video rolls over cat5

[ashtech 0]

hey guys,

 

I need some help. Im using the Eclipse ECL640 camera about 400 ft from the DVR. Im using aerial cat5 cable and a 24vac power supply which is separate from the video lines. i believe there are some 240vac lines in the ceiling where the video cables pass. I am using the eclipse ecl-btb passive video baluns and i get a lot of video rolls and even scrambled picture. Is this a ground loop? or some other problem? Ive also tried active receivers as well, i get a scrambled picture when i do that

 

Please help.

[Soundy 1]

Might be a silly question, but are you sure the polarity is right on the baluns? It must be the same at both ends.

 

Have you tried running the video over a different pair?

[Harrar 0]

Make sure your cat5 is not tied or running parallel to any power lines. If they have to be crossed, it should be at a 90 degree angle. Also make sure they are not laying on top of any flourescent fixtures.

[ashtech 0]

Yea, the polarity is correct, i even tried reversing it. I used the pair of blue/blue white for the positive and the green/green white for the negative.

 

Im not sure if it close to the florescent lights in the ceiling. and if it runs close to any power lines, what do i do? I dont quite understand the 90 degree bends.

[Soundy 1]

Yea, the polarity is correct, i even tried reversing it. I used the pair of blue/blue white for the positive and the green/green white for the negative.

 

That may be your problem right there: use only a single pair - blue for positive and blue/white for negative, for example.

[ashtech 0]

Thanks soundy, i will try this 2mr

[Harrar 0]

Im not sure if it close to the florescent lights in the ceiling. and if it runs close to any power lines, what do i do? I dont quite understand the 90 degree bends.

 

Sorry, I meant to say 180 degrees. Any power cable will generate a field which can be induced into a data cable close and in parrallel to it causing problems. Crossing at 180 decreases the induction potential considerably.

 

Of course, Soundy's recommendation of only using one pair will probably cure your problem.

[Soundy 1]

Im not sure if it close to the florescent lights in the ceiling. and if it runs close to any power lines, what do i do? I dont quite understand the 90 degree bends.

 

Sorry, I meant to say 180 degrees. Any power cable will generate a field which can be induced into a data cable close and in parrallel to it causing problems. Crossing at 180 decreases the induction potential considerably.

 

You had it right the first time: 180 degrees is still parallel.

[ashtech 0]

ok so this means that if i have to cross a power line, i cross it so that the power line and my video cable make a 90 degree? Im guessing it would be like a "+" my cable being horizontal and the power line vertical? am i on the right track?

[Soundy 1]

ok so this means that if i have to cross a power line, i cross it so that the power line and my video cable make a 90 degree? Im guessing it would be like a "+" my cable being horizontal and the power line vertical? am i on the right track?

 

Correct.

 

Theoretically, it's good practice to always do this. In reality, it's rarely a problem to run your signal beside 120/240VAC for short distances. Interference CAN be exacerbated by other factors, especially if you have weak signal or really long runs... and the level of interference will also depend on the actual current running through the power lines.

[ashtech 0]

OK, i tried using just one pair, I am gettin a picture now, but jus a few video rolls, a lot better than before, but for some reason, it scrambles now and again and comes back up?

Could this be a power line somewhere in the ceiling causing this? i have not tried the crossing method as yet. time does not permit it.

[Soundy 1]

See if you can correlate the "scrambling" to something environmental, like a motor starting up or high-power lights turning on.

[bongofury 0]

don't forget to try a small monitor near the camera and again near the dvr to see if it looks any better!

[empak 0]

Try using an active recever, I did a machine shop last year and it had mad power problems. The video cut in/out, rolled and there were humbars. I do admit that I put UTP to the test in there..... lots of splicing and long runs with the cat5e strapped to high voltage conduit and run in cable trays with lots shielded 220v AC . even long runs of 24v AC down the cat5e. the end result was a mess of very bad video. my first thought was to go to an active UTP setup. The ones I have are 12v DC, the thought of running power for each one was not making me happy. I placed the active receivers in first...... and stared in amazement ........ nice clean sharp pictures, with very little interference from the shops electrical wiring, the only thing that made some cameras video twitch was one of the big tig welders, and the shop owner had no problem with that. as the lights dimmed and the radio went blank when it was in use.

 

I would recomend to go acitive, just try the reciever first and then try the transmiter if you need it.

 

empak

[scorpion 0]

What are the cameras mounted to? Is this a metal warehouse style building?

 

Are you running between two different buildings, such as the DVR in one building, and the camera in another building?