Model making on FM transmitter.

Abstract→ The branch of communication Engineering. The study of transmitting radio wave in air. For communication process first transmitter is required.

Introduction

For communication in one way, radio is one of the best option. In Radio communication first transmitter is requird. Lets see about the FM transmitter.

FM transmitter

This F.M. transmitter has 3R.F. Stages. A variable frequency VHF oscillator, a class C driver stage and class C final power amplifier.

Block diagram of F.M. transmitter

As shown above block diagram, First stage is VHF (Very High Frequency) oscillator with 30 Mega Watt. Second stage is class C drive amp with 150 Mega Watt. Third and last stage of transmitter is class C power amp..with 1 Watt.

Circuit diagram of F.M. Transmitter

Circuit diagram of transmitter is shown above. At the one end of transmitter is power supply and antenna.

And another end is MIC or 3.5 High jack as input signal of transmitter.

Working of transmitter

This F.M. transmitter has 3 R.F. Stage. A variable frequency VHF oscillator, a class C drive stage and class C final power amplifier.

Power supply for this transmitter is 9 to 12 volts. At 12 volts supply, it will deliver 1 Watt R.F. power. With 70 cm telescopic antenna, range of transmitter is 50 meter. Range can be extended up to 1-5 KM. by using multi element yagi antenna having reflector, dipole, director elements.

Frequency of transmitter can be set within 88 – 108 MHz F.M. broad cast band by adjust the first trimmer. Adjust output trimmer (trimmer 2) for maximum range.

To power this transmitter use 10 nos of 1.2 volts nickel cadmium cells connected in series.

Applications

- For transmit any audio signal in near range.- For making our radio station.- By combining this transmitter module with

readily available F.M. Walkie-Talkie can be made.

- This is so small in size thus we can use this at any place at any time.

- Also can use for announcement in campus.

Conclusion

Transmitter is required for any type of communication.