*Question G4D10:
How close to the lower edge of a band’s phone segment should your displayed carrier frequency be when using 3 kHz wide LSB?*  

*Correct Answer is  A: At least 3 kHz above the edge of the segment*  

### AI Response: (may contain errors)  

When using Lower Sideband (LSB) for voice communication, the carrier frequency is suppressed, and the transmitted signal occupies a bandwidth below the carrier frequency. For a 3 kHz wide LSB signal, the entire signal bandwidth extends from the carrier frequency down to 3 kHz below it.

### Explanation:

1. **Correct Answer: At least 3 kHz above the edge of the segment (Choice A)**
   - Since the LSB signal extends downward from the carrier frequency, you need to ensure that the entire 3 kHz bandwidth of your signal stays within the band. If your carrier frequency is exactly at the band edge, the lower part of your signal will fall outside the band. Therefore, to keep the entire signal within the band, the carrier frequency should be at least 3 kHz above the lower edge of the band.

2. **Why the Other Choices are Incorrect:**
   - **Choice B: At least 3 kHz below the edge of the segment**
     - This would place the entire signal outside the band, which is not allowed.
   - **Choice C: At least 1 kHz below the edge of the segment**
     - This would also place the entire signal outside the band, as the signal extends 3 kHz below the carrier frequency.
   - **Choice D: At least 1 kHz above the edge of the segment**
     - This would mean that 2 kHz of the signal would still fall outside the band, as the signal extends 3 kHz below the carrier frequency.

### Rule of Thumb:

- For LSB, ensure the carrier frequency is at least the bandwidth of the signal (3 kHz in this case) above the lower edge of the band to keep the entire signal within the band limits.