Practical answer: A Yagi uses a driven element with parasitic reflector and director elements to produce forward gain and rear rejection along its boom axis.
What changes on the air
Element length, spacing, boom interaction, feed match, height, polarization, and surroundings work together. Changing one dimension can move impedance and pattern at the same time.
Plan the installation
- Identify the reflector and director ends.
- Aim the boom axis at the path.
- Rotate the whole antenna for required polarization.
- Keep nearby conductors out of the element plane.
Common mistakes
- Aiming the side of the elements at the station.
- Changing factory match before checking cable.
- Using HF connector habits to ignore UHF loss.
Technical boundary
General VHF/UHF antenna and transmission-line practice. Use the current product guide for exact dimensions, ratings, connectors, mounting, and supported configurations.
