*Question G4A11:
Why should the ALC system be inactive when transmitting AFSK data signals?*  

*Correct Answer is  B: The ALC action distorts the signal*  

### AI Response: (may contain errors)  

The correct answer to the question is B: The ALC action distorts the signal. Here's a breakdown of why this is the case, along with explanations for the other choices:

### Explanation of the Correct Answer (B)
- **Automatic Level Control (ALC)** is designed to prevent over-modulation by automatically adjusting the transmitter's output power based on the input signal level.
- When transmitting AFSK (Audio Frequency Shift Keying) data signals, the rapid changes in signal levels can cause the ALC to react too slowly or too aggressively, leading to distortion of the signal.
- Distortion can result in loss of data integrity, making the transmission less effective or even unreadable.

### Explanation of Incorrect Choices
- **Choice A: ALC will invert the modulation of the AFSK mode**
  - This is incorrect because ALC does not invert the modulation. Instead, it adjusts the power level to prevent distortion. The modulation itself remains intact; it's the signal quality that may be affected.

- **Choice C: When using digital modes, too much ALC activity can cause the transmitter to overheat**
  - While excessive ALC activity can lead to inefficiencies, overheating is not a direct consequence of ALC operation during digital modes. The primary concern is signal distortion, not thermal management.

- **Choice D: All these choices are correct**
  - Since choices A and C are incorrect, this choice cannot be correct. The only accurate statement is that ALC action distorts the signal.

### Summary
- **Key Point**: ALC should be inactive during AFSK transmissions to avoid signal distortion, which is critical for maintaining data integrity.
- **Rule of Thumb**: For digital modes, ensure that the ALC is disabled to allow for clean, undistorted signal transmission.

By understanding these points, you can better prepare for questions related to ALC and its impact on digital signal transmission in the Extra Class exam.