LEDs don't generate noise themselves, the circuits added to manage volts and amps for brightnesses and LED life do. In bulbs, you can't get to these without destroying the bulb. In LED "units" messing with the circuits will void the warranty.
Remove the
vhf antenna and listen to the
vhf. If you still have the noise the LED bulb/unit is putting a noise signal into the supply side for the radio and you need a filter on the radio power red/white. You can get these from a car stereo shop. A second way th verify this is move the mast-head bulb to a deck level bulb socket and check for noise.
Second, borrow a VHF
handheld if you don't have one. Turn the light on and go to the mast head (with your main VHF OFF). Move the handled around the light and see if you get the noise. If you can raise the
handheld high enough to escape the noise, raise your installed antenna. Most antennas have extension struts you can buy.
I'd still put a noise filter across the radio DC supply
lines in any case.
One note, commercial operators with wheelhouses high off the water here on the East Coast don't like the mast-head tricolors. They make it very hard to figure out how far away a boat using one is. If two boats are side by side, one using side
lights and one using tricolor, the tri-color boat will appear to be a larger vessel with brighter
lights farther away. Offshore it's a different story.
