How to make Long-Range FM Transmitter Circuit-Weekend Projects

FM Transmitter circuit is one of the cool projects to build with a good range. The FM transmitter we are going to make is long-range although you can increase more range with the help of a large antenna.

An FM transmitter is a gadget that uses the standards of frequency modulation to broadcast sound provided at its input.
Typical FM transmitter design’s normally comply with the block graph below. Watch this video for step-by-step instructions.

Hardware Components

The following components are required to make FM Transmitter Circuit

S. No	Components	Value	Qty
1.	Vero PCB Board	–	1
2.	NPN Transistor	2N3904	2
3.	Variable Capacitor	(4-40pf)	1
4.	Ceramic Capacitor	0.1uF, 0.01uF, 4.7pF	2, 1, 1
5.	Inductor	0.1uH	1
6.	Resistors	100K, 10K, 1M, 100 ohm	1, 3, 1, 1
7.	Condenser Mic	–	1
8.	9V Battery	–	1

2N3904 Pinout

For a detailed description of pinout, dimension features, and specifications download the datasheet of 2n3904

FM Transmitter Circuit

Working Explanation

The sign energy of audio inputs into the transmitter is typically low therefore an amplifier is typically constructed to deliver the signal level up. Based on the preferred frequency for transmission (which is normally between the FM frequency band, 88MHz to 108MHz), the service frequency is generated using an oscillator circuit and blended with an Audio sign to create the modulated signal. The modulated signal is then passed thru a power amplifier at the transmission stage to create low impedance which is matched with the antenna.

Application

• The FM transmitters are used in the homes like sound systems in halls to fill the sound with the audio source.
• These are also used in cars and fitness centers.
• The correctional facilities have used FM transmitters to reduce the prison noise in common areas.