The Basic lessons · Station assembly, practice and safety · B-003-002

How FM Transmitters Work: From Voice to Radio Wave

This lesson explains how a microphone turns your voice into an electrical signal and how an FM transmitter changes frequency to carry that sound. You will learn which parts of the radio handle the most power and why frequency, not volume, is key to FM transmission.

This lesson is part of SignalPrep Pro. The subsection's 7 exam questions are free to practise: practise B-003-002.

What this subsection asks

• What does the microphone produce in an FM transmitter?
• The microphone of an FM transmitter:
• An FM transmitter's modulator:
• How is the oscillator in the FM transmitter different from oscillators in AM, CW, and SSB transmitters?
• In an FM transmitter, the frequency multiplier:
• In an FM transmitter, which stage produces a useful harmonic?
• In an FM transmitter, which stage draws the most electric power?