Buzz in headsets with new Modulator

[dingdong]

I just replaced my headlight modulator after the old on failed. The new one creates a buzz through the intercom at each modulation. The old one didn't do this. Very annoying. I have to turn the intercom completely off to get rid of it. I wonder if there is some sort of filter that will eliminate this. It is plug and play and is located in the same position as the old one. I really don't want to have to return or exchange this one.

[WingAdmin]

It's really down to how quickly the modulator turns the light on and off. If it's doing an instantaneous switch on/off/on/off, it's going to be pumping a bunch of harmonics into the +12v bus, which you will then hear in the intercom.

Modulators that ramp the light up and down more gradually (think a sine wave curve instead of a block on/off) won't put those harmonics into the bus.

I had this problem on my GL1500. I liked the modulator, so I built a damping circuit - basically a box with a big toroid choke and some massive electrolytic capacitors, that damp how quickly the current can change up and down. It definitely helped, but did not completely eliminate the noise. However it was tolerable.

Eventually I switched to a HID headlight, which meant no modulator. I moved the modulator to modulate the LED position lights instead. The LEDs pull next to no current, so there was no problem with noise, and I removed the damping circuit components I had built into the harness.

Incidentally, the modulator I was using was a Kisan Pathblazer - what is the one you're having problems with?

[dingdong]

Kisan Pathblazer of course. The older one was also. Totally different physically though. Newer isn't always better, probably just cheaper to build.