A radio tuner receives radio broadcasts and converts them into audio-frequency signals which can be fed into an amplifier driving a loudspeaker. FM tuner, AM tuner, DAB tuner, etc. are types of radio tuner dealing with transmissions using different methods of modulation. The term tuner is used both for part of a radio receiver which also contains an amplifier section and for a boxed piece of equipment to be connected to a separate amplifier.
Tuners work using a principle called resonance. That is, tuners resonate at, and amplify, one particular frequency and ignore all the other frequencies in the air. It is easy to create a resonator with a capacitor and an inductor.
The tuner causes the radio to receive just one sine wave frequency. Now the radio has to extract e.g. a DJ's voice out of that sine wave. This is done with a part of the radio called a detector or demodulator. In the case of an AM radio, the detector is made with an electronic component called a diode.
The radio next amplifies the clipped signal and sends it to the speakers (or headphones). The amplifier is made of one or more transistors (more transistors means more amplification and therefore more power to the speakers).
What you hear coming out the speakers is the voice of the DJ!
In an FM radio, the detector is different, but everything else is the same. In FM, the detector turns the changes in frequency into sound, but the antenna, tuner and amplifier are largely the same.
A typical modern Hi-Fi tuner: The Yamaha RX-797
With 2x100W and a large frequency response, the RX-797 is a must-have item for an optimal multimedia configuration.
The RX-797 has a complete connectivity including input especially for CD and DVD players, and even inputs/outputs for audio-video peripherals on zone 2 of the connection panel. This zone 2 is controllable using the independent remote control supplied with the amplifier.
Discover impressive audio quality from the RX-797 thanks to its optimisation mode "CD Direct Amplification" and its "Pure Direct" sound mode.
Listen and preset your favourite radio stations using the RX-797 or simply set up you very own powerful and high-performing home cinema.