[ETS/PARC List] LED lamps causing RFI problem

[Victor Pennetta]

The following message was forwarded by another member of the Amateur Radio Club of the National Electronics Museum - I think you'll find it interesting.



A couple of weeks ago I posted a message on the reflector about 2 meter RFI
that completely rendered the 2 meter spectrum unusable. While I got a few
suggestions about common sources, this was something completely new to me at
least.

At last the source of the RFI has finally been positively identified!

To recap, the wideband RFI centered on 145 MHz which began in mid-December
was isolated to a specific house in Caldwell, NJ about 700
feet from my home. The RF level was about 20db over S-9, or nearly 1
millivolt, yes, "millivolt', at my receiver. It wiped out the entire 2 meter
band as well as the lower portion of the public safety and aircraft
spectrum.

While the RFI sounded like AC line buzz, looking at it on a spectrum
analyzer showed a 20 MHz wide signal that swept and pulsated. PSEG (the local electric provider) was
instrumental in first identifying that the RFI was wideband and close to the
residence in question as I had determined from walking the area. I then used
a 4 element, 2 meter yagi to positively identify the direction of the source.
I considered that the problem might be channel 18 leakage from Comcast cable,
but that did not prove to be the case.

I was able to talk to the home owner who was very cooperative in working
with me to find the source. I first thought that it was associated with TV
usage but several tests did not yield the precise problem though the
Comacast cable box and Samsung large screen TV were able to be heard inside
the house on my Yaesu HT in AM mode but nowhere near the level I was seeing
at times at my home. It seemed that when the homeowner was not home the RFI
would disappear and in that case TV's were off.

Today, another test was made where the homeowner turned off all TV's and the
RFI was still present. She then started tripping breakers and the RFI
completely disappeared! It was now positive that the RFI was from something
In the home. Further testing revealed the source as 9 LED lamps in the
kitchen that had been installed in mid-December, at the time I first noticed
the beginning of the problem.

The lamps were obtained at Home Depot, and are the Eco-Smart brand, MR-16
halogen replacements, and are rated at 50w = 8 watts consumption. Obviously
this is going to become a really big problem, not only for PSEG as people
bite the bullet and purchase these things, but it will also become a FCC
issue as well, as they clearly exceed any radiated emission spec's for
consumer devices.

For now, since we know the source of the problem, I am working out with the
homeowner a plan to perhaps go back to the halogen lamps. This problem needs
to be escalated to Home Depot, the FCC, and anybody else that should be
notified before the entire 2 meter spectrum is lost to licensed users in
this country and others.

So, if you are thinking about LED replacements as was I, it might not be the
best thing to do or if you do, make sure you can return them or take up some
other hobby!

73, Roger, NJ2R