Ham Radio General Class Practice Test

What happens when the feed point of a quad antenna is changed from the center of either horizontal wire to the center of either vertical wire?

1. The polarization of the radiated signal changes from horizontal to vertical

2. The polarization of the radiated signal changes from vertical to horizontal

3. The direction of the main lobe is reversed

4. The radiated signal changes to an omnidirectional pattern

The correct answer is: The polarization of the radiated signal changes from horizontal to vertical

When the feed point of a quad antenna is moved from the center of either horizontal wire to the center of either vertical wire, the polarization of the radiated signal changes from horizontal to vertical. In a quad antenna, the orientation of the elements plays a crucial role in determining the polarization of the emitted radio waves. When you feed the antenna at a horizontal element, the polarization is horizontal, meaning the electric field of the radiated signal oscillates in a horizontal plane relative to the ground. Conversely, when feeding the antenna at a vertical element, the emitted signal's electric field oscillates vertically, which means the polarization is vertical. This fundamental principle of antenna design explains the behavior of the antenna under the specified changes in the feed point, and it's important for operators to understand the implications of polarization when designing their setups for effective communication.