5H40.38  HOMEMADE SPEAKER


  • A drink cup with a voice coil in the bottom functions as an audio speaker.
  • Volume should be below maximum to avoid burning out the lightbulb.
  • CAUTION: keep magnet at least 30 cm away from ALL other ferromagnetic materials.

         (select a station with a strong signal, set volume control at 9 o'clock)

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