It's the tiny onboard power supply, not the LEDs, radiating noise
I'll throw this up until a more skilled EE type chimes in.
The radiated noise causing interference is coming from the (poorly designed or poorly shielded) little internal DC-DC circuit on or in the light assembly, not the LED's themselves. To fix a "noisy" light, you would need to construct a little shielded box around that part of the light assembly.
That tiny power supply mounted in the assembly takes the input DC voltage, converts it to a high frequency, passes it through a small transformer, and converts it back to a different DC voltage before passing it over to the LED's themselves. Lots of ways for high frequency noise to "leak" if not designed and/or suppressed correctly, the real difference between "good" and "noisy" lights. Something Marine Beam has figured out that others have not.
Those plain ~16' LED strip lights on spools arrange their LED's in parallel groups of 3 with a series resistor to work straight from a nominal 12V source without needing an internal converter so therefore shouldn't radiate at all.
I do use a couple of series diodes in the power feed to those strips to drop my house voltage down so my battery charger doesn't shorten the life of the LED/resistor groups when it's charging. The 3 LED/resistor groups don't start to draw current until they see ~8V and then draw relatively proportionately with voltage after that, so having them on while battery charging at 13.5-14V (~6V above turn on) is driving them 50% harder than at a nominal 12V (4V above turn on).
--Mike
