*Question E9H01:
When constructing a Beverage antenna, which of the following factors should be included in the design to achieve good performance at the desired frequency?*  

*Correct Answer is  D: It should be at least one wavelength long*  

### AI Response: (may contain errors)  

A Beverage antenna is a type of long-wire antenna primarily used for receiving low-frequency signals, such as those in the HF bands. Here's why the correct answer is D, and why the other choices are incorrect:

1. **Correct Answer: D - It should be at least one wavelength long**
   - A Beverage antenna is designed to be a long-wire antenna, typically several wavelengths long, to achieve good directivity and gain at low angles of radiation. For effective performance, it should be at least one wavelength long at the desired frequency. This length helps in capturing the signal effectively and providing the desired directional characteristics.

2. **Why the other choices are incorrect:**
   - **A: Its overall length must not exceed 1/4 wavelength**
     - This is incorrect because a Beverage antenna needs to be much longer than 1/4 wavelength to function properly. A length of 1/4 wavelength would not provide the necessary directivity and gain characteristics that make the Beverage antenna effective.
   
   - **B: It must be mounted more than 1 wavelength above ground**
     - This is incorrect because a Beverage antenna is typically mounted close to the ground, often just a few feet above it. The proximity to the ground is part of its design, as it uses the ground to help with its directional properties.
   
   - **C: It should be configured as a four-sided loop**
     - This is incorrect because a Beverage antenna is not a loop antenna. It is a long, straight wire. Loop antennas are a different type of antenna with different design and performance characteristics.

In summary, the key to a Beverage antenna's performance is its length, which should be at least one wavelength at the desired frequency to ensure good directivity and reception.