*Question E4D02:
Which of the following describes problems caused by poor dynamic range in a receiver?*  

*Correct Answer is  A: Spurious signals caused by cross modulation and desensitization from strong adjacent signals*  

### AI Response: (may contain errors)  

To understand the problems caused by poor dynamic range in a receiver, let's break down the correct answer and the other choices.

### Correct Answer: 
**A: Spurious signals caused by cross modulation and desensitization from strong adjacent signals**

- **Explanation**: 
  - Poor dynamic range means that a receiver struggles to handle a wide range of signal strengths. 
  - This can lead to **cross modulation**, where a strong signal interferes with the reception of a weaker signal, causing unwanted spurious signals.
  - **Desensitization** occurs when strong adjacent signals reduce the receiver's ability to detect weaker signals, making it difficult to distinguish between them.

### Why the Other Choices are Incorrect:

**B: Oscillator instability requiring frequent retuning and loss of ability to recover the opposite sideband**  
- **Explanation**: 
  - Oscillator instability is not directly related to dynamic range. It refers to issues with the local oscillator's frequency stability, which can affect tuning but does not specifically describe the effects of poor dynamic range.

**C: Poor weak signal reception caused by insufficient local oscillator injection**  
- **Explanation**: 
  - Insufficient local oscillator injection typically refers to issues with the oscillator's output level rather than dynamic range. While it can affect weak signal reception, it does not encompass the broader issues of spurious signals and desensitization.

**D: Oscillator instability and severe audio distortion of all but the strongest received signals**  
- **Explanation**: 
  - This choice focuses on audio distortion and oscillator issues, which are not the primary concerns of dynamic range. While strong signals may dominate, the key issue with poor dynamic range is the inability to handle both strong and weak signals effectively.

### Summary:
- **Dynamic Range**: The ability of a receiver to handle a wide range of signal strengths without distortion or loss of sensitivity.
- **Key Problems**: Cross modulation and desensitization are the main issues caused by poor dynamic range, leading to spurious signals.

Understanding these concepts will help you recognize the implications of dynamic range in receiver performance for the Extra Class exam.