Technician Practice Test T9 – Antennas and Feed Lines
Antenna types, polarization, gain, coax cable, connectors and SWR. Tap an answer to check it.
Score: 0 / 0 (15)
Question 1
What is a beam antenna?
A beam antenna concentrates signals in one direction.
Question 2
Which of the following describes a type of antenna loading?
Loading coils (inductors) make an antenna electrically longer than its physical length.
Question 3
How is the polarization of an antenna described?
Antenna polarization is the orientation of the electric field.
Question 4
What is a disadvantage of a handheld radio transceiver’s short flexible antenna compared to a full-sized quarter-wave antenna?
The short flexible "rubber duck" antenna on a handheld has low efficiency compared with a full quarter-wave.
Question 5
Which of the following increases the resonant frequency of a dipole antenna?
A shorter dipole resonates at a higher frequency.
Question 6
Which of the following types of antennas offers the greatest gain?
A Yagi is a beam antenna and has the most gain of these choices.
Question 7
What is a potential drawback of using a handheld VHF transceiver inside a vehicle that lacks an externally mounted antenna?
The metal body of a vehicle shields the signal, so a handheld inside without an outside antenna works poorly.
Question 8
Why is a 19-inch-long vertical antenna often used on 2 meters?
A quarter wave at 146 MHz is about 19 inches (234 ÷ 146 MHz ≈ 1.6 feet).
Question 9
What is an advantage of a 5/8-wavelength whip antenna for VHF or UHF mobile service compared to a 1/4-wave antenna?
A 5/8-wave whip has more gain than a 1/4-wave whip.
Question 10
In which direction does a half-wave dipole antenna radiate the strongest signal?
A half-wave dipole radiates most strongly broadside (at right angles) to the wire.
Question 11
What is antenna gain?
Gain is the increase in signal strength in a given direction compared with a reference antenna.
Question 12
Which of the following connectors should be carefully taped for weather protection when used outdoors?
PL-259, BNC and Type N connectors all need weather protection outdoors, because water ruins coax.
Question 13
What is the most common impedance of coaxial cables used in amateur radio?
Most amateur coax has an impedance of 50 ohms.
Question 14
Why is coaxial cable the most common feed line for amateur radio antenna systems?
Coax is easy to use and needs few special installation steps, so it is the most common feed line.
Question 15
What is the major function of an antenna tuner (antenna coupler)?
An antenna tuner matches the antenna system impedance to the transmitter's output impedance.
Get all 409 questions in the app
Full mock exams with one question from each group like test day, a readiness score for every subelement, mistake review and formula cards. No ads.
▶ Get it on Google PlayWant more T9 · Antennas questions?
These are the first 15 of 23 T9 · Antennas questions. The app has all of them, plus full mock exams that pick one question from each group like the real test.
Get all 409 questions in the app
Full mock exams with one question from each group like test day, a readiness score for every subelement, mistake review and formula cards. No ads.
▶ Get it on Google PlayOfficial sources
The questions are the official public Technician pool. The rules come from FCC Part 97. Always check these sources for the current rules.