Interference problem

[matt 0]

I've installed a 4 camera DVR system at my work. I work at an outside storage facility requiring runs over 200Ft so I used UTP for the outside runs. I'm using an Avermedia NV3000 card, but was first using a cheap card from eDigitalDeals.com (the software kept crashing).

 

I have good pictures during the day. Very little horizontal lines, good color, etc. My problem is at night. We have approx. 15 High wattage outdoor lights from the power company for our lighting. Every night when they start switching on the farthest of the two cameras (approching 600ft) starts getting more horizontal lines. After a few minutes and a few more light come on the software reports video lost.

 

The cameras are connected to a pair of 4-channel passive UTP hubs each (for expansion later), powered locally. Thay have between 10 and 15 ft of coax outside between the camera & hub and 3ft inside between the UTP hub & the DVR card. The cameras are approx 360ft apart connected to different hubs and run on different cat5e cables. ONLY the farther one has the problem.

 

I have already minimized a groundloop problem, but this one persists.

 

The following is an image of the problem:

 

I have a few questions:

1) What is the problem? (Interference, weak signal, ...)

2) Can it be solved with an Active Receiver?

3) Could it be solved with a Coax amplifier between the camera and the first UTP hub?

 

Any other suggestions would be greatful.

 

Thanks.

[VST_Man 1]

1) What is the problem? (Interference, weak signal, ...)

obviously the lights are interfering

2) Can it be solved with an Active Receiver?

active baluns should do the trick

3) Could it be solved with a Coax amplifier between the camera and the first UTP hub?

no......you'll only amp the bad signal

 

...... are you are running the video cables alongside or near the wires/lights?

 

...... is there a chance that the 600ft. camera also has a power roblem? Is it a IR type or just low light? what type power are you using? ac/dc? measure the power at the camera during the day and then at night.

 

.......also, powered locally? at the DVR, pushing power and video down the utp?

 

and lastly, what does "Very little horizontal lines" mean? The pic is slighty ok during the day, very little distirtion? a clear pic is a clear pic.....anything else is trouble which grows into larger problems over time.

[matt 0]

Would Active Receiver baluns work or do I need to do Active Transmitter?

 

The coax is not run alongside any power cables. But, the Cat5 is run in the same conduit as the AC power for the cameras. I thought that it might be interfering, so as a test I used two 12v batteries to power each camera and switched off the circuit. It did not help.

 

The 600ft camera is low light, 12v dc (from the same point as the balun, not from the DVR). I'll try measuring the power.

 

By "Very little horizontal lines" I mean that there is one very, very, very faint one that you have to get upclose to the monitor to see. It was worse, but I took one of the pairs of the cat5 and connected it to the negitive on all the power supplies and to the computer case to create a common ground. This relieved much of the horizontial lines from the other camera.

[rory 0]

Okay so the UTP/Cat5 is the long run about 600' right?

 

I would definately use some NVT gear with Interference Rejection and Ground Loop Protection, or some other similar gear, the cheap Hubs may not include that protection. Passive may work, though you WILL loose quality and can have issues, so I would personally not use Passive at that distance on both ends. Active will be expensive, for the good gear, but you are less likely to have issues.

 

What brand do you have there now?

 

With the NVT gear (not sure about the others), if you have a Passive Hub, you can just use Active Transmitters up to 3000', if you have a Active Hub you can use Passive Transmitters the same.

 

Powered Locally, you mean powered in the same area of the cameras, or 600' back to the DVR? If its 600' back to the DVR, then that in itself is a problem.

 

What type of camera is it? If it is an IR camera, at night when the IRs come on, they draw more amps. Hence can be the issue with powering it 600' away on cat5, if it was 18AWG you could get away with it.

 

To trouble shoot you would need to power the camera up at the camera itself, and look at the DVR monitor side. Still bad, check the video at the Camera itself, still powered at the camera. Still bad, hook up a camera at the point where the Cat5 joins the Coax, test it there and look at the monitor at the DVR. Stuff like this should be done before jumping on buying an expensive Active device or Amplifier.

 

 

Rory

[cctvron 0]

does the camera have a pal/ntsc switch???

[matt 0]

CCTVRON,

The camera does not have an NTSC/pal switch, and the box it came in is marked NTSC. Also, the camera works fine untill dark when something switches on.

 

rorry,

Unfortunatly I work for a company that won't spend the money on the expensive gear. I don't know the brand for the passive gear, but I bought it here: http://www.defencemeasures.com/dm-5464.html . Powered locally means at the camera. Camera is low light normal res.

As for your troubleshooting tips; there is less than 10ft of coax between the camera and the cat5, camera has always been powered at the camera.

 

 

Update, while I was out waiting for the lights to turn on to measure the power, VST_Man's suggestion. I discovered that the camera starts to cut out before the lights we added for the cameras come on. I've got an idea that something by the office is causing the interference. We have one of those cheap Halogen lights you can buy at Lowes/Home Depot on our sign, I'm wondering if that is the source. I'm going to disconnect it and see if it still happens.

Also, I just found out today that one of the ports on the DVR card has stopped working. It happends to be the port that this camera was connected to. I've already requested an RMA to exchange it.