*Question T7B01:
What can you do if you are told your FM handheld or mobile transceiver is over-deviating?*  

*Correct Answer is  D: Talk farther away from the microphone*  

### AI Response: (may contain errors)  

When your FM handheld or mobile transceiver is over-deviating, it means that the modulation is exceeding the allowed deviation limits, which can cause distortion and interfere with other communications. 

### Correct Answer: Talk farther away from the microphone

- **Explanation**: 
  - By talking farther away from the microphone, you reduce the audio level being picked up. This decreases the modulation level, helping to keep the deviation within acceptable limits. 
  - FM deviation is directly related to the audio input level; lower audio input results in lower deviation.

### Why the Other Choices are Incorrect:

- **A: Talk louder into the microphone**  
  - This would increase the audio level, leading to even greater deviation and worsening the over-deviation problem.

- **B: Let the transceiver cool off**  
  - Cooling the transceiver does not address the issue of over-deviation. Over-deviation is related to audio input levels, not the temperature of the device.

- **C: Change to a higher power level**  
  - Increasing power does not affect the modulation deviation. It may increase the signal strength but will not solve the over-deviation issue.

### Useful Rules of Thumb:

- **FM Deviation**: The deviation of an FM signal is determined by the audio input level and the modulation sensitivity of the transmitter. 
- **Modulation Index**: The modulation index ($\beta$) can be calculated as:
  
  $$\beta = \frac{f_d}{f_m}$$

  where:
  - $f_d$ = frequency deviation
  - $f_m$ = modulating frequency

- **Keep Audio Levels in Check**: Always monitor your audio levels to ensure they are within the recommended range for your transceiver to avoid over-deviation. 

By understanding these concepts, you can effectively manage your FM transmission quality.