• 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.
         (use 6 V/0.25 A bulb)
         (make sure there are no other transmitters nearby)
         (select a station with a strong signal, set volume control at 9 o'clock)