Small FM Transmitter Circuit

A very basic and small FM transmitter circuit has been discussed in this article, using a single transistor transmitter circuit, which is small yet is able to communicate over a distance of around 100 meter.

Small FM Transmitter Circuit Prototype


FM Transmitter Circuit Description

The offered system enables us to generate an FM transmitter, which includes an amplified microphone circuit, with compact dimensions (23 × 41 mm) that functions within a frequency range between 70 and 110 MHz. It could be picked up by a straightforward FM receiver a few tens of yards apart.

To be able to enhance the range, you should implement at point A a piece of 75 cm long wire that has an antenna function. Just one 9 volt battery is sufficient to power the device. The consumption is 5 mA only.


small FM transmitter circuitFor your set up of the components it really is adequate to follow along with cautiously the clues of the layout diagram.

Parts List for the proposed small FM transmitter circuit

All resistors are
Of 1/4 watt except if mentioned otherwise

R1 = 10 K
R2 = 10 K
R3 = 68 K
R4 = 120 Ohms
CI 100 nF .
C2 = 47 nF .
C3 = 470 pF .
C4 = 3.3 pF .
CV1 = 4- 20 pF trimmer.
L1 = 0.6 μH coil.
T1 = 2N2222
M = Electret MIC.
1 Clip for 9 volt battery.

Technical specifications :
Power consumption: 5mA

Distance Range: Over 100 meters