*Question G2A02:
Which mode is most commonly used for voice communications on the 160-, 75-, and 40-meter bands?*  

*Correct Answer is  B: Lower sideband*  

### AI Response: (may contain errors)  

In amateur radio, different bands have conventions for which sideband to use for voice communications. Here's how it breaks down for the 160-, 75-, and 40-meter bands:

1. **Correct Answer: Lower sideband (LSB)**  
   - **Explanation**: On the HF bands, the convention is to use lower sideband (LSB) for voice communications on frequencies below 10 MHz. This includes the 160-meter, 75-meter, and 40-meter bands. This is a long-standing tradition in amateur radio.

2. **Why the other choices are incorrect**:
   - **Upper sideband (USB)**: This is typically used for frequencies above 10 MHz, such as the 20-meter, 17-meter, and higher bands. Therefore, it is not the standard for the 160-, 75-, and 40-meter bands.
   - **Suppressed sideband**: This term is not commonly used to describe a mode of operation. It refers to a technique where one of the sidebands is suppressed in a single sideband (SSB) transmission, but it doesn't specify which sideband is used.
   - **Double sideband (DSB)**: This mode transmits both sidebands and is not typically used for amateur voice communications due to its inefficiency compared to single sideband (SSB) modes.

**Rule of Thumb**:  
- **Below 10 MHz**: Use Lower Sideband (LSB)  
- **Above 10 MHz**: Use Upper Sideband (USB)  

This rule helps operators remember which sideband to use based on the frequency band they are operating in.