The AM Forum

Watch the video and its pretty much self-explanitory. In the middle of the room, I can't hear the station. Move closer to the fan, it gets louder. Put the radio on the fan and it gets louder yet. Turn the radio so that the coils on the internal bar antenna are parallel to the motor's shaft and it gets as loud as possible. I turned off the fan to show there was no difference, the only difference I could make was pulling the plug, which I didn't do it the video, but it proved that the signal was coming in on the power lines. Now, here's what I can't figure out. It only seems to work on that frequency, which is 1280 khz. I turned the radio to a station on 1040 khz, which is closer, and it really didn't make a difference how close the radio was to the fan on that frequency, it still didn't come in that good. My guess is that the windings inside that motor are resonant at or around 1280, which is why that station comes in so good near the fan when the others don't. Something else that I noticed but couldn't tell whether it was from the motor itself or the fan blades messing with the audio, was that when I cut power to the fan, once it hit a certain speed, i heard a "swoosh-swoosh-swoosh" sound. I'm not sure if it was from the audio passing through the path of the fan blades, or some kind of effect caused by the windings rotating inside the motor changing the phase of the signal or something.
http://www.youtube.com/watch?v=rUD-WH3uoac (http://www.youtube.com/watch?v=rUD-WH3uoac)

What happens if you pull the plug and short the plug to complete the loop of the motor windings?  Maybe it will work as a loop antenna and the signal is not actually coming from the power lines.

Just a thought,
MorrisSWL

I know that pulling the plug does reduce the received signal, I have no idea what shorting the cord out will do, I haven't tried it yet.

I just tried shorting the plug, doesn't make a difference whether the plug is shorted or not, it doesn't work as good as it does when it is plugged in.