*Question E6B02:
Which characteristic of a Schottky diode makes it a better choice than a silicon junction diode for use as a power supply rectifier?*  

*Correct Answer is  D: Lower forward voltage drop*  

### AI Response: (may contain errors)  

The correct answer to the question about Schottky diodes is:

**D: Lower forward voltage drop**

### Explanation of the Correct Answer:
- **Lower Forward Voltage Drop**: Schottky diodes have a lower forward voltage drop (typically around 0.2 to 0.3 volts) compared to silicon junction diodes (which usually have a forward voltage drop of about 0.6 to 0.7 volts). This lower voltage drop results in higher efficiency and less power loss when used in power supply rectification, making Schottky diodes particularly advantageous in applications where efficiency is critical.

### Explanation of the Incorrect Choices:
- **A: Much higher reverse voltage breakdown**: 
  - Schottky diodes generally have a lower reverse voltage breakdown compared to silicon diodes. They are not designed for high reverse voltage applications, which makes this option incorrect.

- **B: More constant reverse avalanche voltage**: 
  - Schottky diodes do not exhibit avalanche breakdown like silicon diodes. Instead, they have a different failure mode. This characteristic does not apply to Schottky diodes, making this choice incorrect.

- **C: Longer carrier retention time**: 
  - Schottky diodes are majority carrier devices, meaning they do not have a significant carrier retention time like minority carrier devices (such as silicon junction diodes). This characteristic is not relevant to their performance as rectifiers, so this option is also incorrect.

### Summary:
- Schottky diodes are preferred for power supply rectification primarily due to their **lower forward voltage drop**, which enhances efficiency.
- The other options do not accurately describe the characteristics of Schottky diodes in comparison to silicon junction diodes. 

This understanding is crucial for selecting the right diode for specific applications in your amateur radio projects and beyond.