Simple FM Transmitter 2N3904

Introduction

Learning grows when gets executed practically. It provides a person with a clear perspective of various things. So, to grasp the understanding process of frequency modulation we are here with the intriguing project of Simple FM Transmitter by using two transistors. Hence, the circuit works efficaciously in distant or close ranges. As you already know that there are different ways to transmit the data. Thus, in frequency modulation, the data is transferred by varying the frequency of carrier waves. Also, there are different ways to make this circuit. Thus, we are making it by using the two transistors FM transmitter. So, in this tutorial, we are going to make a “Simple FM transmitter.

Hardware Required

S.no	Component	Value	Qty
1.	NPN Transistor	2N3904	2
2.	Condenser MIC	–	1
3.	Inductor	0.1uH	1
4.	Variable Capacitor	4 to 40pF	1
5.	Ceramic Capacitor	1uF, 0.01uF, 4.7pF	2, 1, 1
6.	Resistor	10KΩ, 22KΩ, 100KΩ, 100R, 1KΩ	3, 1, 1, 1, 1

Circuit Diagram

Working Explanation

To make the simple FM transmitter, we are using the condenser microphone that provides the audio signal. When the circuit gets the audio signal from the microphone, it converts the signal into an electrical signal and then that signal penetrates at the base of the transistor which increases the amplitude of the signal. The signal gets more amplified by the transistor Q2. To generate the carrier waves, we have created the tank circuit using a capacitor and inductor. Here we are using the variable capacitor which changes the resonant frequency for fine modification. We connected the antenna to send the carrier waves. Now you can hear the audio signal given to this circuit on any of the radios in a close range.

Application and Uses

• We can use it on portable audio devices.
• In car radios, etc.
• Sound systems.