Coast Guard Safety Alert: LED lights interfere with VHF & AIS radios

[RaymondR]

Originally Posted by Lake-Effect

Interesting thought. If one was to use an efficient switching DC regulator to regulate down to say 9v, then use that for LED nav lights that were designed to run on a guaranteed 9v... You would still need some form of current restriction in each LED assembly (eg a resistor to drop maybe 1 or 2 volts), but it would still be more efficient and you'd not have varying brightness thanks to the steady 9 v.


The two problems are:

1. system complexity - a separate regulated DC source for specific lights. What happens if the reg dies?
2. you still have a switching regulator, that needs to not radiate RFI

From the perspective of simplicity, the best solution overall is for the marine LED industry to just solve their RFI problems (as many already have)



Very interesting. Hmmm.

Just an observation that in this day and age the simplest oscillator is a programmed microcontroller. Tiny, cheaper, precision, no capacitors or ring counter required to do what you suggest.

(runs off to patent office )


OK I'm back. the problem here is that lighting a few identical LEDs sequentially will not produce more light than lighting just one of those LEDs continuously. Marine LED 'bulbs' have multiple LEDs because you want the sum of all the LEDs to produce the desired light level.

The requirement is to have a light of a certain colour visible at a certain distance.

Because of the way they are constructed LEDs tend to output a cone of light of an included angle. Consequently, to get full 360 degree coverage you need to use 12 each 30 degree output LEDs. If the one facing the observers eyeball switches on 16 time per second for a short period it appears to be a constant light. In contrast an incandescent bulb puts out a sphere of light most of which is wasted as it's only a small portion aimed at the observers eyeball. The LED aims the photons in a relatively narrow cone, the incandescent a wasteful sphere.

[tsenator]

Has anyone or anyplace compiled a list of masthead replacement LED lights that are "Low EMI" ? Specifically looking for tri-color / anchor Hella Marine light bulb replacements .



All I have gotten from this thread is that there might be an issue with your VHF receptions but you'll have to "test for yourself" . It would be great if someone had done this with the top replacement LED's

[nofacey]

Navigation LED that DOES cause AIS interference. Used in AquaSignal stacked masthead tricolour/anchor light, masthead VHF/AIS antennae on a splitter.

Sam Allen branded Navigation LED bulb out of Australia - package pics attached.
- was so happy finding this replacement for a weak/progressively failing led - very bright, plus appeared better contained, so hopefully longer lasting.

Unfortunately, I turned masthead on with AIS already displaying multiple vessel around us, and immediately lost all AIS vessels. Very repeatable.
Signals would return after a period, but were much more erratic & prone to dropping.

Great for masthead anchor light, not so much Tricolour.

[a64pilot]

Originally Posted by tsenator

Has anyone or anyplace compiled a list of masthead replacement LED lights that are "Low EMI" ? Specifically looking for tri-color / anchor Hella Marine light bulb replacements .



All I have gotten from this thread is that there might be an issue with your VHF receptions but you'll have to "test for yourself" . It would be great if someone had done this with the top replacement LED's

I’ve done quite a bit of EMI /EMC testing on aircraft, so I’m a little experienced with what interference looks like.
So far I have been able to detect none from any of my Marine Beam lights, and I have a boat full of them.
My Aqua Signal Tri color also hasn’t caused any issue that I am aware of.
I have some elcheapo led strip lights that need to be off when using the HF radio though, they are noisy. I don’t use them anymore and ought to remove them.

I think so long as you stay with a quality manufactured LED complete light, or buy bulbs from a known good vendor that states in writing that their LED’s and power supplies have been tested for EMI you should be good.
I believe you get into trouble buying from a Chandlier and even West Marine sells a brand that has been shown to be problematic.
Many are I believe inexpensive sources LED’s repackaged and sold.
I think there are very few actual manufacturers, Hella, Aqua Signal and the big boys probably, but then I don’t believe they sell bulb conversions either.
None of my lights are conversions, I certainly understand the draw though they are a very small fraction of the cost of new complete lights.

[a64pilot]

Originally Posted by tsenator

Has anyone or anyplace compiled a list of masthead replacement LED lights that are "Low EMI" ? Specifically looking for tri-color / anchor Hella Marine light bulb replacements .



All I have gotten from this thread is that there might be an issue with your VHF receptions but you'll have to "test for yourself" . It would be great if someone had done this with the top replacement LED's

Only bulb replacements that I know are good are Marine Beam, as they make that claim in writing.
https://store.marinebeam.com/controlling-emi-1/

[Capt Phil]

In a similar but related vein...
A good friend purchased a Hans Christian sailboat several years back and the seller swore everything worked except the autopilot.
Through an abundance of caution, he talked the seller into accompanying him from Morro Bay to San Diego on a shakedown cruise. Sure enough, everything worked fine except the autopilot which had been profesionally installed in Morro Bay causing them to steer the whole wa!
After sailing without an autopilot for several months he asked me to have a look at it.
I found that the installer had mounted the gyrocompass behind the VHH but had coiled up the excess wire and taped to the bottom of the radio.
I took the excess wire and duck taped the compass amid ships in the bilge just forward of the engine in a separate compartment. The autopilot performed perfectly!
The new owner thought I was an electronic wizard... I didn’t mention that I had read about a similar problem in Practical Sailor just a couple of weeks before!
Phil

[joehersey]

The LED navigation light VHF interference problem is exacerbated by the lack of any existing EMC standards that could address the problem. The best available standard is IEC 60945, but that standard was designed to protect VHF radios and AIS from interferers separated at least 15 meters way from VHF antennas! Keeping navigation lights 15m from antennas is not very practical.

The Radio Technical Commission for Maritime Services (RTCM) has therefore established a special committee to develop an appropriate standard. See https://www.rtcm.org/committees. RTCM SC137 Electromagnetic Compatibility Requirements for LED Devices and other Unintentional Emitters Located Near Shipboard Antennas. Unfortunately it'll be about a year before one can be completed.

[john61ct]

that's optimistic

[john61ct]

EN 55015 ?

https://apps.fcc.gov/kdb/GetAttachme...g_number=20518

[Dsanduril]

Anybody have direct experience with the new (2019) LunaSea tricolor? We have the previous version that was specifically advertised to cause "no EMI" and it wreaked havoc with our AIS reception. Just curious if they have really worked out the bugs or if it is more advertising hype. They're not cheap and we had hoped the last one would be the solution but sadly it wasn't.

[joehersey]

Originally Posted by john61ct

EN 55015 ?

EN 55015 is a European EMC standard applicable to lighting, including LEDs. Its radiated emission limit at VHF is 40 dB uV/m at 3m, the same as that mandated by CISPR 15, the international IEC standard also applicable to lighting. In order to protect a VHF marine radio or AIS, you would need to separate an EN 55015-compliant LED ~103 meters from VHF antennas. Not very practical unless you have a very big boat.

IEC 60945 is better, with its 24 dB uV/m at 3m RE limit, requiring only 15m separation between a 60945-compliant LED and VHF antennas. While that standard is compliant with the SOLAS convention, which requires stuff on the bridge of a big ship be tested for EMC, that too won't help the navigation light problem very much.

CISPR 25, intended for the automotive industry which also has experienced LED interference, is the best yet, with a VHF RE limit at 22 dB uV/m at 1m. That should allow a CISPR 25-compliant LED to be as close as ~2.5 to 4m to VHF antennas before interference is caused.

RTCM hopes to do better than that by bringing the required separation distance down to ~1m. But until that can be done, if you can find a CISPR 25 Class 5-compliant LED, buy that. Its the best widely-recognized international LED EMC standard we could find.

[a64pilot]

Originally Posted by Dsanduril

Anybody have direct experience with the new (2019) LunaSea tricolor? We have the previous version that was specifically advertised to cause "no EMI" and it wreaked havoc with our AIS reception. Just curious if they have really worked out the bugs or if it is more advertising hype. They're not cheap and we had hoped the last one would be the solution but sadly it wasn't.

I’m suspect of the zero claim, that’s just not possible. It may be undetectable with ordinary equipment, but that’s not zero.
This is I’m sure marketing making that claim, why Engineering is upset with marketing, but the Boss listens to marketing.

However surely it’s a very, very low emf field for them to make that claim.
But you know, for that kind of money, it ought to be perfect

[Nicholson58]

Marine Beam has an Aqua Signal Tricolor replacement

https://store.marinebeam.com/aqua-si...lacement-bulb/

We too have dozens of their PWM regulated LED replacements. Marine Beam was aware of and addressing RF interference years ago. We have no trouble with their replacements.

I have had trouble with all We$t marine replacement LEDs we tried. Short life was my biggest beef.

[Simi 60]

I found a Panbo article talking about this and one of the bulb companies mentioned was this one in Australia selling $10 bulbs.
https://www.ledshoponline.com.au/pro...hop-australia/

I sent an inquiry and here's the response

We now make dedicated BAY15D 24v bulbs using resistors for current control.
No singing with these.
https://www.ledshoponline.com.au/pro...hop-australia/

RF has been a nightmare !

Its odd for us, I do the VHF test and get no sign of signal degradation when I turn the masthead on.
Turn masthead on with AIS and AIS gets wiped

[svmobert]

Originally Posted by Simi 60

Its odd for us, I do the VHF test and get no sign of signal degradation when I turn the masthead on.
Turn masthead on with AIS and AIS gets wiped

AIS is far lower power compared with a VHF radio and will be impacted earlier.