i would tend to think the LED power supply, usually a switching buck-converter, would be the cause. blaming the LED is like if water dribbles from the end of a garden hose, so you blame the hose, rather than the leaky valve.
just my thoughts...
Yep, LEDs are DC.
Some switching power supplies can be and are very noisy.
They cram those inverters into the base of the bulbs. Size and costs over filtering.
I'm sure many of them only do the least amount of filtering necessary to satisfy the FCC rules, and probably many miss the mark and make it to market anyway.
The LEDs on our bikes may not have inverters since we're dealing with DC to start with, but high output and LED are not typically synonymous, so there's some boosting and cooling electronics in the headlight bulbs.
Take any old AM radio ( if you can find one) walk around your bike with the engine running and the lights on, see if it interferes with reception on the radio.
Whew! Where's the coffee?
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