*Question T8A07:
What is a characteristic of single sideband (SSB) compared to FM?*  

*Correct Answer is  C: SSB signals have narrower bandwidth*  

### AI Response: (may contain errors)  

To understand the characteristics of single sideband (SSB) compared to frequency modulation (FM), let's analyze the options provided.

### Correct Answer: C: SSB signals have narrower bandwidth

- **Explanation**: 
  - SSB is a form of amplitude modulation (AM) that uses only one of the sidebands and suppresses the carrier. This results in a significant reduction in bandwidth.
  - The bandwidth of an SSB signal is typically about $2 \times f_m$, where $f_m$ is the maximum frequency of the modulating signal. In contrast, FM signals have a wider bandwidth due to the frequency deviation caused by modulation.

### Why the Other Choices are Incorrect:

- **A: SSB signals are easier to tune in correctly**  
  - **Explanation**: Tuning SSB signals can be more challenging than FM signals. SSB requires precise tuning to the correct frequency because the carrier is suppressed. FM signals, with their wider bandwidth and presence of a carrier, are generally easier to tune.

- **B: SSB signals are less susceptible to interference**  
  - **Explanation**: While SSB can be more efficient in terms of power and bandwidth, it is not necessarily less susceptible to interference. Both SSB and FM can experience interference, but FM is often more resistant to noise due to its method of modulation, which can reject amplitude variations.

- **D: All these choices are correct**  
  - **Explanation**: Since options A and B are incorrect, this choice cannot be correct.

### Summary of Key Points:
- **SSB Bandwidth**: 
  - SSB bandwidth is narrower than FM, making it more efficient for communication.
- **Tuning Difficulty**: 
  - SSB requires more precise tuning compared to FM.
- **Interference Susceptibility**: 
  - FM is generally more resistant to noise and interference than SSB.

This analysis helps clarify the characteristics of SSB compared to FM, focusing on bandwidth, tuning, and interference.