Forrest M. Mims Jameco Puzzler 10 A Non-Electronic Voice Transmitter by Forrest M. Mims III

Radio disk jockey D.J. Smith organized a stunt to raise donations for a charity by conducting his radio show for one week while suspended from a 150-feet tall crane. A cell phone with a solar charger served as D.J.'s only link to the radio station. His little home in the sky included foil-wrapped freeze-dried meals, bottled water, binoculars, pencil, notebook, paper clips, rubber bands, pocket knife, MP3 player, and a portable radio. The weather cooperated with light wind, clear skies and pleasant temperatures. All went well until D.J. dropped his cell phone to the concrete below. The stunt rules prevented any physical contact between D.J. and the ground. How did he continue his show?

Figure 1. How did D.J. continue his charity radio broadcasts after dropping his cell phone?

Voice Transmitter Puzzle Hints

D.J. Smith's radio station employed an engineer with a knowledge of history who was familiar with Alexander Gram's Bell invention in 1880 of the world's first wireless electronic voice communications device. The engineer quickly formulated a solution to the problem and broadcast the details over the radio station transmitter, which D.J. could hear using his radio. After writing down the engineer's instructions in his notebook, D.J. assembled a voice transmitter that the engineer below received with a custom receiver that he built. After some experimentation, D. J. and the engineer were able to continue the radio program, albeit with less fidelity than the dropped cell phone had provided. D.J. listened to callers over his portable radio, using a headset to eliminate audio feedback when he was speaking to his audience via the engineer's receiver below.

What kind of voice transmitter did D.J. make?

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