Radio Time MachineRF History Explorer

Travel through 130+ years of radio technology. Tap any era to see its signal waveform, hear its sound, and learn about the inventors who shaped wireless communication — from spark gap transmitters to WiFi 7.

Spark Gap

1887 – 1920

The first practical radio transmitters. A high-voltage spark across a gap created broadband electromagnetic pulses — noisy, inefficient, but revolutionary.

Listen plays a synthesized illustration of the era's character, not a recording.

Frequency: Broadband (Marconi-era sets ≈ 0.1 – 2 MHz)

Modulation: Damped oscillation (OOK)

Key Figures

Heinrich Hertz / Guglielmo Marconi

Hertz demonstrated the electromagnetic waves Maxwell had predicted (experiments 1886–1888). Marconi commercialised wireless telegraphy; his 1901 transatlantic signal went from Cornwall to Newfoundland.

Spark Gap — Damped oscillation (OOK)

Illustrative waveform, not to scale.

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How RF Technology Evolved

Analog Era (1887–1980)
From spark-gap telegraphy to AM, FM, and TV — engineers learned to shape continuous electromagnetic waves to carry voice, music, and television across vast distances.
Digital Revolution (1991–2010)
Digital modulation unlocked encryption, error correction, and spectral efficiency. GSM, WiFi, and early LTE transformed how billions connect.
Modern Wireless (2019–present)
5G NR and WiFi 7 push the boundaries with massive MIMO, beamforming, OFDMA, and multi-link operation for unprecedented speed and reliability.