🔍 Key Concepts

• What a collinear array antenna is used for in VHF marine radio systems • The difference between antenna types (yagi, collinear, phased array transducer) and radio internal components (filters) • How gain and radiation pattern relate to vertical vs horizontal stacking of antenna elements

💭 Think About

• Which option actually describes an antenna structure made of multiple elements in line with each other to increase gain? • Which choices are not antennas at all, but internal radio parts or completely different equipment? • Among the antenna options, which one is typically used on vessels for omnidirectional VHF coverage, rather than for narrow directional shore links or underwater sound?

✅ Before You Answer

• Identify which options are true antennas and which are not antennas • Among the antenna options, decide which is directional vs omnidirectional in the horizontal plane • Recall that a marine VHF collinear array is usually vertical, with elements stacked in line to increase gain without making the horizontal pattern narrow