I know nothing about RFI, so maybe it's not strange.I have my MH inside my shop building. It is plugged into a 110v outlet. Plugged into the same outlet is a boom box radio.When I turn on certain (OEM) 12v LED light fixtures in the RV, I get RFI on AM radio on the boom box out in the shop. Even with the breaker in the RV for the PD converter switched off! So, converter off, but other 110v circuits in the RV would have power available. Nothing running on them, but they have power available. Fridge is off, everything 110v is off. If I unplug the RV from the shop wall, the RFI goes away, even while leaving the LED lights on in the RV.I'm not sure if this happened with the previous converter in place, the WFCO.The PD is grounded to the chassis per instructions. Also, I just installed a Morningstar SureSine inverter. It is set to be always on when the battery switch is on. I could change the DIP switch for that and see what happens. Nothing was running off the inverter, though.I tried to test the RV radio but inside the metal shop building, unlike the boom box, it won't receive diddly squat on AM. Explain the RFI please?

I would start by verifying the connection to the rig. make sure the ground in the shore power cord is good.Make sure the receptacle is grounded properly that you are plugging into.I am guessing you are using an adapter to go from a 30 amp RV cord body to a 15/20 receptacle.

It's not the converter, it's the LED itself. A majority of 12V LED's have switching regulators in them to maintain a constant output even with a fluctuating input. Unless properly filtered on both in and outputs, those switchers can cause complete havoc from the AM band to well over 2GHz. I have seen them take out DSS but never looked at where it was happening...Anyway, there are only a few manufacturers that have paid attention to RFI filtering, Starlights being one in the past few years, but it can be a big problem in campgrounds.

Two types of RFIRadiated...transmitted thru airConducted...transmitted via hard wireEven though you have opened the CB for converter that only cuts connection on hot wire.......does nothing to common wire. Until you unplug RV power cord then all physical connection is cut and no more interference.So that LED light is inducing RFI via conducted method.Just curious...Is this LED light a fluorescent conversion?

Sometimes your house connection is not up to par. Perhaps the GROUND at the house receptacle is bad...Must have all three connections BLACK-WHITE-GREEN made betwen the trailer and the house though all of the adapters you might be using...To be absolute sure all is OK use one of these TEST adapters...Make sure the bottom three lights work as shown on the label for CORRECT...You can also use this pictorial for proper AC VOLTAGE readings using a MULTIMETER. It must read exactly as shown in the pictorial...Roy Ken

There's nothing wrong with anything. The LED lights are RFI generators. Your cord is acting as the conductor. Breakers don't disconnect all the wires, just the hot ones.

Strange radio interference situation | Good Sam Community

wa8yxm
Explorer III
Dec 07, 2014
It is called common mode interference, The power line is common to both the radio and the RV, which is why when you unplug the RV it goes away.

LED lights, by their nature are noise generators (Ideally it is WHITE noise, and WHITE light) they can be filtered to reduce it but total elimination is not easy.

RV Florescent lights have an electronic device we call a ballast but it is really an inverter, Usually MSW (Since the lights do not care) but nearby radios may be affected by those as well.
Snowman9000
Explorer
Dec 07, 2014
Thanks all.
Someone asked if they were conversions lights. No, they are OEM-installed fancy pants LED fixtures. I wonder if my previous RVs with their ebay 921 base LEDs did the same.
RoyB
Explorer II
Dec 07, 2014
Any LED light that has a BUILT-IN BUCK BOOST REGULATOR CHIP is prone to give off RFI signals.. Doesn't matter where they are high dollar or el-cheapo or which company sells them...

They meet FCC regulations and if you read the fine print they say they may cause interference...

I replaced all of mine in 2010 I think it was for the EBAY/CHINA $4.99 NON-REGULATED 12VDC-14VDC LED boards and bought a bunch of spares which I haven't used yet.

Mine are good and bright and will start loosing 3-leds in a segment as they age out. Figured when they got too dim to use I would just replace them with a new $4.99 LED board. I have a few 3-segment off now but still bright to use.

Roy Ken
SCVJeff
Explorer
Dec 08, 2014
I'll bet that 90% of the LED's out there have no cents.
wa8yxm
Explorer III
Dec 08, 2014
I will say again that an LED is the very defination of a noise generator. They work by making Noise in the visible light spectrum, but they also make noise all over the EM Map, from audio all the way to visible light. including all Radio bands and frequencies. Some light fixtures are well filtered to prevent this, others not.

Someone ask about the E-BAY 921 LED replacements.

I have E-bay 1141 LED replacements and they put out a lot of NOISE on th 2 meter ham band, well some of them do, (Actually the worst ones were the expensive ones I got at the dealer, not the EBAY units)

IF it ever gets to the point where it truly bothers me I'll filter them.
SCVJeff
Explorer
Dec 08, 2014
Let's be clear for the non-technicals.... It is NOT the LED itself that is the major contributor, it is the switching regulator. Those LED's that no not contain regulators are not the problem.
ken_white
Explorer
Dec 08, 2014
SCVJeff wrote:
Let's be clear for the non-technicals.... It is NOT the LED itself that is the major contributor, it is the switching regulator. Those LED's that no not contain regulators are not the problem.

Correct, the cheap LED's that use resistors to limit their current do not generate EMI or RFI.

Switching regulators generate numerous harmonic frequencies related to the switching frequency due to the square-wave shape and is determined by using the Fourier Series.

I use cheap LED's for this very reason.
Snowman9000
Explorer
Jan 23, 2015
As an update on this, the offending light fixture also scrambles a digital OTA TV signal on the RV's 12v TV. Whether it is affecting the TV itself, or the antenna signal, or the amplifier, I dunno.

Edit: it also affects the in dash radio.
MEXICOWANDERER
Explorer
Jan 23, 2015
This is sort of above my pay grade but with my army ants number of LED fixtures I am having significant luck with the following between the switch and LED load.
Canadian_Rainbi
Explorer
Jan 24, 2015
Wayne Dohnal wrote:
Someone still listens to AM radio?
I judge what I listen to by the content of its programming, not the wavelength of its signal.

AM is Amplitude Modulation. It has nothing to do with frequency (Aircraft still use AM in the VHF band)

Since RFI is essentially Amplitude Modulated it's hell on AM Radios. IT may be conducted (power cord--un plug, don't just kill the breaker) or radiated. If radiated, you are likely just out of luck. Or turn the lights off. I had to take take the LEDs out and go back to incandescent in my ham radio room.

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