Motor_Start_June_23_2010_7kHz_BFO-For_Freesound.wav

If you think a universal (commutator and brushes) motor is loud, it's what you're NOT hearing that is loud, that is, the radio waves. This is a recording of VLF at 5 kHz when such a motor turns on (Electric Field Reception). You can also hear the sound of the power grid humming. Recorded with a wire running out my window connected to a discarded FM whip antenna stuck into the ground for positive signal, and the house's ground for negative signal, then hooked directly into the BT878 tuner ADC. Then I used the tuner program I wrote to transpose from 5 kHz to DC.