*Question G0A06:
[97.13(c)(2), 1.1307(1)(b)(3)(i)] What must you do if your station fails to meet the FCC RF exposure exemption criteria?*  

*Correct Answer is  A: Perform an RF exposure evaluation in accordance with FCC OET Bulletin 65*  

### AI Response: (may contain errors)  

To understand the requirements when your station fails to meet the FCC RF exposure exemption criteria, let's break down the correct answer and the other options.

### Correct Answer: A
**Perform an RF exposure evaluation in accordance with FCC OET Bulletin 65.**

- **Explanation**: If your station does not meet the exemption criteria, you are required to assess the RF exposure levels to ensure they comply with the FCC's safety standards. FCC OET Bulletin 65 provides guidelines on how to conduct this evaluation, including methods for calculating exposure levels and determining compliance.

### Why the Other Choices are Incorrect:
- **B: Contact the FCC for permission to transmit**  
  - **Explanation**: While you must comply with FCC regulations, simply contacting the FCC for permission is not the correct action. The FCC does not grant permission based on RF exposure; instead, you must evaluate and mitigate exposure risks.

- **C: Perform an RF exposure evaluation in accordance with World Meteorological Organization guidelines**  
  - **Explanation**: The World Meteorological Organization (WMO) does not set RF exposure standards for amateur radio. The FCC's guidelines (OET Bulletin 65) are the relevant authority for RF exposure evaluations in the U.S.

- **D: Use an FCC-approved band-pass filter**  
  - **Explanation**: While band-pass filters can help reduce unwanted emissions and improve signal quality, they do not directly address RF exposure compliance. Using a filter does not substitute for the required evaluation of RF exposure levels.

### Useful Rules of Thumb:
- **RF Exposure Evaluation**: When conducting an RF exposure evaluation, consider the following:
  - Calculate the power density at various distances from the antenna.
  - Use the formula for power density ($S$) at a distance ($d$) from a point source:
  
  $$
  S = \frac{P_T \times G}{4 \pi d^2}
  $$

  where:
  - $S$ = power density in watts per square meter (W/m²)
  - $P_T$ = transmitter power in watts
  - $G$ = gain of the antenna (linear)
  - $d$ = distance from the antenna in meters

- **Compliance Thresholds**: Familiarize yourself with the FCC's limits for RF exposure, which vary based on frequency and exposure duration.

By understanding these points, you will be better prepared for questions related to RF exposure and compliance on the Extra Class exam.