*Question G2A06:
Which of the following is an advantage of using single sideband, as compared to other analog voice modes on the HF amateur bands?*  

*Correct Answer is  D: Less bandwidth used and greater power efficiency*  

### AI Response: (may contain errors)  

The correct answer to the question about the advantages of using single sideband (SSB) compared to other analog voice modes on the HF amateur bands is:

**D: Less bandwidth used and greater power efficiency.**

### Explanation of the Correct Answer:
- **Less Bandwidth Used**: SSB typically occupies less bandwidth than amplitude modulation (AM). While AM requires about 10 kHz of bandwidth for a standard voice signal, SSB only requires about 3 kHz. This efficiency allows more channels to fit within the same frequency range.
  
- **Greater Power Efficiency**: In SSB, only one sideband (either upper or lower) is transmitted, and the carrier is suppressed. This means that more of the transmitter's power is used for the actual voice signal rather than being wasted on transmitting a carrier signal, leading to better power efficiency.

### Why the Other Choices are Incorrect:
- **A: Very high-fidelity voice modulation**: 
  - While SSB can provide good audio quality, it is not necessarily "very high-fidelity" compared to other modes like FM. FM can offer higher fidelity due to its wider bandwidth and noise immunity.

- **B: Less subject to interference from atmospheric static crashes**: 
  - SSB is not inherently less susceptible to atmospheric noise than other modes. In fact, all HF modes can experience static crashes, and the effectiveness of SSB in this regard depends more on the receiver's design and filtering capabilities.

- **C: Ease of tuning on receive and immunity to impulse noise**: 
  - SSB can be more challenging to tune than AM because it requires precise frequency alignment. While SSB can be somewhat more resistant to certain types of noise, it is not immune to impulse noise, which can affect all modes of transmission.

### Summary:
- SSB is advantageous due to its **less bandwidth usage** and **greater power efficiency**. 
- Other modes may offer better fidelity or different noise characteristics, but they do not match SSB's efficiency in bandwidth and power usage. 

This understanding is crucial for the Extra Class exam and practical amateur radio operations.