White noise?

[PiDGE]

Can someone tell me possibly what would cause static interference on my cb or a cb in general. I'll try and explain...I've got a blue sea fuse panel running the cb, front fogs, rear back up lights, and a relay. The problem starts when I put the truck into reverse with the cb on. With the cb on u get a white noise/static thru the speaker. The aux. back up lights come on and the noise starts. I've gone thru the wiring and stuff looks legit. If I pull the fuse that feeds the relay for powere to the aux. rear backups it dosent make the static/white noise. I'll note that the magnet on the relay is triggered by the factory reverse lights. Could a relay going bad give these noises thru my cb? It perhaps a powere and ground touching? Any ideas what would make this noise thru the cb?

[BigRed44]

that sounds more like the lights them selves i'd try disconnecting the aux lights and see if you get the same result.

[PiDGE]

Yeah did that BigRed. When they were disconnected it did go away. Something todo with those lights I spose. I went thru the wiring to make sure nothing was crossed, touching, or whatever as I suspected something would be, but all appears to be fine?? Weird thing is when I use to run regular fogs for the backups I never had this issue. Only when I switched to little 6" LED bars did this start. Maybe the LED's make it act up? I don't know?

[BigRed44]

Could be a loose ground between what ever the bars are attached to and the frame that's what usually causes noise in electronics.

[PiDGE]

Not sure BigRed. Their mounted to the fibreglass cap, but I've got the neg. wire run to a good ground on the body. Know what I mean?

[FrontyFlyer]

Body to chasis ground issue maybe?? try grounding the body to the frame with a jumper cable and see if the noise goes away. I had some wierd whine coming through the speakers, it was from a corroded body to frame ground wire.

[PiDGE]

I'll give that a shot F.F.

[buttsy]

Could be a sub par connection in the light body too. That'll require taking the housing apart though. I'd leave that for after the body ground test.

If you haven't already you should run the CB ground to a ground point as close as you can to the CB that nothing else is grounded to. Make sure you aren't grounding it to a terminal bar or similar.

Lastly: a relay is an electromagnet, so if it's in proximity to the CB, antenna cable, or power cable it could be inducing a signal in the wire.

This post has been written entirely in recycled electrons by a bonehead on a Galaxy S4. Also from inside an igloo. Why not, I'm from the "North" right?

[PiDGE]

Thanks Snafu for the tip. The relay I can tell you is tucked away behind the tail light housing. Powere for both the cb and the relay are off the same aux. fuse panel, but on seperate terminals if you can follow what I'm trying to say. The CB is grounded off a screw somewhere behind the dash in the radio area as they both sit one on top of another. I did replace the relay figuring the magnet/coil was to blame, but no dice. I should mention also I've got some LED strips on the inside roof if the cap for lighting. That power is just taped off the 10 gauge feeding the relay for the reverse lights and go thru a switch without an relay feeding those. I've gone and pulled everything apart trying to eliminate the source which all points back to the reverse LED's. Noise goes away when the relay/reverse lights are takin outta the equation I found. I'm thinking the LED's must be different internally than regular fogs as the old fog set up never did this. I will pull the dash and have a look at the ground for the CB and try to move it around to see if it makes a difference.

[buttsy]

I meant if the relay is close to anything to do with the CB it doesn't have to be bad to
effect it. The ground wrap in the coax cable should cut it down, if it's the antenna cable. Any wire that isn't ground wrapped can have signal induced by the current flow through the relay activation coil. Could also be interference back feeding through the power leads. Try the CB connected to another power source, ideally right to the battery for testing purposes, then try the reverse lights again. If there's no noise you'll know it's interference through the positive bus in the panel.

This post has been written entirely in recycled electrons by a bonehead on a Galaxy S4. Also from inside an igloo. Why not, I'm from the "North" right?

[Nd4SpdSe]

I agree with Buttsy on that. Typically it's a grounding issue. Also keep the grounds as short as possible. I was on XN last week and one guy who "seemed" knowledgable in his post had suggested to run the ground directly back to the battery....that's where'll you'll definitely get noise.

Could also try to run some power directly to the lights bypassing the relay, see if that changed anything.

[PiDGE]

Oops sorry Buttsy. Why was I thinking Snafu??? Lol

[PiDGE]

Oops sorry Buttsy. Why was I thinking Snafu??? Lol. Krown fumes.

[Morpheus]

If you're running LED's now, get rid of the relay, they are redundant. The LED's draw no power, as long as the circuit is fused, that's all you need.
The relays are a must for aux halogen bulbs, but you can run the LED's right off the reverse light circuit with zero impact.

That alone may eliminate the extra circuitry that could be causing your noise.

[PiDGE]

I was thinking about that to Morpheus. I'm aware of the little draw they have, just that I left the relay their for no apparent reason after I replaced the standard fogs. Next warm dry nice day I'm going to dig into it again and see whats up.

[PiDGE]

Tried the ground to body trick with no different results Fronty Flyer. On the other hand I did post up in another fourm after someone had posted up the exact same white noise question and it seems to do with LED lights the root cause of the problem. I don't know the specifics, but googled the same thing and came back with multiple problems regarding LED lights and radios. Even cordless phones can be affected in homes with LED's I've read. Apparently there know for causing interference with eltroinics. Who knew?

[buttsy]

Some LED lights use drivers to control brightness. They operate at frequencies starting around 30MHz, and CBs operate between 26 and 27 MHz, so that could be your issue. A solution you might consider is getting an EMI choke (like this, and putting it around your Power lead. It's an inexpensive solution... What is the make/model of the LED lights?

[PiDGE]

Thanks Buttsy I'll have a look into that. The lights themselves are BlitzPro and there of the 6" long bar type variety. Kinda the BarginHarolds of LED bars, but they work, are bright and haven't had water issues in over a year.

[buttsy]

More thoughts: How close to the LED lights and their power leads does your antenna cable run? You may want to consider running differently if it runs close to them. I'd also test the continuity of the ground wrap on the Coax antenna lead. If it has more resistance than say an ohm, replace the cable. Another option you may want to consider is changing the Coax Antenna lead with a Triax cable and ground the outer shield straight to ground. I think I still have Coax ends and a crimper somewhere around here. I can prep a Triax and get it to you somehow if that's an option you are thinking of entertaining... If I can find some...

[buttsy]

Just looked at the Lights on the web here, and I'm 99% sure it's got a driver. LEDs only function in a very specific Voltage range. White usually use 3.5V or there abouts. Run 3 LEDs in series and you get about 10.5V, 4 and it's 13.5V. Battery alone will run between 11V and 12V, the Alternator 14V. To steady out the power to run your lights through a wide voltage range, they install a driver (which is also why you have heat syncs on the back of the light housing). This allows every LED to be connected separately and run by the optimal voltage. Bad part is that improperly shielded drivers generate Electromagnetic interference. So, short of opening up your light housing, or building a Faraday cage around your lights, there's not much that can be done from that end. If the Choke doesn't work, you're going to have to run different power source for your light and radio. Ideally the CB should be run on it's own feed right to the Battery, and grounded as close to the radio as possible. There are ways of cleaning up noise in the power feed, but they can get expensive. As I mentioned, Triax cable will give you a grounded shield around your Antenna. Those two things together should get you cleared right up.