Need help understanding how a radio works

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A microphone converts sound vibrations into an electrical signal by altering current flow. This altered current must connect to a preamplifier or amplifier before entering the oscillator circuit. The process of integrating the audio signal with the oscillator is known as modulation, which can be either amplitude modulation (AM) or frequency modulation (FM). AM can be achieved using a transformer, while FM typically utilizes a voltage-controlled oscillator (VCO). A schematic was shared to illustrate the proposed radio design, indicating the microphone signal as the gate current.
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with the help of an oscillator you create a frequency but how exactly do you insert the electric signal you've gained from a microphone into that frequency?
if i understood the microphone right it transfers the vibrations into electrical form by altering let's say the current so that different amount of electrons pass trough the wire. then how do that altered current enter the oscillator circuit?
 
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x64bob said:
if i understood the microphone right it transfers the vibrations into electrical form by altering let's say the current so that different amount of electrons pass trough the wire.

Yes.

then how do that altered current enter the oscillator circuit?

The microphone would have to be connected (electrically) to the either a preamplifier or an amplifier. So I guess the answer to the question of how the altered current enters the oscillator would be: "Through a wire". But that seems like too simple of an answer. Do you have a schematic of the system you have in mind?
 
The concept you're looking for is called "modulation." Modulation is the technique of allowing one signal to change characteristics of another. In the case of a radio, the low-frequency audio signal is used to change either the amplitude (AM) or frequency (FM) of the carrier, which is generated by the oscillator.

Amplitude modulation can be done with nothing more than a transformer. Frequency modulation is commonly done with a voltage-controlled oscillator (VCO).

- Warren
 
thanks for the help all.
here's the schematic of what i have in mind, would it work as a simplified schematic for a radio where the Gate current is the mic signal?
 

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