3Watt AM Radio Transmitter circuit
Circuits DIY HF QRP Transmitter

How to Build a 3-Watt AM Radio Transmitter

There is something magical about hearing your own voice or music coming through a vintage tube radio from across the room—or across the neighborhood. While many low-power “flea” transmitters struggle with range, this 3-Watt AM monster brings some real “punch” to the Medium Wave band.

In this project, we’re stepping up the power. Using the classic BD139 transistor and a rock-steady crystal oscillator, we’ll build a transmitter that balances simplicity with performance. Whether you’re a Part 15 enthusiast or just want to experiment with AM modulation, this circuit is the perfect way to become your own local broadcaster. Let’s get on the air!