[RFI] Dimmer Behavior

Dale svetanoff at earthlink.net
Fri Mar 11 00:27:45 EST 2022

Jim and All,
My house was built in 2000 and has several Lutron dimmers in it (all 3 bedrooms, living room, family room).  I have never had RFI from any of the dimmers, largely because I do not use any LED bulbs or fixtures.  All bulbs on dimmers are true incandescent.  The primary reason I am sensitive about having LED bulbs in the house is the fact that I am an active listener to AM broadcast.  For example, I listen to WBBM-AM in Chicago (780 kHz) when eating breakfast each day.  (I am in eastern Iowa and Chicago is about 170 air-miles from the AM stations there.)  I use an RCA (formerly GE) Super Radio II for the job (integral ferrite bar antenna and tuned RF front end for best sensitivity).  I tried some LED bulbs and they wiped out reception by that radio and others that were "hot" enough to pull in Chicago stations during daytime.
Most of my fixed (non-dimmable) lamp fixtures use CFLs or regular fluorescent tubes (I have 18 such tubes in my shack and workshop).  The CFLs save energy and do not cause me any RFI on the ham bands, but they are getting tough to find.  I buy mine from eBay or Amazon.  I do live on acreage with my HF antennas around 100 to 300 feet away from the house.  I doubt that LEDs would interfere with my ham antennas, but I will not tolerate RFI to the AM b'cast band.  (Note that the FCC is tying to "salvage" AM b'casting using a variety of "tricks" that are not likely to help.  They seem to ignore the mess they created when they allowed so many devices to emit too much garbage in the band.) 
Jim, my thanks to you for your never ending publishing of ways to reduce RFI and EMI.  However, when it comes to noise sources, we both know that the best cure is to eliminate or reduce the emissions from the source.
73, Dale
Retired EMC engineer   
-----Original Message-----
Sent: Mar 10, 2022 2:50 PM
Subject: Re: [RFI] Dimmer Behavior
On 3/10/2022 12:03 PM, Dan K2YWE wrote:
> I need a recommendation for a modern LED friendly dimmer that is known to
> be EMI-Free, I operate 160m-6m.
I've been using Lutron dimmers with FEIT- and Phillips-branded LED bulbs for a few years. Lutron has a pretty good reputation for being relatively free of RFI, but I can't testify to that for these dimmers and bulbs, because when they're in use, I'm not in the shack. :)
NA6O has done some pretty serious lab-testing of LED bulbs for RFI, and lists several FEIT products as clean.
73, Jim K9YC
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