January 16, 2015
Just installed another 5 camera's to a site. Had installed 5 new ones and replaced and old camera back at the begining of the year. Had no issues. Had cameras up to 300 feet on RG-59 and DC power. Been great so far.
So now they wanted to cover the rest of the rows of their self storage facility. Due to the lack a big enough conduit I had to do it this way.
There were already two existing cameras. From the DVR to them was about a 125 feet of CAT5 used for video. They both ran off one AC transformer. Each one used one pair of the CAT5e for video. The only conduit that went under the parking lot was 3/4 inch and had 3 cables in it. I tested the CAT5 and found one of the pairs bad so I had to replace that with Cat6e. That would run 4 of the 5 cameras which were a max of 150-200 feet in length to the DVR. The 5th camera is about 700 feet away. Used Quad shielded RG59 and used 26V AC power with a AC to DC adapter on the end. Funny because i though I would have an issue with this guy but no issue what so ever. Crystal Clear image (at least as clear as it can get with analog cameras). Well long story short whenever i have the other 4 cameras powered i get some pretty bad refresh like lines.
DAV video files can be looked at here http://ttz123.com/files/cameras/
One of the cameras I am seeing about getting RMA'ed (the Entrance Keypad) then the North East Camera is the 700 ft long run with no issues.
The rest have the weird issue. I have narrowed it to to power (I think). Now only one of them is running power along with the cat5 cable the rest have seperate power cables to a 9 port DC power box which was working fine. Now here is the thing. Before i went and ripped out all the old cabling I tested to see if I could get a few cameras to run on 1 power cable from the DC box. When i tested video one two of the new cameras using the existing power lines and video lines I got a perfect picture on the other end. So i didn't think i was going to have any issues. But now that it is all done and said i get that. I ended up not running power where I was orginally going to put it because i couldn't get enough cables though the conduit underground so i had to fix and outlet elsewhere that was closer and use that. Now here is what I do know.
I'm pretty sure it is power. When I power camera from Fluke Tester - Perfect image. When I use a 12v 1 amp DC adapter from a portable battery (It is a peak jumper battery with a AC outlet on it) It is fine. When I plug the 9 Port DC supply to the battery no change. When i use a extention cable with the DC adapter directly to the camera, no change. I though maybe where I was getting power from (which i had to replace the outlets) was dirty power. So tired using an outlet where it was plugged into before and the rest of the cameras are plugged into. No change. I even use a 26V AC with a AC to DC adapter and no change. Now the longest power run on these guys is 75 feet. Two more are about 50 and the other 25 or less.
Only when using the Fluke or the Portable battery with a single DC adapter does it show a good image on DVR.
Now power and video are in the same conduit. The issue has be bugged and this is the only thing in my way. I know it isn't an issue with the power and video being either on the same Cat5 as one camera is or not because when using fluke to test camera directly and use the existing power i get the same thing.
Any help would be great or advice. A little new on the camera installs but I have done a few but never had this issue before.
P.S. I know everything seems everywhere on here so if i'm a little unclear on things let me know.
If your not getting a voltage drop maybe your are not getting enough amps. The PSU may have enough to power everything per the specs, but testing with an amp meter will let you know for sure that cameras are getting the amps. Another thought is to use a TDR (Time Domain reflector) It tests the cable for any issues and lets you know how many feet down the cable the issue is. A TDR is not an inexpensive tool, but if you do cabling for a living its a tool worth having. I have found them for as cheap as 150$ and upwards of 10K$. Price varies on cable type and how many different cables it can test.
Electricity is like water in the idea that it takes the path of least resistance. Possibly there is something about your connections that are adding resistance to that circuit. A bad bnc or pt-3/4 would do it.