The February and April 2012 issues of RadCom (Radio Society of Great Britain's
monthly publication) treat the matter of interference from LED lighting. A 4W
LED spotlight, with three series-connected LED bulbs, powered by a miniature
switch-mode power supply that supplies 9.2 vdc from the 240 vac mains, caused
plenty of interference. The only filtering used was a 100uH series inductor on
the mains side of the power supply. No shunt capacitors were used.
Deutscher Amateur Radio Club has posted YouTube videos (DARCHAMRADIO being the
YouTube user name) about RFI from LED lamps. One of these by DL9KCE is in
English, and it is a worthy 14-minute presentation. Go to:
www.youtube.com/watch?v=o8zMhjXcmoA
73,
Charles, W2SH
> Date: Thu, 5 Apr 2012 18:07:48 -0700
> From: j_fitton@yahoo.com
> To: aa7jv@atlanticbb.net; topband@contesting.com
> Subject: Re: Topband: Home Depot LED bulb interference.
>
> Hi George,
>
> I first noticed the problem as a hiss on my favorite FM radio station.
>
>
> Tod, K0TO had a very good thought, that it may be the dimmable feature.
>
> To answer your question George, : Yes... Marked Clearly on the box.
>
>
> >I am wondering the if the LED
> >bulbs bought from Home Depot meet FCC Part 15 specs. Were
> >they marked so?
>
> >George, AA7JV
>
> jim / W1FMR
>
>
> --- On Thu, 4/5/12, GeorgeWallner <aa7jv@atlanticbb.net> wrote:
>
>
> From: GeorgeWallner <aa7jv@atlanticbb.net>
> Subject: Re: Topband: Home Depot LED bulb interference.
> To: "TOPBAND" <TOPBAND@CONTESTING.COM>
> Date: Thursday, April 5, 2012, 7:10 PM
>
>
> On Thu, 5 Apr 2012 16:01:12 -0400
> "Mike Greenway" <K4PI@BELLSOUTH.NET> wrote:
> > I wondered how long it would take before they started
> >selling some RFI
> > generating lighting. Soon we can have a complete
> >neighborhood of RFI
>
> I have tested compact fluorescent bulbs a couple of years
> ago and found that they were noisy. I have not tried to
> quantify the level of noise emitted, but it was about S5
> on my K3 at a distance of about 4 feet using a one foot
> wire for antenna. I have stayed with incandescent, but my
> neighbor has installed over 50 of them on his house. The
> noise coming from that direction (NW) is significantly
> stronger than what I get from any other direction. Since
> he has installed the CF (and many LED) bulbs, I have not
> made one JA QSO! Fortunately, my DHDL, which looks towards
> EU (NE) completely blocks the noise and I am still able to
> work Europe.
>
> On the other hand, I have LED lights installed on my dock,
> which is only about 20 feet to the East of the RX antenna,
> but these LED lights are driven by well filtered drivers
> in metal boxes. No noise from these lights can be
> detected.
>
> It seems to me that we have a very serious threat from
> noisy "switched" light sources (and other digital noise
> generators, like Variable Frequency Drives) that have not
> been properly filtered. I am wondering the if the LED
> bulbs bought from Home Depot meet FCC Part 15 specs. Were
> they marked so?
>
> George, AA7JV
>
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
_______________________________________________
UR RST IS ... ... ..9 QSB QSB - hw? BK
|