Ламповый передатчик. Шарманка.

Introduction

This tutorial will guide you through the process of building a low-power AM radio transmitter designed for shortwave broadcasting. By following these steps, you will gain a deeper understanding of radio transmission and learn how to create your own simple transmitter.

Step 1: Gather Materials

Before starting your project, collect the necessary components. Here’s what you will need:

• Transistor: A suitable NPN transistor (e.g., 2N3904)
• Resistors: Various values (e.g., 10k ohm, 100 ohm)
• Capacitors: Different capacities for tuning (e.g., 10nF, 100nF)
• Inductor: A coil that can be made from insulated copper wire
• Power source: A battery or DC power supply (e.g., 9V)
• Antenna: A simple wire antenna, approximately 1-3 meters long
• Breadboard or PCB: For assembling the circuit

Step 2: Design the Circuit

Create a schematic for your AM transmitter. The key components include:

• Oscillator Circuit: This generates the radio frequency signal.
• Amplifier Stage: To boost the signal strength.
• Modulator: To combine audio input with the RF signal.

Schematic Overview

1. Connect the transistor in a common emitter configuration.
2. Use resistors to bias the transistor correctly.
3. Attach the inductor and capacitors to form the tank circuit, which will determine the frequency of transmission.

Step 3: Assemble the Circuit

Using your schematic, start building the circuit on a breadboard or PCB. Follow these steps:

1. Insert the transistor into the board.
2. Connect the resistors and capacitors as per your design.
3. Attach the inductor and ensure all connections are secure.
4. Finally, connect the antenna to the output stage.

Step 4: Power Up and Test

Once the circuit is assembled, connect your power source:

1. Double-check all connections before powering on to avoid shorts.
2. Turn on the power supply and observe the circuit.
3. Use a radio receiver tuned to the expected frequency to check for transmission.

Troubleshooting Tips

• If you don’t hear any signal, check:
  • The power supply connections.
  • The orientation of the transistor.
  • Connections of the inductor and capacitors.

Step 5: Tuning the Transmitter

To optimize your transmission, you may need to tune the circuit:

1. Adjust the variable capacitor in the tank circuit to change the frequency.
2. Use a frequency counter or a radio receiver to find the correct frequency for clear transmission.

Conclusion

Congratulations on building your own low-power AM transmitter! You now have a basic understanding of radio transmission and the components involved. For further experimentation, consider:

• Modifying the circuit to enhance range.
• Exploring different components for better performance.
• Experimenting with different audio sources for broadcasting.

With practice, you can refine your skills and create more advanced radio projects. Enjoy exploring the world of radio transmission!