*Question G1B09:
[97.203(d)] On what HF frequencies are automatically controlled beacons permitted?*  

*Correct Answer is  D: 28.20 MHz to 28.30 MHz*  

### AI Response: (may contain errors)  

In the context of amateur radio, automatically controlled beacons are stations that transmit signals without direct human intervention. These beacons are used for various purposes, such as propagation studies.

1. **Correct Answer: D: 28.20 MHz to 28.30 MHz**

   - **Explanation**: The FCC rules specifically allocate the frequency range of 28.20 MHz to 28.30 MHz in the 10-meter band for automatically controlled beacons. This allocation is intended to facilitate propagation studies and other beacon-related activities without causing interference to other amateur operations.

2. **Why the Other Choices are Incorrect**:

   - **A: On any frequency if power is less than 1 watt**  
     This is incorrect because the power level does not determine the frequency allocation for automatically controlled beacons. The FCC rules specify certain frequency ranges regardless of power levels.

   - **B: On any frequency if transmissions are in Morse code**  
     While Morse code is a common mode for beacon transmissions, it does not grant permission to operate on any frequency. The frequency allocation is determined by FCC regulations, not the mode of transmission.

   - **C: 21.08 MHz to 21.09 MHz**  
     This frequency range is not allocated for automatically controlled beacons. The correct allocation for such beacons is in the 28.20 MHz to 28.30 MHz range.

3. **Useful Rules of Thumb**:

   - Always refer to the FCC Part 97 rules for specific frequency allocations and operating conditions for different types of amateur radio operations.
   - Remember that specific frequency ranges are designated for certain types of operations to prevent interference and ensure efficient use of the spectrum.

Understanding these allocations helps ensure compliance with regulations and promotes effective use of the amateur radio bands.