[Public-List] Radio interference problems from marine LED lighting

[Paul Wilson]

I agree that ordinary DC-powered LED cabin and running lighting shouldn't
pose a problem. The multi-function masthead LED lights, however, contain
control circuitry that needs to be properly designed, shielded, and tested
for unintentional RF emissions. It's also possible that some LED assemblies
contain switching power supplies to allow them to operate on either 12- or
24-volt marine systems.

Paul, Slainte #129


On Wed, Aug 22, 2018 at 7:32 PM R Kirk via Public-List <
public-list at lists.alberg30.org> wrote:

>
> From an expert associate of mine [My translation = Live with it]:
>
>
>
> LED’s will run DC at the diode so are actually not the problem. The power
> supply (ballast, transformer, inverter/rectifier, etc)  would be a
> problem.  If boat power is DC then a good light would have a DC/DC which
> should not XMT at all.  A poor quality (bad design, mismatched, unshielded)
> power supply can cause issues.
>
> Now that being said, the VHF emitter could have a resonance with
> wiring/circuit board of the light causing feedback.  That could happen and
> it would be just bad luck on a particular combination of boat, antenna, and
> light.  If these are mounted on top of a flat base plane (like the cover of
> something), then the design, frequency and spacing would all come into play
> on interference.  This could happen to any combo of things.  Best solution
> would be to shield and ground the lamp to eliminate that, but that would
> take some RF design knowledge.
>
> I suspect the latter explanation would cause isolated and
> tough-to-reproduce issues hence the urban legend status.
>
>
>
>
>
>
> -----Original Message-----
> From: Michael Grosh via Public-List <public-list at lists.alberg30.org>
> To: Alberg 30 Public List -- open to all <public-list at lists.alberg30.org>
> Cc: Michael Grosh <dickdurk at gmail.com>
> Sent: Wed, Aug 22, 2018 8:07 am
> Subject: Re: [Public-List] Radio interference problems from marine LED
> lighting
>
> So the electromagnetic  expert engineer recommends try before you buy. Try
> what? How?
> Looks like to make that happen you have to  carry a vhf rig into the store,
> wire up the bulb you are interested in, and play with the squelch
> (mentioned further in the article).
> I'm not seeing that as a viable approach.
> Michael Grosh
> #220
>
> On Aug 21, 2018 9:44 PM, "Paul Wilson via Public-List" <
> public-list at lists.alberg30.org> wrote:
>
> An interesting piece from the American Radio Relay League, quoting the
> Coast Guard. I'd be a little concerned about the masthead LEDs adjacent to
> the VHF antenna.
>
> LED lighting (as with any electronic device) is supposed to be certified as
> "Part 15" compliant for spurious emissions, per FCC regulations.
> ----------
>
> http://www.arrl.org/news/us-coast-guard-warns-of-led-lighting-interference-to-marine-radios-ais-reception
>
> Paul (KI4PW) Slainte #129
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