Need help understanding how a radio works

  • Thread starter Thread starter x64bob
  • Start date Start date
  • Tags Tags
    Radio Works
Click For Summary

Discussion Overview

The discussion centers around understanding the operation of a radio, specifically how a microphone's electrical signal is integrated into an oscillator circuit. The scope includes technical explanations of modulation techniques and circuit schematics.

Discussion Character

  • Technical explanation, Conceptual clarification, Debate/contested

Main Points Raised

  • One participant inquires about how the electrical signal from a microphone is inserted into an oscillator circuit, suggesting that the microphone alters current based on sound vibrations.
  • Another participant confirms the microphone's function and suggests that the altered current enters the oscillator circuit through a wire, but questions the simplicity of this explanation and asks for a schematic.
  • A third participant introduces the concept of "modulation," explaining that it allows one signal to change characteristics of another, specifically mentioning amplitude modulation (AM) and frequency modulation (FM) as techniques used in radio.
  • This participant notes that amplitude modulation can be achieved with a transformer, while frequency modulation typically uses a voltage-controlled oscillator (VCO).
  • A later reply includes a request for feedback on a schematic that the original poster has in mind, indicating a practical application of the discussed concepts.

Areas of Agreement / Disagreement

Participants express varying levels of understanding about the integration of microphone signals into oscillator circuits, with some agreement on the basic functions of microphones and modulation, but no consensus on the specifics of the circuit design or operation.

Contextual Notes

The discussion includes assumptions about the microphone's operation and the specifics of modulation techniques, but lacks detailed mathematical or schematic analysis of the proposed circuit.

x64bob
Messages
10
Reaction score
0
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?
 
Physics news on Phys.org
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?
 

Attachments

  • scgematic.JPG
    scgematic.JPG
    2.6 KB · Views: 538
Last edited:

Similar threads

  • · Replies 20 ·
Replies
20
Views
4K
  • · Replies 14 ·
Replies
14
Views
6K
  • · Replies 1 ·
Replies
1
Views
3K
Replies
3
Views
3K
  • · Replies 37 ·
2
Replies
37
Views
5K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 17 ·
Replies
17
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
20
Views
3K
  • · Replies 13 ·
Replies
13
Views
3K