When I point my guitar pickups towards my desktop computer from several feet (2 1/2 - 3) away, I can hear a lot of buzzing/clicking, depending on what the computer is doing (idling vs, say, playing video). Are the pickups picking up radio interference from the computer which is being demodulated by the amplifier, or are they inductively coupled to the computer, despite the lack of coils & distance?
I have trouble believing that it's radio interference that they're detecting (I've never gotten an AM signal through my amp, for example), but given the distance, I also have trouble believing that inductance is generating the noise. Can anyone shed some light on this?
EDIT: To clarify, I'm talking about a single coil pickup, not a humbucker. I'm not really interested in reducing noise, it's not an issue for me. I'm just curious about what mechanism is involved.