MEDIUM-POWER FM TRANSMITTER(walkie-talkie)

FM TRANSMITTER circuitry

The components need to prepare it are:
    * Coil (Inductance +reluctance) .
    * Capacitor.
    * Resistor.
    * Mic.
    * ON OFF switch .
    * Transistor .
    * Antenna ( it doesn't need any element just straight wire act as antenna ).The range of this FM transmitter is around 100 metres at 9V
DC supply.
The circuit comprises three stages. The first stage is a microphone preamplifier

built around BC548 transistor. The next stage is a VHF oscillator wired
around another BC548. (BC series transistors are generally used in low-frequency
stages. But these also work fine in RF stages as oscillator.) The third
stage is a class-A tuned amplifier that boosts signals from the oscillator. Use
of the additional RF amplifier increases the range of the transmitter.
Coil L1 comprises four turns of 20SWG enamelled copper wire wound
to 1.5cm length of a 4mm dia. air core. Coil L2 comprises six turns of 20SWG
enamelled copper wire wound on a 4mm dia. air core.
Use a 75cm long wire as the antenna. For the maximum range,
use a sensitive receiver. VC1 is a frequency-adjusting trimpot. VC2
should be adjusted for the maximum range. The transmitter unit is powered
by a 9V PP3 battery. It can be combined with a readily available FM
receiver kit to make a walkie-talkie set as shown in Fig. 3.

This is only transmitter we have posted  receiver to complete full walkie-talkie see the IR MUSIC TRANSMITTER AND RECEIVER

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