In this article, you will see how to make an FM receiver. In order to transmit the audio signal to the longer distance, we use modulation technique. But we have the constraint called noise. We know noise effect on amplitude. By taking this point into consideration we modulate the frequency of the signal. FM can also be called as frequency modulation. To transfer FM signal from transmitter to receiver, transmitter consists of modulator and receiver consists of the demodulator.
There are many types of FM receivers. Even though there are many FM receivers, the basic thing that all FM radios require is an antenna sensitivity and tunning. A best FM transmitter transmits the signal of the narrow band so that, it does not interfere with other frequencies and save the bandwidth. As there is narrow bandwidth, the receiver must have the ability to tune to a particular frequency with high stability. The FM receiver must able to sense the all the channels available. A good FM receiver must have less effect of noise.
An FM receiver is an FM demodulated, where the FM signal is feed by receiving with an antenna. The FM signal feed is equal to the tunning frequency.
Receive Signal of particular frequency –> FM Demodulation –> Amplification of the signal
In demodulation, we remove the carrier signal from the frequency modulated signal to get the original audio signal.
- IC – LM386 x1
- T1,T2 – BF494
- R1,R2 – 10KΩ
- R3 – 1KΩ
- R4 – 10Ω
- VR(Variable Resistor) – 22K
- C1 – 220nF
- C2 – 2.2nF
- C3,C6 – 100nF
- C5,C4 – 10uF
- C7 – 47uF
- C8 – 220uF
- C9,C10 – 100uF
- VC(Variable Capacitor) – 22pF
- Inductor – 4 turn, 4mm diameter, 22SWG
- Speaker (8Ω)
You can tune the frequency by tuning Variable capacitor. You can adjust the volume by tuning variable resistor. Here LM386 is used to amplify the audio signal received in order to drive the speaker. The gain of the amplifier is controlled by adjusting variable resistor.
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