Need Help with Horizontal Lines

[tonyvol 0]

Hey guys, I'm getting horizontal lines on my cctv security system. I'm using a Altronix (ALTV2416) 24VAC 16 camera power supply. When I hook 4 cameras up to the power supply by just using the camera power leads that are attached to the cameras, I have no horizontal lines on the monitor. But when I extend the camera some distance using 18/2 power wire I get lines. I'm also using shielded cat 5e cable for the video. I have one camera that is 75ft, one 150ft and another is 500ft from the DVR and the power supply. The 500 ft camera is being powered with 14/2 wire to account for voltage drop. The power supply has two transformers and if I hook the cameras to the same transformer I get lines. If I hook one camera up on one transformer and the another up to the other transformer then picture looks good with no lines. I've trying to figure out what the problem is for a couple of weeks, but I can't figure out what is causing the lines. BTW. it is worst when it is dark and the IRs are on. One guy mentioned that I need a isolated power supply like the Altronix ALTV2416ULCBI. Not sure if that will fix my problem or not. I've also tried a ground loop isolator but then I wasn't getting a video signal.

 

Thanks,

Tony

[nifter53 0]

Try this to start. Power up just one camera at a time and see if the lines are present on all, some or in some combination.

 

If you isolate it to one camera, power that camera from a separate power supply. Also, are any of the cameras mounted onto/touching metal that could be linked to ground?

 

What kind of baluns are you using? Have you tried swapping those? I've noticed poor quality with cheap or mix and match baluns.

[tonyvol 0]

Try this to start. Power up just one camera at a time and see if the lines are present on all, some or in some combination.

 

If you isolate it to one camera, power that camera from a separate power supply. Also, are any of the cameras mounted onto/touching metal that could be linked to ground?

 

What kind of baluns are you using? Have you tried swapping those? I've noticed poor quality with cheap or mix and match baluns.

 

Thanks for responding. I tried to isolate it to one camera, but it seems like when I hook up two or more camera to the same transformer on the Altronix power supply I start seeing faint lines. The camera are mounted on 4x4 wood poles. Maybe it is the video baluns? The camera that is 500ft from the power supply seems to make it worst than the others. But without that camera hooked up, I still have faint lines on the monitor.

 

I'm using these video baluns.

http://www.securitycameraking.com/passive-video-balun-57337-prd1.html?pSearchQueryId=2687530

 

Thanks,

Tony

[nifter53 0]

1) Is the cat5 shield touching (grounded) to any of the equipment? Try ensuring it is not touching/grounded on both ends. Try grounding just one end (via Drain wire) to dissipate the RF to ground.

 

2) Are you using just 1 pair of wires for the balun? i.e. use just blue + white/blue. Do not double-up (use multiple pairs)

 

3) You could try using a ground lifter on the DVR to see what effect it has on the noise.

[tonyvol 0]

1) Is the cat5 shield touching (grounded) to any of the equipment? Try ensuring it is not touching/grounded on both ends. Try grounding just one end (via Drain wire) to dissipate the RF to ground.

 

2) Are you using just 1 pair of wires for the balun? i.e. use just blue + white/blue. Do not double-up (use multiple pairs)

 

3) You could try using a ground lifter on the DVR to see what effect it has on the noise.

 

 

1) I checked and the cat 5 isn't touching any of the equipment. How would you go about grounding using the drain wire if I don't have a ground port on the DVR?

 

2) I'm using just the blue wire for the positive and the blue/white for the negative on the video balun.

 

3) Could you point me to the type of filter you are talking about? I installed a ground loop filter but that didn't solve the problem.

 

One thing I forgot to mention is... I had to run the power wires and the cat 5 wires in the same pvc pipe going underneath a driveway. The only power wires in this pipe are to power the cameras. I was thinking that since I was using shielded cat that this would be ok.

 

I got some separate recptacle power supplies were each camera has it's own dedicated power source and the interference went away. I would like to have just one power supply to distribute the power(cleaner install and you have fuse protection). If I can get the interference to go away without buying another Altronix power supply that would be great.

[nifter53 0]

You have a classic ground loop. The reason the wall warts (110 ac adapters) work is that they eliminate the common ground.

 

A ground loop is just as its name implies. Current is looping through your equipment via a common ground. To elimate the problem you either.

 

1) change cameras to dual voltage 12vdc/24vac cameras which by design elimate ground loops.

 

2) determine which pieces of equipment share a common ground and remove the ground from one of them.

 

If you google "ground lifter" you will see an example. Looks like a an ad plug with no ground peg. It seems the logical answer is that your dvr and altronix are sharing ground and looping through the power ground and coax.

 

Think of it as an actual loop. Current is passing through the camera, back trough the power supply, into the ground, back into the dvr, out the dvr via the coax and back into the camera. Or maybe the opposite direction, but you get the idea.

 

When you switch to the power adapters, you removed the ground path shared by the dvr.

[tonyvol 0]

You have a classic ground loop. The reason the wall warts (110 ac adapters) work is that they eliminate the common ground.

 

A ground loop is just as its name implies. Current is looping through your equipment via a common ground. To elimate the problem you either.

 

1) change cameras to dual voltage 12vdc/24vac cameras which by design elimate ground loops.

 

2) determine which pieces of equipment share a common ground and remove the ground from one of them.

 

If you google "ground lifter" you will see an example. Looks like a an ad plug with no ground peg. It seems the logical answer is that your dvr and altronix are sharing ground and looping through the power ground and coax.

 

Think of it as an actual loop. Current is passing through the camera, back trough the power supply, into the ground, back into the dvr, out the dvr via the coax and back into the camera. Or maybe the opposite direction, but you get the idea.

 

When you switch to the power adapters, you removed the ground path shared by the dvr.

 

Thanks... I really appreciate your help with diagnosing the problem. I've been chasing this issue for quite sometime now. When the cameras are working during the daylight there are no line. When it becomes night, lines appear on the monitor.

 

1) The cameras I have will work with both 12DC and 24AC power.

 

2) The 24VAC power supply, the DVR and the monitor are plugged into the same 110V outlet. This outlet is a dedicated power source for the security system. Maybe as you mentioned this might be my problem. What do you think?

[nifter53 0]

If the wiring is to changing then the ground loop is present at all times. Most likely at night the ir LEDs are powering on and drawing more power thus generating more current in the loop. Also at night the b/w accentuates the horizontal lines on screen because the contrast is higher.

 

At this point I would say trying out a ground lifter on the dvr is your best direction.

 

The principles of ground loop causes are quite simple, Too many grounds. However, an easy solution is often difficult to implement.

[tonyvol 0]

If the wiring is to changing then the ground loop is present at all times. Most likely at night the ir LEDs are powering on and drawing more power thus generating more current in the loop. Also at night the b/w accentuates the horizontal lines on screen because the contrast is higher.

 

At this point I would say trying out a ground lifter on the dvr is your best direction.

 

The principles of ground loop causes are quite simple, Too many grounds. However, an easy solution is often difficult to implement.

 

Is this the ground lifter you are talking about? The only others I see seem like they are for audio equipment.

 

http://www.amazon.com/UL-Listed-Plug-Adapter-Convert-3-Prong/dp/B003C24UM2/ref=sr_1_3?ie=UTF8&qid=1359329917&sr=8-3&keywords=ground+lift+adapter

 

Also, I read that when you have all cameras hooked to a single power source you can get into a situation where the cameras are pulling different amounts of power and this can cause lines. Would the ground loop problem cause this? Today, I had 3 cameras that were in a daylight setting and 1 camera that was in a dark room. The lines on all 4 cameras were much worst. When it got dark and all cameras were in the dark, the lines got much better.

[nifter53 0]

Very interesting. I'm not experienced enough to comment on the voltage difference issue, but it could be a cause.

 

On another note, what kind of monitor are you using? VGA or bnc?

 

Can you try a different monitor?

With all cameras connected and in a state of displaying horizontal lines on the dvr. Can you then hook a monitor to each one individually and see the image? (bypassing the dvr)