Building your own low cost FM radio transmitter can be a fun electronics project that allows you to broadcast music or voice audio over the FM band. With just a few easy to find parts, you can assemble a simple FM transmitter in an evening.

What You'll Need

Constructing an FM transmitter is relatively straightforward. Here are the components you'll need:

Transmitter Module

The core of the transmitter is a small FM transmitter module. These are readily available for purchase online for $5-$10. The module has an audio input and broadcast antenna output, and handles all the RF modulation and amplification.

Common types are:

Power Supply

The module requires a steady DC power supply, typically 9V. You can use:

Audio Input Source

You'll need a way to feed audio into the module. Options include:


A simple wire antenna is needed for broadcasting the FM signal. The longer the better - aim for around 3 feet / 1 meter. The wire can be stiff copper wire or flexible insulated hookup wire.

Circuit Assembly

The transmitter module handles the difficult RF work. Connecting it to the other components is straightforward.

1. Connect Power

2. Connect Audio Input

3. Attach Antenna Wire

Setup and Usage

With the wiring complete, you're ready to start broadcasting:

Tune Transmitter Frequency

Position Antenna

Play Audio Source

And that's it! Enjoy your DIY low cost FM radio station. Just be aware that operating transmitters without a license can violate broadcasting regulations. Keep your transmitter power low and use it responsibly.

Going Further

Some ideas for expanding your transmitter:

So grab a module and have fun broadcasting over FM radio! Let me know if you build your own station - I'd love to hear how it turns out!