*Question G2E04:
Which of the following is good practice when choosing a transmitting frequency to answer a station calling CQ using FT8?*  

*Correct Answer is  D: Find a clear frequency during the alternate time slot to the calling station*  

### AI Response: (may contain errors)  

When operating FT8, a digital mode used in amateur radio, it's important to understand the time slot system and how to effectively respond to a station calling CQ (a general call for any station to respond).

1. **Correct Answer: D - Find a clear frequency during the alternate time slot to the calling station**

   - **Explanation**: FT8 operates on a time-synchronized basis, with transmissions typically occurring in alternating 15-second time slots. If a station is calling CQ, they are transmitting during one time slot and listening during the alternate time slot. To successfully respond, you should transmit during the time slot when the calling station is listening. This means finding a clear frequency during the alternate time slot to the calling station's transmission.

2. **Why the other choices are incorrect**:

   - **A: Always call on the station’s frequency**  
     - This is not recommended because it can cause interference. FT8 is designed to allow multiple conversations to occur simultaneously on different frequencies within the same band. Calling on the same frequency can lead to overlapping signals, making it difficult for the calling station to decode your response.

   - **B: Call on any frequency in the waterfall except the station’s frequency**  
     - While this avoids direct interference, it does not address the timing issue. You must also ensure you are transmitting during the correct time slot when the calling station is listening.

   - **C: Find a clear frequency during the same time slot as the calling station**  
     - This is incorrect because if you transmit during the same time slot as the calling station, they will not be able to hear your response since they are transmitting at that time.

3. **Useful Rule of Thumb**:

   - **Time Slot Synchronization**: Always ensure your computer's clock is accurately synchronized to the correct time. FT8 relies on precise timing, and being off by even a few seconds can prevent successful communication.

By understanding the time slot system and choosing a clear frequency during the alternate time slot, you increase the likelihood of a successful contact using FT8.