*Question G2D11:
Why are signal reports typically exchanged at the beginning of an HF contact?*  

*Correct Answer is  A: To allow each station to operate according to conditions*  

### AI Response: (may contain errors)  

Signal reports are typically exchanged at the beginning of an HF contact to allow each station to operate according to conditions. Here's why:

1. **Correct Answer (A):**  
   - Exchanging signal reports at the start helps operators understand the quality of the communication link. This information allows them to adjust their equipment or operating techniques to optimize the contact. For example, if the signal is weak, an operator might increase power, adjust the antenna, or change frequency to improve communication.

2. **Incorrect Choices:**
   - **B: To be sure the contact will count for award programs**  
     - While signal reports are often part of the logging requirements for awards, the primary reason for exchanging them is not for award validation but to assess communication quality.
   - **C: To follow standard radiogram structure**  
     - Radiograms are specific message formats used in traffic handling, not general QSOs (contacts). Signal reports are not part of a radiogram structure.
   - **D: To allow each station to calibrate their frequency display**  
     - Signal reports do not provide information about frequency accuracy. Frequency calibration is typically done using other methods, such as comparing with a known standard.

3. **Useful Information:**
   - Signal reports are often given in the RST format, where:
     - **R** = Readability (1-5)
     - **S** = Signal strength (1-9)
     - **T** = Tone (1-9, used in CW)
   - Example: An RST report of 599 indicates perfectly readable, strong signal, and perfect tone (for CW).

Understanding the purpose of signal reports helps operators make informed decisions to maintain effective communication.