FM Transmitter Circuits

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In a frequency modulation (FM) transmitter, it is added by varying the radio signal's frequency slightly. Many other types of modulation are used.

In an FM (frequency modulation) transmitter the frequency of the carrier is varied by the audio signal. Angle modulation is the proper term for modulation by changing the instantaneous frequency or phase of the carrier signal. FM transmitters can be stereo as well and using a PLL tunning circuit you can achive a stable audio transmition on FM band.
 
True FM and phase modulation are the most commonly employed forms of analogue angle modulation. Direct FM (true Frequency modulation) is where the frequency of an oscillator is altered to impose the modulation upon the carrier wave. This can be done by using a voltage-controlled capacitor (Varicap diode) in a crystal-controlled oscillator or frequency synthesiser.
The frequency of the oscillator is then multiplied up using a frequency multiplier stage, or is translated upwards using a mixing stage, to the output frequency of the transmitter.
 
 In some indirect FM solid state circuits, an RF drive is applied to the base of a transistor. The tank circuit (LC), connected to the collector via a capacitor, contains a pair of varicap diodes. As the voltage applied to the varicaps is changed, the phase shift of the output will change.
 

Circuits




It has a range of up to 1/4 mile or more. It's great for room monitoring, baby listening and nature research. My Experience: FM transmitters remind me of my early years in electronics. When I was 8...

I'm freshman . I don't know what is exactly going on here but I made this fm transmitter. Could anyone please explain to me the different stages of this...

Using 555 as FM transmitter Circuit Diagram. The integrated circuit 555 has no limits, this FM transmitter circuit, the IC 555 is designed as an stable multivibrator as usual. But the tension contr...

Simple circuit to listen to aircrafts. One IC Transmitter Circuit Diagram Single Transistor Transmitter Circuit Diagram Wireless Power Generator Circuit Diagram Circuit Simple 100M VHF video Transm...

You can also place the transmitter circuit close to any loud speaker so that the microphone picks up the sound and transmits to the tuned FM radio. WATCH THE EXPERIMENT VIDEO ON YOUTUBE · FM transm...

This is a simple wireless FM transmitter circuit which uses RF communication to transmit the medium or low power FM signal. Its maximum range is 2 km.


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