Deep Dive: E9H07
The correct answer is B: Absorb signals from the reverse direction. The function of a Beverage antenna's termination resistor is to absorb signals from the reverse direction. The resistor terminates the antenna, preventing reflections and making it unidirectional. A Beverage antenna is a traveling-wave antenna. Without termination, it would be bidirectional. The termination resistor (at the far end) absorbs the wave traveling in the reverse direction, preventing it from reflecting back. This makes the antenna unidirectional - it receives well from the forward direction (toward the termination) but poorly from the reverse direction. The termination resistor must match the antenna's characteristic impedance (typically 400-600 ohms) to properly absorb the reverse wave. This unidirectional characteristic is what makes Beverage antennas excellent for receiving on noisy bands.
Why Other Answers Are Wrong
Option A: Incorrect. The termination doesn't increase front-to-side ratio. It creates unidirectionality (front-to-back), not specifically front-to-side improvement. Option C: Incorrect. The termination doesn't decrease SWR bandwidth - it actually helps maintain consistent SWR. The termination is for pattern control, not bandwidth. Option D: Incorrect. The termination doesn't eliminate harmonic reception. It controls directionality, not frequency response.
Exam Tip
Beverage termination function = Absorb reverse signals. Remember: A Beverage antenna's termination resistor absorbs signals from the reverse direction, making the antenna unidirectional and improving forward reception.
Memory Aid
**B**everage **T**ermination = **A**bsorb **R**everse (think 'BT = AR')
Real-World Example
Your Beverage antenna has a termination resistor at the far end. When a signal comes from the reverse direction (toward the feed point), the termination resistor absorbs it, preventing reflection. This makes your antenna unidirectional - it receives well from the forward direction (away from the feed point) but rejects signals from behind. This is why Beverages are excellent for receiving on noisy bands.
Source & Coverage
Question Pool: 2024-2028 Question Pool
Subelement: E9H
Reference: FCC Part 97.3
Key Concepts
Verified Content
Question from the official FCC Extra Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the E9H topic.