etc.) didn't see to much improvement 2) Cameras powered up from the elevator cabin it's self, voltage is stable at 12.2 -12.3 vdc, even when it's traveling. 3) I have broken down cable testing by areas, on the CCTV tester interference is not as visible as on the monitor of DVR. 4) I tried different types of cameras, with different specs and housing 5) I have verified that cable is not to close to any AC noise Completely running out of ideas, all of your suggestions greatly appreciated!