SUBELEMENT T9 – Antennas and feed lines - [2 Exam Questions - 2 Groups]

Question 1

T9A01 (C)

What is a beam antenna?

Answer 1

C. An antenna that concentrates signals in one direction

Question 2

T9A02 (A)

Which of the following describes a type of antenna loading?

Answer 2

A. Inserting an inductor in the radiating portion of the antenna to make it electrically longer

Question 3

T9A03 (B)

Which of the following describes a simple dipole oriented parallel to the Earth’s surface?

Answer 3

B. A horizontally polarized antenna

Question 4

T9A04 (A)
What is a disadvantage of the “rubber duck” antenna supplied with most handheld radio transceivers when compared to a full-sized quarter-wave antenna?

Answer 4

A. It does not transmit or receive as effectively

Question 5

T9A05 (C)

How would you change a dipole antenna to make it resonant on a higher frequency?

Answer 5

C. Shorten it

Question 6

T9A06 (C)

What type of antennas are the quad, Yagi, and dish?

Answer 6

C. Directional antennas

Question 7

T9A07 (A)

What is a disadvantage of using a handheld VHF transceiver, with its integral antenna, inside a vehicle?

Answer 7

A. Signals might not propagate well due to the shielding effect of the vehicle

Question 8

T9A08 (C)

What is the approximate length, in inches, of a quarter-wavelength vertical antenna for 146 MHz?

Answer 8

C. 19

Question 9

T9A09 (C)

What is the approximate length, in inches, of a half-wavelength 6 meter dipole antenna?

Answer 9

C. 112

Question 10

T9A10 (C)

In which direction does a half-wave dipole antenna radiate the strongest signal?

Answer 10

C. Broadside to the antenna

Question 11

T9A11 (C)

What is the gain of an antenna?

Answer 11

C. The increase in signal strength in a specified direction compared to a reference antenna

Question 12

T9A12 (A)

What is an advantage of using a properly mounted 5/8 wavelength antenna for VHF or UHF mobile service?

Answer 12

A. It has a lower radiation angle and more gain than a 1/4 wavelength antenna

Question 13

T9B01 (B)

Why is it important to have low SWR when using coaxial cable feed line?

Answer 13

B. To reduce signal loss

Question 14

T9B02 (B)

What is the impedance of most coaxial cables used in amateur radio installations?

Answer 14

B. 50 ohms

Question 15

T9B03 (A)

Why is coaxial cable the most common feed line selected for amateur radio antenna systems?

Answer 15

A. It is easy to use and requires few special installation considerations

Question 16

T9B04 (A)

What is the major function of an antenna tuner (antenna coupler)?

Answer 16

A. It matches the antenna system impedance to the transceiver’s output impedance

Question 17

T9B05 (D)

In general, what happens as the frequency of a signal passing through coaxial cable is increased?

Answer 17

D. The loss increases

Question 18

T9B06 (B)

Which of the following connectors is most suitable for frequencies above 400 MHz?

Answer 18

B. A Type N connector

Question 19

T9B07 (C)

Which of the following is true of PL-259 type coax connectors?

Answer 19

C. They are commonly used at HF frequencies

Question 20

T9B08 (A)

Why should coax connectors exposed to the weather be sealed against water intrusion?

Answer 20

A. To prevent an increase in feed line loss

Question 21

T9B09 (B)

What can cause erratic changes in SWR readings?

Answer 21

B. A loose connection in an antenna or a feed line

Question 22

T9B10 (C)

What is the electrical difference between RG-58 and RG-8 coaxial cable?

Answer 22

C. RG-8 cable has less loss at a given frequency

Question 23

T9B11 (C)

Which of the following types of feed line has the lowest loss at VHF and UHF?

Answer 23

C. Air-insulated hard line