Rigid LED light causing radio interference??

[lugueto]

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 back about the rigids making interference with his CB.

I've read about people in J**ps having trouble with A pillar mounted dually's and their FM stereo having interference

Anybody know the reason why this happens or how to solve it???

Cheers,

Luis

 

[cruiserlarry]

The reason is the driver boards in the Rigid lights do not have any type of electrical isolation, and they emit lots of spurious white noise, which is picked up by the antennas and transmitted through the sensitive receiver circuits of FM, ham, and CB radios.

You might be able to put filters on the power lines coming out of the lights, but more likely the Rigids are emitting the noise off the circuit boards, and not the inbound power.

I'd contact Rigid to see if they offer a solution...

 

[lugueto]

I will!!

I appreciate your reply!!

Luis

 

[Cabrito]

I use a DC Line Noise Filter on my vehicles.

This is the one I get from Power Werx

 

[DaveInDenver]

To be more specific it's the switched mode power supply inside the lights. You want to power LED arrays with a constant current driver to maximize their efficiency otherwise you create more heat than is necessary. There's at least a simple DC-DC converter in there I assume.

They are supposed to carry a FCC Part 15 certification against radiated noise and just so you know if anyone complains to the FCC about them it's up to the operator (you), not the manufacturer, to correct the issue.

If anyone know what these things look like inside it might not be difficult to filter them. Alternatively you could measure them for spectrum content and build notch filters to quiet them down.

 

[mpinco]

LED's are constant current devices vs. voltage devices. The low cost LED power supply is high frequency / high slew rate. A well designed LED driver circuit will maintain low emissions. Unfortunately I'm not sure there is a standard/certification for LED RF emissions today. There is analysis in-flight.

As for Rigid they are using low cost / cheap LED's with simple/high RF power supplies.

In fact this is becoming an issue on many fronts as people replace lights with low cost LEDs and then find remote controls no longer work, DAB services no longer work or other devices are interfered with.

In the end the manufacturer (Rigid in this case) needs to hear that they are selling product that emits high RF levels and that as people figure this out, their business model is at risk.


Edit add: Ask them if they are in compliance with EN 55015:2006, Amendment 2 ( http://www.cenelec.eu/dyn/www/f?p=104:110:2235354639749554::::FSP_PROJECT:23333 ) and see what they say......... LOL

 

[Crom]

I've seen the same complaint on Tacomaworld regarding the Rigids.

 

[DaveInDenver]

Edit add: Ask them if they are in compliance with EN 55015:2006, Amendment 2 ( http://www.cenelec.eu/dyn/www/f?p=104:110:2235354639749554::::FSP_PROJECT:23333 ) and see what they say......... LOL

I have no idea, it's entirely possible Conatel in Venezuela doesn't follow the FCC or CEPT guidelines for EMI/EMC. But since they sell Rigid lights here and in Europe I wonder if it's ever been tested or carries any sort of compliance documentation.

 

[cruiseroutfit]

Fwiw I don't get any intereference out of my ARB LED's (Rigid built) but I have gotten FM radio interference out of some different LED lights I had installed. I'm assuming it has to do with the proximately to the antenna?

 

[mpinco]

I have no idea, it's entirely possible Conatel in Venezuela doesn't follow the FCC or CEPT guidelines for EMI/EMC. But since they sell Rigid lights here and in Europe I wonder if it's ever been tested or carries any sort of compliance documentation.

I emailed Rigid asking them about RF emissions and CEPT. Let's see what they say. I suspect the regs and compliance are maturing/in-flight as this has become a growing issue.

 

[DaveInDenver]

Distance does help Kurt, but if you're getting interference and the light isn't right next to the antenna or feed line I'd bet those things would swamp your broadcast AM or someone's HF radio. They are switching in the tens or maybe a hundred KHz, so you're pretty far out on the harmonics. You could expect an LED or CFL to maybe be heard on 160m (which is 2 orders below FM broadcast) or 80m, but a few feet should be sufficient at VHF & UHF unless the designer has literally done nothing to control the transitions (which isn't uncommon any more).

They are switching a significant amount of current, so that they are noisy doesn't really surprise me if the designer just got done making a smart phone charger and uses the same practices with something several times more powerful. Thing is there's no reason that frequencies and edges on these things (or really any light) need to be so fast as to create any noise. It wouldn't take much effort to make them plenty efficient and still play nice with two-way radios. But no one cares as long it doesn't mess up cell phones and computers, which already have SMPS in them and more tolerant of radiation in these bands.

Has anyone tried grounding the case, assuming it's not electrically conductive to the power return (e.g. the negative wire)?

 

[lugueto]

Wow, I didn't expect this much feedback!!

As DaveinDenver said, in Venezuela there is nothing I can do, these sort of things are way too specific for anyone to research and ultimately there's no one to file a complain to, because the manufacturer is foreign. How do you know Venezuelan institutions and regulations, by the way???

Interesting that mpinco even sent those guys an email, I will be very interested to hear what they say..

I heard about RF chokes, will these help???

For now, I guess Ill have to adjust the squelch when I need the lights and turn them off when I need to cover longer distances on my radio?? A permanent solution would be great though..

Thanks!!

Luis

 

[DaveInDenver]

RF chokes might help. You'd have to put them on the CB and/or ham coax and power cables. You might have some success bypassing and choking the power to the LED lights, too.

Even here in the U.S. you could complain until you lose your voice, but it's probably not going to make any difference. The responsible party is the user, not the manufacturer. You could tell them you have chosen not to buy their product due to the interference and file a complaint with the regulatory board (the FCC here), but the best sure way is to impact their financial bottom line and make sure you let a lot of people know (ExPo, Facebook, you name it).

I'm familiar with the U.S. and Canadian bodies primarily because I design microelectronics here and generally have specs that require compliance to several groups. Also I'm a licensed amateur radio operator, so I'm also familiar with rules regulating what I am responsible for in radiating and being tolerant of as far as interference. I have to be aware not to cause interference but in some cases my ham license entitles me to a higher priority in disputes. The LED & CFL situation is actually a good one because if my neighbor has a light that is causing me interference above what our FCC Part 15 and Part 18 rules allow I am allowed to ask them to fix it with the authority of being a user of a licensed service. People who operate unlicensed devices generally are lower than licensed users and there is an order with the licensed services, sometimes I'm the primary user others I'm the secondary or tertiary.

My familiarity with European and some Asian rules is very basic from a couple of designs. It's far from in depth. I know next to zero about South America or Africa beyond what the FCC lists as equivalent bodies in other countries. If I ever had to design something destined for use I'd have to acquire the relevant standards and digest them.

 

[mpinco]

Typical electromagnetic emissions control require all panels and doors of equipment to be grounded and shut, creating a Faraday cage. Or .............. you design the product for low emissions. Or both.

We know where the LED/CFL industry stands .......... low cost / high slew rate / high emissions power supplies/drivers. Expecting consumers to begin complaining, in quantity, very soon. Plus the product return rate destroys someones business/cost model. Or both.

(kc0mab, EE, could solve Maxwell's equations in my sleep years ago, lately more software)

 

[4x4junkie]

The responsible party is the user, not the manufacturer.

Unless I'm mistaken, Part 15 requires products to not emit over a certain level of interference. Provided said product complies, then yes it falls upon the user to resolve the issue.
If a product DOES NOT comply however, then the manufacturer has some esplainin' to do (this is how I've always understood it anyway ).

I don't have experience with the Rigids, but have dealt with this on other types of LED lamps (Philips 10W LED MR16 12V lamps). The interference (wideband noise) generated by these lamps pretty much wipes out all radio reception from 10-250MHz when the lamp (or it's wire) is 20 feet from the receiving antenna, which to me seems far in excess of what the regulation should be. Of course I have no way to objectively test it though.
Oddly, the lamp had almost no effect on AM broadcast reception.

To deal with this, I lined the inside of the plastic lamp housing with conductive tape (tying it to the driver circuit's ground), added .01µF disc caps from each lead to ground, and wrapped the wire immediately where it exits the housing around a ferrite choke (being there was no room to put the choke inside of it). This cut the interference down by 20dB or so, but would still affect reception of very weak signals.
Since the Rigids already have metal housings, you wouldn't need to put foil tape inside them.

I have other similar LED lights that emit virtually zero interference (an occasional whistle on the AM BC band, literally zero on CB & VHF), which proves it's very possible to design a light that doesn't interfere with everything. It's unfortunate this isn't on most manufacturers radar it seems.

Interesting to know this about the Rigids too... I came real close to buying a set myself, but was turned off by the color of their light output.