*Question E1F03:
[97.315] Under what circumstances may a dealer sell an external RF power amplifier capable of operation below 144 MHz if it has not been granted FCC certification?*  

*Correct Answer is  D: The amplifier is constructed or modified by an amateur radio operator for use at an amateur station*  

### AI Response: (may contain errors)  

In the context of FCC regulations, the sale of external RF power amplifiers capable of operation below 144 MHz is tightly controlled to prevent interference and ensure compliance with technical standards. Here's a breakdown of the correct answer and why the other choices are incorrect:

1. **Correct Answer: D**  
   - **Explanation**: The FCC allows an external RF power amplifier to be sold without certification if it is constructed or modified by an amateur radio operator for use at an amateur station. This exception is made because amateur radio operators are expected to have the technical knowledge to ensure that their equipment operates within legal limits and does not cause harmful interference.

2. **Incorrect Choices**:
   - **A: Gain is less than 23 dB when driven by power of 10 watts or less**  
     - **Explanation**: The gain and input power specifications do not exempt an amplifier from needing FCC certification. The rules focus on the construction and intended use by amateur operators, not on specific technical parameters like gain.
   
   - **B: The equipment dealer assembled it from a kit**  
     - **Explanation**: Simply assembling an amplifier from a kit does not exempt it from needing certification. The key factor is the involvement of an amateur radio operator in the construction or modification process for personal use.
   
   - **C: It was manufactured and certificated in a country which has a reciprocal certification agreement with the FCC**  
     - **Explanation**: Even if an amplifier is certified in another country, it must still meet FCC certification requirements to be sold in the United States. Reciprocal agreements do not automatically grant certification for equipment operating below 144 MHz.

**Key Rule**:  
- The FCC regulation [97.315] specifically allows for the sale of uncertified amplifiers if they are constructed or modified by amateur radio operators for use at their own stations. This is an exception to the general requirement for certification, recognizing the technical expertise of licensed amateurs.