How do FM radio channels work?
Every FM station is a song racing from a studio, through a microwave dish, up a mast on a hill and into your radio at the speed of light. An RJ's mic and the playout computer's songs, ads and jingles meet on a mixing console.
Read how it works: How do FM radio channels work? · The history of FM radio · More boxes on Glassbox
Chapters in this interactive model
- Inside an FM station: Follow one song from the studio playlist, up a tower on a hill, and into your ear.
- What "98.3" means: The number on the dial, why stations sit 800 kHz apart, and how far-off cities share a frequency.
- Frequency modulation, live: How the sound nudges the carrier's frequency, how wide that makes a station, and why the stronger station wins.
- Stereo and RDS: a crowded baseband: How one FM signal carries left, right, a 19 kHz pilot and the station name for your car display.
- How far does a station reach?: Power, tower height, the curve of the Earth, and why FM fades in basements and flickers in traffic.
- FM in India: who is on air, and how it pays: Akashvani, private FM auctions, community radio, the news rule, ads and music, FM in phones, and what comes next.
This interactive model needs JavaScript and WebGL.