*Question E9H06:
What indicates the correct value of terminating resistance for a Beverage antenna?*  

*Correct Answer is  D: Minimum variation in SWR over the desired frequency range*  

### AI Response: (may contain errors)  

A Beverage antenna is a type of long-wire antenna used primarily for receiving low-frequency signals. It is known for its directional properties and ability to reduce noise. The terminating resistance plays a crucial role in its performance.

### Correct Answer: D - Minimum variation in SWR over the desired frequency range

1. **Why the correct answer is correct:**
   - The terminating resistance of a Beverage antenna is chosen to ensure that the antenna has a consistent impedance across the desired frequency range. This consistency minimizes the variation in the Standing Wave Ratio (SWR), which is a measure of how well the antenna is matched to the transmission line. A low and stable SWR indicates efficient power transfer and reduced reflections, which is desirable for optimal antenna performance.

2. **Why the other choices are incorrect:**
   - **A: Maximum feed point DC resistance at the center of the desired frequency range**
     - This choice is incorrect because the DC resistance at the feed point is not directly related to the antenna's performance across a frequency range. The focus should be on impedance matching rather than DC resistance.
   
   - **B: Minimum low-angle front-to-back ratio at the design frequency**
     - This choice is incorrect because the front-to-back ratio is a measure of the antenna's directional properties, not its impedance matching. The terminating resistance primarily affects impedance matching, not the directional pattern.
   
   - **C: Maximum DC current in the terminating resistor**
     - This choice is incorrect because the DC current in the terminating resistor is not a relevant factor for determining the correct terminating resistance. The focus should be on achieving a stable SWR, not on current levels.

3. **Useful formulas or rules of thumb:**
   - The SWR is calculated as:
     $$ \text{SWR} = \frac{1 + |\Gamma|}{1 - |\Gamma|} $$
     where $\Gamma$ is the reflection coefficient, which depends on the impedance mismatch between the antenna and the transmission line.
   - A terminating resistance that minimizes SWR variation ensures that $\Gamma$ remains small across the frequency range, indicating good impedance matching.

By focusing on minimizing SWR variation, you ensure that the Beverage antenna operates efficiently over the desired frequency range, which is crucial for its performance as a receiving antenna.