100Mhz AM-FM TRANSMITTER

1387

1d 00:54:41

The right transistor, inductor and two caps form a Colpitts type oscillator that generate the actual radio waves. The left transistor is just an audio amplifier which will amplify the signal and feed it to oscillator.

*******************************************************

EDIT : This is an AM transmitter, not a FM transmitter.
It may work with a cheap (and old) FM receiver, but probably not with a modern one. This circuit design is very old. 

Sure, it will transmit in the FM band. Problem is that most modern FM receivers use balanced detectors which will ignore AM. Older ones used a simple FM detector (slope detector) that was much more sensitive to AM.

*******************************************************

Antenna of 8"-10" inches is required at collector of oscillator for circuit to transmit. 

A.C source can be replaced  by mic. 

Input signal frequency is selected 10Mhz otherwise the oscillations would not be visible. The circuit will also work in audible frequency range in practice but not in simulation due to simulation speed issues.

published 9 years ago

Nikolay_S

9 years ago

It's amplitude modulation only. This is FM: http://everycircuit.com/circuit/5189263645736960

sumitdhingra

9 years ago

Yes, you are right. The circuit amplitude modulate the signal but the frequency of signal lies in fm range that's why it's easily picked by fm radio because most fm radio are poorly build and pick up AM modulated wave lying in their range. I have written all this in description too.

AhmedO

9 years ago

Like it

ROCKETBUSTER

9 years ago

Hey this's AM

sumitdhingra

9 years ago

Read description man!

Ali_90

9 years ago

Could you send me calculation work of your circuit?thanks

Ali_90

9 years ago

Cell_legend@hotmail.com

sumitdhingra

9 years ago

@Ali_90: As you can see, I made the circuit a month ago. I don't remember where would that page be where I did my calculations. Tell me where is problem and I will try to help you..

add comment in editor

EveryCircuit is an easy to use, highly interactive circuit simulator and schematic capture tool. Real-time circuit simulation, interactivity, and dynamic visualization make it a must have application for professionals and academia. EveryCircuit user community has collaboratively created the largest searchable library of circuit designs. EveryCircuit app runs online in popular browsers and on mobile phones and tablets, enabling you to capture design ideas and learn electronics on the go.