*Question E3B07:
What effect does lowering a signal’s transmitted elevation angle have on ionospheric HF skip propagation?*  

*Correct Answer is  C: The distance covered by each hop increases*  

### AI Response: (may contain errors)  

Lowering a signal’s transmitted elevation angle affects how HF signals propagate via the ionosphere. Let's break down the correct answer and the other choices.

### Correct Answer: C - The distance covered by each hop increases

- **Explanation**: When you lower the elevation angle of a transmitted signal, the signal is directed more horizontally rather than steeply upwards. This allows the signal to travel further before it is refracted back to Earth by the ionosphere. As a result, the distance covered by each hop (the distance between the point of transmission and the point of reflection back to Earth) increases. This is beneficial for long-distance communication.

### Why the Other Choices are Incorrect:

- **A: Faraday rotation becomes stronger**  
  - **Explanation**: Faraday rotation is the rotation of the plane of polarization of a radio wave as it passes through a magnetized medium, such as the ionosphere. While the elevation angle can influence the path of the signal, lowering the angle does not inherently increase Faraday rotation. The effect is more related to the frequency and the characteristics of the ionosphere rather than the elevation angle.

- **B: The MUF decreases**  
  - **Explanation**: The Maximum Usable Frequency (MUF) is the highest frequency that can be used for communication via the ionosphere at a given time. Lowering the elevation angle does not decrease the MUF; in fact, it can allow for better use of higher frequencies by extending the range of the signal. The MUF is influenced by factors such as solar activity and the ionospheric conditions, not directly by the elevation angle.

- **D: The critical frequency increases**  
  - **Explanation**: The critical frequency is the highest frequency that can be reflected by the ionosphere at a vertical incidence. Lowering the elevation angle does not increase the critical frequency; it is determined by the ionospheric electron density. The critical frequency is more related to the ionospheric layer's characteristics rather than the angle of transmission.

### Summary

- Lowering the elevation angle increases the distance covered by each hop, making it advantageous for long-distance HF communication.
- Other options do not accurately reflect the effects of changing the elevation angle on ionospheric propagation. 

This understanding is crucial for optimizing HF communication strategies in amateur radio.