*Question E4E04:
How can conducted noise from an automobile battery charging system be suppressed?*  

*Correct Answer is  D: By installing ferrite chokes on the charging system leads*  

### AI Response: (may contain errors)  

To suppress conducted noise from an automobile battery charging system, the correct answer is:

**D: By installing ferrite chokes on the charging system leads.**

### Explanation of the Correct Answer:
- **Ferrite chokes** are effective at suppressing high-frequency noise. They work by providing a high impedance to high-frequency signals while allowing low-frequency signals (like DC power) to pass through. This helps to filter out the noise generated by the alternator and other components in the charging system, preventing it from reaching the radio.

### Why the Other Choices are Incorrect:
- **A: By installing filter capacitors in series with the alternator leads**
  - This method is not effective because capacitors in series block DC current, which is necessary for the charging system to function. They may also not adequately suppress high-frequency noise.

- **B: By installing a noise suppression resistor and a blocking capacitor at the battery**
  - While this could help reduce some noise, it is not as effective as using ferrite chokes. Resistors can dissipate power and may not provide sufficient attenuation of high-frequency noise.

- **C: By installing a high-pass filter in series with the radio’s power lead and a low-pass filter in parallel with the antenna feed line**
  - This approach is overly complex and may not effectively target the specific noise generated by the charging system. High-pass filters can block desired low-frequency signals, and low-pass filters may not adequately address the noise coming from the charging leads.

### Summary:
- **Ferrite chokes** are the best choice for suppressing conducted noise from an automobile battery charging system due to their ability to filter out high-frequency interference without affecting the DC power needed for operation. 

This understanding will help you effectively address noise issues in your amateur radio setup.