*Question E1A09:
[97.313(l)] Except in some parts of Alaska, what is the maximum power permitted on the 630-meter band?*  

*Correct Answer is  D: 5 watts EIRP (equivalent isotropic radiated power)*  

### AI Response: (may contain errors)  

The correct answer to the question about the maximum power permitted on the 630-meter band is **D: 5 watts EIRP (equivalent isotropic radiated power)**. 

### Explanation of the Correct Answer:
- The Federal Communications Commission (FCC) regulations specify that the maximum power output for the 630-meter band is limited to 5 watts EIRP. This means that the total power radiated by the antenna, taking into account its gain, should not exceed this limit. 

### Why the Other Choices are Incorrect:
- **A: 50 watts PEP**: This option exceeds the regulatory limit for the 630-meter band. The FCC does not allow this level of power on this band.
  
- **B: 100 watts PEP**: Similar to option A, this power level is also above the maximum allowed for the 630-meter band, making it incorrect.
  
- **C: 1 watt EIRP**: While this is a valid power level for some other bands, it is below the maximum allowed for the 630-meter band, which is 5 watts EIRP. Therefore, it is not the correct answer.

### Useful Formulas and Rules of Thumb:
- **EIRP Calculation**: The equivalent isotropic radiated power can be calculated using the formula:
  
  $$EIRP = P_T \times G_A$$
  
  where:
  - $P_T$ = transmitter power in watts
  - $G_A$ = antenna gain (linear)

- **Understanding EIRP**: EIRP takes into account both the transmitter power and the gain of the antenna, providing a measure of the effective power radiated in a specific direction.

This information is crucial for understanding power limits and ensuring compliance with FCC regulations while operating on the 630-meter band.