Radio-wave production — the chain leaves the bench

Drive an antenna with the oscillator and the wave departs at c: λ = c/f — sealed: the 1.591 MHz LC wave is ≈ 188 m long (floor(c·2π·10⁻⁷) = 188): https://narrowhighway.com/s/1ee0d3ed486453eee0967146a531984888709198b39fb16a7b2c2a5f58ef1b73 . A half-wave dipole for it spans ~94 m — which is why AM stations use towers and crystal radios use long wires. Scale the cavity up from the bench to the planet and the same physics is the Schumann resonance: lightning the oscillator, the Earth-ionosphere gap the tuned circuit.