QRP 1-Watt CW Transmitter

Circuit Diagram

How to Build It

1. Place the crystal and the oscillator transistor (Q1) on the board.
2. Connect the crystal between +12V and Q1's base through a 10K bias resistor.
3. Connect Q1's collector to +12V through a 2.5mH RF choke.
4. Connect a 100pF coupling capacitor from Q1's collector to the next stage.
5. Connect Q1's emitter to ground (GND).
6. Connect the second transistor's (Q2, the amplifier) base through a 4.7K resistor.
7. Connect Q2's collector to +12V through a second RF choke, then to a simple low-pass filter (coil + 2 capacitors) leading to the antenna.
8. Insert a Morse key into the +12V supply line.
9. Pressing the key sends a continuous signal on the crystal's frequency — test with a nearby receiver.

Bill of Materials