Ham Radio General Class Practice Test

Where should the radial wires of a ground-mounted vertical antenna system be placed?

1. As high as possible above the ground

2. Parallel to the antenna element

3. On the surface or buried a few inches below the ground

4. At the top of the antenna

The correct answer is: On the surface or buried a few inches below the ground

In a ground-mounted vertical antenna system, the radial wires play a crucial role in enhancing the performance of the antenna. Placing the radial wires on the surface or buried just a few inches below the ground ensures effective interaction with the ground and the electromagnetic field. This proximity to the earth allows the radials to effectively mimic the effect of a ground plane, which is essential for the antenna's radiation pattern and overall efficiency. When radials are placed on the ground or slightly below it, they can create a more uniform ground reflection, which helps in radiating the signal more efficiently. This configuration reduces ground loss and improves the antenna's performance across different frequencies. It is also easier to maintain and install compared to running them at higher elevations or parallel to the antenna, which would not utilize the ground's conductivity effectively. Positioning radials high above the ground or parallel to the vertical antenna element can lead to suboptimal performance because they would not be able to create the necessary ground plane effect that enhances the antenna's efficiency. Placing them at the top of the antenna serves no practical purpose in terms of grounding effects and can create issues with radiation patterns and impedance matching.