Chapter III
The Apparatus Used
6. General Outline
The production of electromagnetic waves requires a source of current, means for interrupting a unidirectional current (or an alternating current may be used), means for changing the interrupted or alternating current into low-frequency high-pressure currents, means for transforming these into high-frequency high-pressure oscillations, and means for utilizing these oscillations to form the electromagnetic waves.
At the receiving station means must be provided for intercepting the waves, and retransforming them into electrical oscillations; means for detecting the enfeebled oscillations, and for manifesting and translating them into readable signals.
7. The Induction Coil
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