[SeaStar58]

A good number of LED's are coming in through offshore stores that ship LED products that were really not made to FCC standards and were never meant for distribution in this country which adds another wrinkle to things. Many who buy LED's factory direct from Asian or South American sources such as through EBay or Amazon could very well find that got something that will interfere with VHF, AIS, AM, FM, etc and even hard wired audio sources or computer devices powered by the electrical system on their boats.

It's become a growing problem since many people will only look at a price tag and don't consider whether the manufacturer of that bargain LED fixture the got shipped via China Mail, etc gave any thought to meeting regulations designed to prevent interference with radio or even hard wired audio or computer systems.

I remember some time ago the first smatterings of this were relevant to bargain Color Changing LED's that folks were putting on Pontoon and Deck Party boats that were interfering with the boats PA and Music Systems and later found out also caused problems with 2 way communications.

It can go beyond LED's too. In the GIS Skiff we had a sudden drop in accuracy from the Digitizer Boards and all sorts of issues with system lockups that drove us crazy until we asked if anyone had gotten any new devices that they were using in the work area. Someone had broken the power supply/charger for their MP3 player and bought a bargain replacement brick that did not have an FCC classification. Once we unplugged it all the issues went away and we were thankful that is was not a mass failure of a several hundred thousand dollars worth of specialized cartographic equipment. One could only imagine the potential errors some of these really bad/dirty devices could introduce to communication equipment, autopilots, depth sounders and nav stations.

Any new electronic accessory LED or not could cause interference with more than just radio communications if its poorly designed or not really made to be sold in the US or other countries with communication regulations regarding interference.

 

[SeaStar58]

Does proximity of the antenna and offending LED matter? Is there a distance that sub par LEDs have no impact?

So AIS is VHF and there is no acquisition time. You turn it on and all signals appear at targets.

Can one do a work around by turning the tricolor off and see signals appear and then back on again? Or is this simply blocking weaker distant signals?

The distance from the offending LED to your radio or antenna at which there is no impact is a tough one as the moderately offensive units may have a variable distance depending on how everything combined is setup on your boat while the totally off spec lights (and they could be the cockpit or cabin lights) can impact anything connected to your boats electrical system since besides RF interference they also can feed back into the 12 volt wiring. The really bad part of this is the horribly off spec ones can impact any digital device having the potential to make depth readings and nav data from electronic devices questionable even if they are not creating audible evidence of their interference.

In the case of the cartographers (digital map making) equipment loosing accuracy it was oscilloscope readings on the power coming into the equipment that caused us to go on the Witch Hunt for the offending device and there was no audible clue from any device creating audio in the area. We had to review all work done in that area back to the day the offending device was first plugged in. This had the potential to have cost us hundreds of thousands of dollars and possibly more especially if product had gone out and clients had suffered losses from it before we noticed the issue. Yes AC verses DC on a boat however power line interference can impact devices on both.

Yes shutting the lights off when your using you nav station, dept sounder, radio or AIS can stop the interference as long at the problematic lights do not have a power brick/digital controller that stays active even when the lights are not running.

There is no one cut and dry fits all answer from how this has been developing over the past year or so. Were the lights designed to meet FCC specs and slightly missed, way off FCC specs, not even meant to be sold in the US or just some cheapest of the cheap product (fakes made to look like name brands included here) where no real consideration aside from their lighting up the first few times you flipped the switch was given?

We could be looking at just the tip of an ice burg here.