*Question E8A06:
What is the approximate ratio of PEP-to-average power in an unprocessed single-sideband phone signal?*  

*Correct Answer is  A: 2.5 to 1*  

### AI Response: (may contain errors)  

In an unprocessed single-sideband (SSB) phone signal, the Peak Envelope Power (PEP) is typically higher than the average power due to the nature of voice modulation. The PEP represents the maximum power level during the modulation cycle, while the average power is the mean power over time.

### Explanation:

1. **Correct Answer: 2.5 to 1**
   - The ratio of PEP to average power in an unprocessed SSB signal is approximately 2.5 to 1. This is because voice signals have peaks that are significantly higher than the average level, but not excessively so. The 2.5 to 1 ratio is a common rule of thumb for typical voice modulation without any additional processing.

2. **Why Other Choices Are Incorrect:**
   - **Choice B: 25 to 1**  
     This ratio is too high for an unprocessed SSB signal. Such a high ratio might be seen in signals with extreme peak levels or with certain types of processing, but not in typical unprocessed voice communication.
   
   - **Choice C: 1 to 1**  
     This ratio implies that the peak and average power are the same, which is not the case for voice signals. Voice modulation inherently has peaks that exceed the average power level.
   
   - **Choice D: 13 to 1**  
     This ratio is also too high for an unprocessed SSB signal. It suggests a much greater disparity between peak and average power than is typical for standard voice modulation.

### Useful Rule of Thumb:

- **PEP to Average Power Ratio for Unprocessed SSB:**  
  $$ \text{PEP-to-Average Power Ratio} \approx 2.5:1 $$

This rule of thumb helps in understanding the power dynamics of SSB signals and is useful for estimating power requirements and performance in amateur radio operations.