*Question G2E07:
Which of the following is required when using FT8?*  

*Correct Answer is  B: Computer time accurate to within approximately 1 second*  

### AI Response: (may contain errors)  

FT8 is a digital mode used in amateur radio that relies on precise timing for successful communication. Here's why the correct answer is B, and why the other choices are incorrect:

1. **Correct Answer: B: Computer time accurate to within approximately 1 second**
   - FT8 uses time-synchronized transmissions, typically in 15-second intervals. For the software to decode signals correctly, your computer's clock must be accurate to within about 1 second. This ensures that your transmission and reception windows align with those of other stations.

2. **Incorrect Choices:**
   - **A: A special hardware modem**
     - FT8 does not require a special hardware modem. It uses a computer with sound card capabilities to process audio signals. Software like WSJT-X handles the modulation and demodulation of FT8 signals.
   - **C: Receiver attenuator set to -12 dB**
     - There is no specific requirement for setting the receiver attenuator to -12 dB for FT8. The attenuator setting depends on the signal conditions and the receiver's performance, not a fixed value.
   - **D: A vertically polarized antenna**
     - FT8 can be used with any antenna polarization. The choice of antenna polarization depends on the specific communication path and conditions, not a requirement of the FT8 mode itself.

In summary, the critical requirement for FT8 is accurate computer time synchronization, which ensures proper timing for the digital communication process.