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




Before you proceed, please see the schematic given below. In the schematic, you will see the components required for making an FM transmitter, The transmission range of this circuit is approximatel...

This is FM transmitter in VHF range. As Figure 1 Sonar with up to 2 watts, when used with a supply voltage of about 24V. In the case of applications typically do not want a high transmission. 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...

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...

When I was 8, I came across Art Swan's FM transmitter circuit. At the time I had no idea of where I'm supposed to buy the parts, so I recycled mine out of junk. I guess the biggest struggle that yo...

Eltronicschool. - There are many FM transmitter circuit schematic that will give us satisfy when build it. In here we will build very simple FM transmitter with circuit schematic. With simple compo...


Simple FM Transmitter Circuit


Weekend Projects - Super Simple FM Transmitter


10km range 6W FM transmitter (2SC1971), circuit diagram


Basics of FM Transmitter