I've been dealing with VHF/AIS
interference with an Aqua Signal LED tricolor. If fails a simple test--turn the
VHF squelch down on a seldom used channel until you get
noise, then turn it up till the
noise just goes away. Then turn on the tricolor--the radiated noise from the AS fixture breaks the squelch every time, and goes off when you turn the tricolor off.
Aqua's response is to blame everything except their 'tested and certified' light fixture. Their competitor LunaSea, has acknowledged their tricolor problems, and is Beta testing a new light with a linear
power regulator instead of a switching
regulator. However, I was only able to find the old unit online, and it also requires a 3-wire
installation.
Yesterday I went to another boat where I had installed a MarineBeam replacement LED bulb in the tricolor. Tried the same test, and got no
interference. MarineBeam says their switching regulator does not have a square waveform, so creates less interference at VHF/
AIS frequencies.
We ordered a MarineBeam combined tricolor/anchor/strobe fixture this week. At $99, its less than half the
price of the competition. I'm going to bench test it for interference with a handheld before we go to the trouble of replacing fixtures at the top of the mast.
We are also going out this weekend, and I will test the effect of the AS on
AIS targets. I'll post again when I know more.