Step 1: Gather the necessary tools and materials.
- Portable radio
- 3.5mm audio jack
- Soldering iron and solder
- Wire stripper
- Heat-shrink tubing
- Screwdriver
- Electrical tape
Step 2: Open the portable radio.
- Use the screwdriver to remove the screws holding the radio's case together.
- Be careful not to lose any of the screws.
- Once the screws are removed, gently pry open the case.
Step 3: Locate the audio input circuit.
- Inside the radio, look for the audio input circuit.
- This is usually a small circuit board with a number of connections.
- It may be labeled as "AUX IN" or something similar.
Step 4: Connect the audio jack to the circuit board.
- Strip the ends of the audio jack wires (usually red, white, and ground)
- Solder the red wire to the positive terminal of the audio input circuit.
- Solder the white wire to the negative terminal.
- Solder the ground wire to the ground terminal.
- Make sure the connections are secure and there is no solder bridging between terminals.
Step 5: Insulate the connections.
- Use heat-shrink tubing to insulate the soldered connections.
- This will prevent any shorts or accidental contact with other components.
Step 6: Reassemble the radio.
- Carefully put the radio back together, ensuring all the components are properly seated.
- Replace the screws and make sure the radio is securely closed.
Step 7: Test the auxiliary input.
- Connect an audio source (such as a smartphone or MP3 player) to the newly installed auxiliary input.
- Turn on the radio and select the auxiliary input source.
- You should now be able to hear the audio from the connected device playing through the portable radio.
Remember to take necessary precautions when working with electronic components, such as unplugging the radio from any power source before starting the modification, and be careful not to damage any existing circuitry during the process. If you are unsure about any of the steps, consider consulting with an expert or someone experienced in electronics modifications.