HAM interference with fog lights?

[Louisiana Overland]

Just turn the fog lights off when on the radio. You still have your main lights.

Bad pulsewidth power supplies on LED's usually can't be fixed. Grounding, rerouting wires, nothing. Crazy bad THD. It's becoming a nightmare in the industry. Building electric demand drops nicely, but THD goes through the roof and can screw up dimmers, UPS's, even backup generators.

Even high end Rigids have this issue. Cheap chinese lights, haha, forget about it.

All of my mains are halogen, my aux lights are led and halogen. All aux are off when the radios on.

I appreciate and experienced HAM who has had the same issue chiming in on this. As a newb, it had me scratching my head as to what I was doing wrong. I do have a 2awg battery cable to re route and that still stands a chance to help, but you are right... clear as a bell with the fogs “off”. I still wish I could find someone in my area to teach me more about the radio.

 

[MidOH]

Do you have an aux battery on a relay isolator for a camper or winch?

I had a relay that would isolate my aux battery. Then I'd power my CB from that. Was ok, until that battery got low.

 

[Louisiana Overland]

Do you have an aux battery on a relay isolator for a camper or winch?

I had a relay that would isolate my aux battery. Then I'd power my CB from that. Was ok, until that battery got low.

no sir. I took another route and did a beefed up single battery set up.

 

[MidOH]

That's the route I'm going with my current truck. Single alt, one b+ for simplicity.

When LED's first came out, I was excited because of the reliability offered. But then they failed, because they couldn't handle fluctuations in power supplied from the vehicles alternator.

So it was a race between engineers that could make an LED that was military tough with no power supply, and engineers that could make a pulsed power supply. Even though overlanders duct taped the power supply engineers to a campground light pole and beat them with Maxtrax and winch ropes.........the power supply engineers won.

Now every industry in the entire world, that requires light, has to suffer because some overlanders didn't bring a chainsaw to a party.

 

[Prerunner1982]

You might also try RF Bonding, using braided ground strap to connect the isolated metal parts of the vehicle to the main body of the vehicle such as the hood, rear hatch, and exhaust. The pieces can act as an antenna for the RFI, RF bonding may help to mitigate that. It also helps add to the ground plane properties of the vehicle, though not quite as important for VHF/UHF as they require minimal ground plane. You can get rolls of braided ground strap on amazon.

 

[MidOH]

Lot's of good tips in this thread worth trying.

Rigid LED light causing radio interference??

Hey guys, I recently installed my HAM radio setup and noticed that when I turn on either of the Rigid LED lights (forward facing dually's or a rear faced dually) I get interference on the radio, I have to turn up the SQL to avoid listening to the noise.. I had a friend complain about a year...

expeditionportal.com

But don't waste your time, I doubt that any of them will work. Might be somethings to try if you're bored at a campground because nothing on the ride broke.

 

[systemdelete]

My radio shop I believe put a magnet in line on my power supply’s wires going to my LEDs from my lighting controller. Was getting a slight hum on a few channels we use around 800mhz, now silent with the lights running. Radios, Lights, and horn are all controlled by the controller so anything back-feeding RF into it needs to be stopped for driver sanity.

 

[Downs]

I'd bet running straight to the battery would help cut down on all or most of the issues with electronic noise.

 

[old_man]

Put a .001uf, .01uf, .1 uf, and 1.0uf ceramic caps as close to the lights as possible. Follow up with a ferrite before the wire back to the battery.

The reason for the 4 sizes in parallel is that the smaller caps have a higher frequency response. Each size basically will help across the whole band, but will be better at a portion of the frequency range, so by using the different sizes, you maximize the whole thing. These caps are dirt cheap. Remember, use the ceramic caps, not the old styles.

The problem comes from the fact that you have to limit the current through LEDs. In order to cut down power consumption, they have done away with a series resistor and put a cheap chopper circuit in its place. You may have noticed this problem driving on the interstate. Many big rigs run a ton of these cheap LEDs and as you go by them, you will hear a ton of static in your AM radio. What you may not know is that the interference can play havoc with your cell phone as well.

 

[TheGreyhound]

I'd bet running straight to the battery would help cut down on all or most of the issues with electronic noise.

It did nothing for me. I tried all combinations of a) lights and radios coming from fuse block, b) one or the other coming direct from battery, and c) both coming direct from battery.

The noise is over the air, not through the wires. Confirmed this by my handheld. Just bad luck on the LED aux lights. The LED headlights and turn signals do not generate the spurious RF though so its fine I guess.

 

[LostInThought]

I am having some added static/interference when fog lights are turned on. The fog run on the factory wiring harness but are diode dynamics brand lights. The radio power takes from a block under drivers seat that is supplied via 2awg direct from battery. The antenna is on rear hatch mount. Fogs are on lower front bumper. This is a yaesu ftm400 in a 2017 4runner. Has anyone ever experienced this? Any idea fir solution?

Hi Louisiana Overland!

I'm running VHF/UHF radios (ham and GMRS) in an '18 4Runner. Good news is that the vehicle platform is pretty EMI/RFI quiet. Also, I think your power wiring should be reasonably quiet - the block under the driver seat wouldn't be my first guess as a the source of the problem. Just off the top of my head, it sounds like the problem might be a cheap LED driver circuit in the lights. The physical separation suggests that problem might more likely be EMI "in" the power/ground rather than RFI that the other radio cabling is picking up as if they were antennas. Here's the sequence of things I'd try in chasing this down:

1. Ferrite beads on the power/ground for each light (nearer the light is better - stop the circuit EMI at the source)
2. Ferrite beads on the power/ground for the radio (nearer the radio - stop the circuit EMI where it enters the radio)
3. Ferrite beads on the mic/antenna cables at the radio (stop these cables from picking up RFI and carrying it to the radio like antennas)
4. If you have the remote head of the radio separated, use a shielded Cat6 cable with beads (again stop RFI traveling on this cable)

If one or more of these steps improve the situation but don't resolve the problem, you can try switching to toroid cores (see the pic) - more passes through the torus will provide more suppression. (The bead essentially permits one pass through the torus) Use a wire tie to support the weight of the core to protect the wiring from vibration.

If the beads aren't helping, you might be stuck with the interference until the lights are replaced.

The FTM400 and a lightbar/foglight set up are both on my wish list, so I'd be really interested in hearing what helps. Best of Luck.

 

[Graeman]

I have the same radio Yaesu FTM400 and I have 3 pairs of LED lights on my Jeep. The refi interference was so bad that turning on just 1 pair would knock out the radio. To combat the issue I installed ferrite chokes that clip onto the existing wires. I put them at the beginning of each light housing and then again at the end near the battery. I added them to the radio power supply, too. It helped quite a bit, but not enough. I then went on Amazon and bought some shielded 2 pair wiring and replaced all of the LED light wiring with it and that knocked all of the rfi interference out. I replaced the wires starting at the LED pods and ran them all the way to the light controller under the hood.

 

[TheGreyhound]

I have the same radio Yaesu FTM400 and I have 3 pairs of LED lights on my Jeep. The refi interference was so bad that turning on just 1 pair would knock out the radio. To combat the issue I installed ferrite chokes that clip onto the existing wires. I put them at the beginning of each light housing and then again at the end near the battery. I added them to the radio power supply, too. It helped quite a bit, but not enough. I then went on Amazon and bought some shielded 2 pair wiring and replaced all of the LED light wiring with it and that knocked all of the rfi interference out. I replaced the wires starting at the LED pods and ran them all the way to the light controller under the hood.

Yeah shielded wire definitely would help.... I guess the extra cost isn't worth it to the chinese LED manufacturers....

 

[Graeman]

Hi Louisiana Overland!

I'm running VHF/UHF radios (ham and GMRS) in an '18 4Runner. Good news is that the vehicle platform is pretty EMI/RFI quiet. Also, I think your power wiring should be reasonably quiet - the block under the driver seat wouldn't be my first guess as a the source of the problem. Just off the top of my head, it sounds like the problem might be a cheap LED driver circuit in the lights. The physical separation suggests that problem might more likely be EMI "in" the power/ground rather than RFI that the other radio cabling is picking up as if they were antennas. Here's the sequence of things I'd try in chasing this down:

1. Ferrite beads on the power/ground for each light (nearer the light is better - stop the circuit EMI at the source)
2. Ferrite beads on the power/ground for the radio (nearer the radio - stop the circuit EMI where it enters the radio)
3. Ferrite beads on the mic/antenna cables at the radio (stop these cables from picking up RFI and carrying it to the radio like antennas)
4. If you have the remote head of the radio separated, use a shielded Cat6 cable with beads (again stop RFI traveling on this cable)

If one or more of these steps improve the situation but don't resolve the problem, you can try switching to toroid cores (see the pic) - more passes through the torus will provide more suppression. (The bead essentially permits one pass through the torus) Use a wire tie to support the weight of the core to protect the wiring from vibration.

If the beads aren't helping, you might be stuck with the interference until the lights are replaced.

The FTM400 and a lightbar/foglight set up are both on my wish list, so I'd be really interested in hearing what helps. Best of Luck.

That is exactly what the issue was with me. I bought a 20 pack of ferrites from Amazon and put them just like you said. Worked for me on my Jeep JK. I am also changing out the wiring to the remote head to shielded wire once my new RJ9 4p4c terminal ends arrive.

 

[old_man]

That is exactly what the issue was with me. I bought a 20 pack of ferrites from Amazon and put them just like you said. Worked for me on my Jeep JK. I am also changing out the wiring to the remote head to shielded wire once my new RJ9 4p4c terminal ends arrive.

WARNING!!! Technical crap ahead
All ferrite chokes are not the same. The material and shape determines the frequency range. Some chokes are for very high frequency or very low frequency. As it turns out, the noise caused by the choppers is broad band. In other words it ranges from low to high frequency. If you remember from your electronics training.... chopping generates a square wave and a square wave is the sum of all the odd harmonics, some of which will fall in the frequency bands of interest. The key is to get rid of the square wave as close to the chopper as possible. This is done with a cap(s) across the power at the lights. As I discussed in previous posts, use higher quality ceramic caps and caps of a broad range of values. Caps have an intrinsic resonant frequency where the filtering is better/worse. This is due to the cap material and the parasitic inductances in the packaging. That is why you use multiple values.

 

[RoarinRow]

Some logical and technical solutions on this thread. I just installed a Ham radio in my rig, but haven't tested with my LED lights on. Will be keeping an eye out here for continued recommendations and solutions...

 

[LostInThought]

WARNING!!! Technical crap ahead
All ferrite chokes are not the same. The material and shape determines the frequency range. Some chokes are for very high frequency or very low frequency. As it turns out, the noise caused by the choppers is broad band. In other words it ranges from low to high frequency. If you remember from your electronics training.... chopping generates a square wave and a square wave is the sum of all the odd harmonics, some of which will fall in the frequency bands of interest. The key is to get rid of the square wave as close to the chopper as possible. This is done with a cap(s) across the power at the lights. As I discussed in previous posts, use higher quality ceramic caps and caps of a broad range of values. Caps have an intrinsic resonant frequency where the filtering is better/worse. This is due to the cap material and the parasitic inductances in the packaging. That is why you use multiple values.

A very good point on the ferrite chokes. If someone needs more detail on selection and use, the tutorial pages at Palomar Engineers are helpful:

Ferrite Chatter Noise - Palomar Engineers®

GOT DC Cable Chatter? Did you install snap on ferrite beads on each individual cable as shown below? If you did and your snap on beads are vibrating (or chattering like the wind up teeth shown to the left), then you need to rethink your installation! The dc current through the cable wound on...

palomar-engineers.com

Ferrite Mix Selection - Palomar Engineers®

Ferrite Mix Selection Guidelines Quite often we are asked which mix is best for a certain application or frequency range and there is a lot of misinformation on the internet and elsewhere regarding the selection of proper mix for a given application. Material Types There are two basic ferrite...

palomar-engineers.com

Ferrite Cross Reference - Palomar Engineers®

Construction articles in magazines and books often use part numbers of firms no longer in business or whose parts are hard to find. Many Palomar Engineers parts are identical or can be used as replacements. Use these tables to find substitutes. FERRITE TOROIDS Ferrite cross reference for Palomar...

palomar-engineers.com

Ferrite Ring Toroid Specs - Palomar Engineers®

Ferrite Toroid/Ring Cores are available in numerous sizes and mixes (permeabilities (µ)). Their permeability range is from 20 to more than 15,000. They are very useful for resonant circuit applications as well as wideband transformers (baluns/ununs) and they are also commonly used for RFI/EMI...

palomar-engineers.com

Palomar Engineers is very responsive and helpful, but you might also check the comments on ferrite cores from Amazon. Some like this one at Amazon have comments noting that they solved an LED headlight problem (just an observation, not an endorsement).

Old_Man's description of problem harmonics coming off a square wave generator is spot on. If I understand his suggestion correctly, it's a variation on a multistage DC L-Filter or DC Pi-Filter for EMI where the ferrite bead provides the inductance. There are a lot of variations available for purchase if someone didn't want to build one. You could start looking for "DC noise filters" on Gigaparts.com or Ham Radio Outlet but I'd hazard a guess that most of these are only single stage L-Filters and won't be as effective as Old_Man's circuit.

 

[M Rose]

A very good point on the ferrite chokes. If someone needs more detail on selection and use, the tutorial pages at Palomar Engineers are helpful:

Ferrite Chatter Noise - Palomar Engineers®

GOT DC Cable Chatter? Did you install snap on ferrite beads on each individual cable as shown below? If you did and your snap on beads are vibrating (or chattering like the wind up teeth shown to the left), then you need to rethink your installation! The dc current through the cable wound on...

palomar-engineers.com

Ferrite Mix Selection - Palomar Engineers®

Ferrite Mix Selection Guidelines Quite often we are asked which mix is best for a certain application or frequency range and there is a lot of misinformation on the internet and elsewhere regarding the selection of proper mix for a given application. Material Types There are two basic ferrite...

palomar-engineers.com

Ferrite Cross Reference - Palomar Engineers®

Construction articles in magazines and books often use part numbers of firms no longer in business or whose parts are hard to find. Many Palomar Engineers parts are identical or can be used as replacements. Use these tables to find substitutes. FERRITE TOROIDS Ferrite cross reference for Palomar...

palomar-engineers.com

Ferrite Ring Toroid Specs - Palomar Engineers®

Ferrite Toroid/Ring Cores are available in numerous sizes and mixes (permeabilities (µ)). Their permeability range is from 20 to more than 15,000. They are very useful for resonant circuit applications as well as wideband transformers (baluns/ununs) and they are also commonly used for RFI/EMI...

palomar-engineers.com

Palomar Engineers is very responsive and helpful, but you might also check the comments on ferrite cores from Amazon. Some like this one at Amazon have comments noting that they solved an LED headlight problem (just an observation, not an endorsement).

Old_Man's description of problem harmonics coming off a square wave generator is spot on. If I understand his suggestion correctly, it's a variation on a multistage DC L-Filter or DC Pi-Filter for EMI where the ferrite bead provides the inductance. There are a lot of variations available for purchase if someone didn't want to build one. You could start looking for "DC noise filters" on Gigaparts.com or Ham Radio Outlet but I'd hazard a guess that most of these are only single stage L-Filters and won't be as effective as Old_Man's circuit.

Also the prebuilt filters will be way more expensive than building the circuit your self...

 

[tacocart99]

I have another issue. Maybe you have an idea of how I can remedy it. Last night I was on a local net and my HT was not cutting it. So I got into the rig with the mobile in hopes that would reach out to them. Last nights net was simplex however the mobile did reach! When I was sitting just running off the truck battery the signal was clear as crystal. As soon as I turned the truck on and more specifically my LED headlights I could no longer hear the net. The RX was completely gone. I turned the lights off and I could hear them again. Any idea what is going on here? Would a ferrite choke fix this? Or from what this thread says if I switch back to halogen lights the problem will go away. It is like HAM black magic. If the LED headlights go on the radio signal goes off and as soon as the LED headlights go off the radio comes back on. The problem is I can not drive around town at night with no headlights. For obvious reasons. I also can't drive around town without a radio. I will try putting the OEM bulbs bac into the truck. Any suggestions are welcome.

 

[old_man]

A ferrite choke may help. The problem is that the lights run an active switching power supply to drop the 12v down and limit it to the roughly 3v the LEDs use. Actually they need a constant current, not constant voltage. These switchers do not have any inductance or capacitance to curb the RF emissions. If a choke does not do it, go to coax to feed the lights with a cap at the LEDs.