Led interference

[jambo]

Copied from another forum thought it interesting.
[emoji3544][emoji3544] MARINE SAFETY ALERT FROM AMSA [emoji3544][emoji3544]

LED lighting found to interfere with VHF-FM radio and AIS reception

The U.S. Coast Guard has sounded the alarm over the potential for light-emitting diode (LED) lighting on vessels to compromise reception on VHF frequencies used for radiotelephone, Digital Selective Calling (DSC) and Automatic Identification System (AIS).

The distance at which the LED lighting starts to have an impact and whether the issue is limited to certain makes of lighting or navigation equipment, is unknown.

The U.S. Coast Guard has asked the U.S. marine industry to provide more detail of known incidents.

Due to their energy-saving capability and longer service life, LED lights are commonly used for navigation lighting, searchlights and floodlights, as well as interior and exterior lighting— including those used for visual effect.
The U.S. Coast Guard said that in one case, radio-frequency interference caused by LED lighting created a hazard that led to a serious safety incident.

‘The maritime rescue coordination centre in a United States port was unable to contact a ship that was involved in a traffic-separation-scheme incident by VHF radio. That ship also experienced very poor AIS reception.

‘Other ships have also experienced degradation of their VHF receivers (including AIS), caused by their LED navigation lights. LED lighting installed near VHF antennas has also been found to reduce reception.’

Strong radio interference from LED sources may not be immediately apparent to marine radio users, but there is a way to test for LED interference.

How to test for LED interference;

1. Turn off your LED light
2. Tune your VHF radio to a quiet channel, such as Channel 73
3. Adjust your VHF radio’s squelch control until the radio outputs audio noise
4. Re-adjust the squelch control until the audio noise is quiet—just slightly above the noise threshold
5. Turn your LED light back on
6. If the radio starts crackling when you turn on the LED lights, it is likely that the LED lights are affecting both your on-board VHF marine radio and AIS reception.

If you have experienced LED-lighting interference on your vessel, please report it to AMSA

Has this happened on your boat? Help us learn more, so we can address the issue.

Tell us:
• make and model of LED lighting
• radios effected
• distance from lighting to antennas and radios
affected;
and
• any other information that may help us to understand
the nature of the problem.
Send an email: reports@amsa.gov.au

[Pikey Dave]

Originally Posted by jambo

Copied from another forum thought it interesting.
[emoji3544][emoji3544] MARINE SAFETY ALERT FROM AMSA [emoji3544][emoji3544]

LED lighting found to interfere with VHF-FM radio and AIS reception

The U.S. Coast Guard has sounded the alarm over the potential for light-emitting diode (LED) lighting on vessels to compromise reception on VHF frequencies used for radiotelephone, Digital Selective Calling (DSC) and Automatic Identification System (AIS).

The distance at which the LED lighting starts to have an impact and whether the issue is limited to certain makes of lighting or navigation equipment, is unknown.

The U.S. Coast Guard has asked the U.S. marine industry to provide more detail of known incidents.

Due to their energy-saving capability and longer service life, LED lights are commonly used for navigation lighting, searchlights and floodlights, as well as interior and exterior lighting— including those used for visual effect.
The U.S. Coast Guard said that in one case, radio-frequency interference caused by LED lighting created a hazard that led to a serious safety incident.

‘The maritime rescue coordination centre in a United States port was unable to contact a ship that was involved in a traffic-separation-scheme incident by VHF radio. That ship also experienced very poor AIS reception.

‘Other ships have also experienced degradation of their VHF receivers (including AIS), caused by their LED navigation lights. LED lighting installed near VHF antennas has also been found to reduce reception.’

Strong radio interference from LED sources may not be immediately apparent to marine radio users, but there is a way to test for LED interference.

How to test for LED interference;

1. Turn off your LED light
2. Tune your VHF radio to a quiet channel, such as Channel 73
3. Adjust your VHF radio’s squelch control until the radio outputs audio noise
4. Re-adjust the squelch control until the audio noise is quiet—just slightly above the noise threshold
5. Turn your LED light back on
6. If the radio starts crackling when you turn on the LED lights, it is likely that the LED lights are affecting both your on-board VHF marine radio and AIS reception.

If you have experienced LED-lighting interference on your vessel, please report it to AMSA

Has this happened on your boat? Help us learn more, so we can address the issue.

Tell us:
• make and model of LED lighting
• radios effected
• distance from lighting to antennas and radios
affected;
and
• any other information that may help us to understand
the nature of the problem.
Send an email: reports@amsa.gov.au

It’s well known in certain circles that LED bulbs in cars & vans can interfere with DAB & FM reception. Another culprit is USB charger plugs in cigarette lighter sockets.

[Simonh66]

It will be the cheaper end of the market that cause these issues

[Salty John]

It's not necessarily the cheaper LEDs that cause the problem. The interference comes from the buck regulator that controls the voltage in the LED. Some versions oscillate at a frequency that messes with VHF transmission. (Very cheap LEDs tend not to use buck regulators, but they're not suitable for nav lights anyway).
It has been a problem on yachts for years because often the masthead antenna is alongside an LED navigation light. Even if the light is declared in compliance with RF emissions to CE standard it can still interfere with radio transmission. Some people report a complete blackout of AIS transmission as soon as they turn on their nav lights!
Make sure your nav lights guarantee they don't interfere with VHF transmission before you fit them.

[Simonh66]

Originally Posted by Salty John

It's not necessarily the cheaper LEDs that cause the problem. The interference comes from the buck regulator that controls the voltage in the LED. Some versions oscillate at a frequency that messes with VHF transmission. (Very cheap LEDs tend not to use buck regulators, but they're not suitable for nav lights anyway).
It has been a problem on yachts for years because often the masthead antenna is alongside an LED navigation light. Even if the light is declared in compliance with RF emissions to CE standard it can still interfere with radio transmission. Some people report a complete blackout of AIS transmission as soon as they turn on their nav lights!
Make sure your nav lights guarantee they don't interfere with VHF transmission before you fit them.

I didn’t say it was the chips that caused the issue

[lakelandterrier]

Or don't use LEDs for your nav lights

[simonl]

LEDs need to have the current limited, or they go pop. This can be done with a resistor in series, which wastes heat, or by using a chip that switches it on and off (modulates) very quickly. It's the rapid switching that causes interference.
I would take a slightly different approach to test it - simply turn the squelsh right down & if you can hear a change when you turn on your nav lights then they are interfering. It's viable to retrofit existing nav lights to stop them interfering.

[GuyC]

As I'm fitting Hella LED nav lights to my ongoing RIB project, I thought I'd ask Hella the question and I received the following response.

There was a third article about FLIR but it is over 600kB so I can't upload it.

[Fenlander]

Thanks for the info Jambo. Wondered about my Odeo LED "flare" and Unilite emergency torch.

Just tested and both didn't interfere thankfully.

[jambo]

Originally Posted by Fenlander

Thanks for the info Jambo. Wondered about my Odeo LED "flare" and Unilite emergency torch.



Just tested and both didn't interfere thankfully.

No problem glad to be of service [emoji106]

[Pikey Dave]

Originally Posted by GuyC

As I'm fitting Hella LED nav lights to my ongoing RIB project, I thought I'd ask Hella the question and I received the following response.

There was a third article about FLIR but it is over 600kB so I can't upload it.

I have Hella LED Nav lights & haven’t noticed any problems[emoji106]