*Question E2E02:
Which of the following synchronizes WSJT-X digital mode transmit/receive timing?*  

*Correct Answer is  B: Synchronization of computer clocks*  

### AI Response: (may contain errors)  

WSJT-X is a popular software suite used for weak-signal digital communication modes, such as FT8 and JT65. These modes require precise timing to ensure that transmissions and receptions are synchronized.

### Explanation:

1. **Correct Answer: Synchronization of computer clocks**
   - WSJT-X digital modes rely on precise timing to coordinate when stations transmit and receive. This is crucial because these modes often use very short transmission windows (e.g., 15 seconds for FT8). To achieve this synchronization, the computer clocks of all participating stations must be accurately aligned, typically within a second or two. This is usually done using network time protocol (NTP) services to keep the computer's clock accurate.

2. **Why the other choices are incorrect:**
   - **A: Alignment of frequency shifts**
     - While frequency stability is important, WSJT-X modes do not synchronize timing based on frequency shifts. Frequency alignment ensures that signals are on the correct frequency, but it does not handle timing synchronization.
   - **C: Sync-field transmission**
     - There is no specific "sync-field" transmission used in WSJT-X modes for timing. The synchronization is achieved through accurate clock settings, not through a transmitted field.
   - **D: Sync-pulse timing**
     - WSJT-X does not use sync-pulse timing for synchronization. The timing is managed by ensuring that all participating stations have synchronized clocks.

### Useful Tips:
- **Network Time Protocol (NTP):** Ensure your computer is set to synchronize its clock with an NTP server. This is crucial for participating in WSJT-X modes.
- **Timing Tolerance:** For modes like FT8, the timing tolerance is typically within 1-2 seconds. If your clock is off by more than this, you may miss transmissions or have difficulty decoding signals.

By keeping your computer's clock synchronized, you ensure that your transmissions and receptions are properly timed, allowing for successful communication using WSJT-X digital modes.