Re: LED Light QRM to TV reception
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Jerry,
Just curious, which inverter do you have?
The entertainment system is interesting,? is there a switching power supply associated with it ? A wall wart perhaps?? 73,
Gary/w0gx
On Tue, Jul 31, 2018, 11:33 AM Jerry Crawford via Groups.Io <K7UPJ= [email protected]> wrote: Gary, RFI is reduced when I turn off the charger and big ferrites on the inverter cables don¡¯t do anything.? There are also other sources of RFI, surprisingly such as from the entertainment system.
73, Jerry
Jerry,
Have you isolated your RFI to the coach inverter? 73,
Gary/w0gx On Tue, Jul 31, 2018, 9:01 AM Jerry Crawford via Groups.Io <K7UPJ= [email protected]> wrote: Steve,? Do you want to do a test with my new ANC-4 noise canceller?
I have lots of ferrites without much help.? Jerry On Jul 30, 2018, at 10:58 AM, Kevan Nason < knason00@...> wrote: Hi Steve. Hope you've been enjoying that camper this year.
Didn't answer right away because I've avoided LED lights to avoid RFI so don't have practical experience. Thought maybe someone else would speak up. But I've been reading whenever I run across talk about RFI and LED lights because I know I'll eventually to have to deal with it.
This web page seemed to sum up things I've read pretty well:
Interference seems to mainly come from the power supply. Power supplies for dimmable LED lights have been a particular issue. Ferrite is suggested on each side of the supply. Hams have said they have had good luck using 31 mix ferrite cores.?Another suggestion from some has been to replace the power supply and go?from a PWM to a linear type if you can. I haven't done any research on how to do that. I did note in passing that the above link talks about Phillips having a replacement "transformer" that might work if you want to explore that.
Hams have been sharing info on what bulb manufacturers have had low and high interference for a couple/few years. Maybe spend some internet time seeking out those reports and see if you can substitute some good ones for what you have. I've seen that type of discussion on several web sites.
As to FCC approval, there has been some talk about people getting approval and then downgrading the supply without getting re-certification. A board having good EMI protection is approved and then once it hits production the EMI suppressing components aren't installed. The holes are still there in the circuit board for the parts -- just that in order to save money for the manufacturer only those parts needed to make the lights turn on are installed. The EMI stuff isn't needed for that so they leave them out. There has been documentation of that actually happening. So far the FCC hasn't been pushing very hard for the manufacturers to do the right thing.
Kevan N4XL
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