Which of the following describes a Zepp antenna?
The correct answer is B: An end-fed half-wavelength dipole. A Zepp antenna is an end-fed half-wavelength dipole. The name comes from its use on Zeppelin airships, where one end was fed and the other end was free.
A Zepp antenna is essentially a half-wave dipole fed at one end instead of the center. One end connects to the feed line, and the other end is left open (not connected). This creates a different current distribution and impedance compared to a center-fed dipole. The end-fed configuration was convenient on airships where the antenna could hang from the ship. Zepp antennas typically require a matching network or tuner because the end-fed configuration creates different impedance than center-fed dipoles.
Exam Tip
Zepp antenna = End-fed half-wave dipole. Remember: A Zepp antenna is an end-fed half-wavelength dipole - one end is fed, the other end is open (free).
Memory Aid
"**Z**epp = **E**nd-**F**ed **H**alf-**W**ave (think 'Z = EFHW')"
Real-World Application
You build a Zepp antenna. You string up a half-wavelength wire. One end connects to your feed line, and the other end is left open (not connected to anything). This end-fed configuration was used on Zeppelin airships, hence the name. You'll likely need a tuner because the end-fed impedance is different from a center-fed dipole.
FCC Part 97.3Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. A Zepp isn't a horizontal array with phasing lines. It's a simple end-fed half-wave dipole.
Option C: Incorrect. A Zepp isn't specifically for satellite communications. It's a general-purpose HF antenna.
Option D: Incorrect. A Zepp isn't a vertical array. It's typically a horizontal wire antenna.
题目解析
The correct answer is B: An end-fed half-wavelength dipole. A Zepp antenna is an end-fed half-wavelength dipole. The name comes from its use on Zeppelin airships, where one end was fed and the other end was free. A Zepp antenna is essentially a half-wave dipole fed at one end instead of the center. One end connects to the feed line, and the other end is left open (not connected). This creates a different current distribution and impedance compared to a center-fed dipole. The end-fed configuration was convenient on airships where the antenna could hang from the ship. Zepp antennas typically require a matching network or tuner because the end-fed configuration creates different impedance than center-fed dipoles.
考试技巧
Zepp antenna = End-fed half-wave dipole. Remember: A Zepp antenna is an end-fed half-wavelength dipole - one end is fed, the other end is open (free).
记忆口诀
**Z**epp = **E**nd-**F**ed **H**alf-**W**ave (think 'Z = EFHW')
实际应用示例
You build a Zepp antenna. You string up a half-wavelength wire. One end connects to your feed line, and the other end is left open (not connected to anything). This end-fed configuration was used on Zeppelin airships, hence the name. You'll likely need a tuner because the end-fed impedance is different from a center-fed dipole.
错误选项分析
Option A: Incorrect. A Zepp isn't a horizontal array with phasing lines. It's a simple end-fed half-wave dipole. Option C: Incorrect. A Zepp isn't specifically for satellite communications. It's a general-purpose HF antenna. Option D: Incorrect. A Zepp isn't a vertical array. It's typically a horizontal wire antenna.
知识点
Zepp antenna, End-fed dipole, Half-wavelength, Antenna feeding
Verified Content
Question from official FCC Extra Class question pool. Explanation reviewed by licensed amateur radio operators.