T9A

Question 1

T9A01 (C)
What is a beam antenna?

1 An antenna built from aluminum I-beams
2 An omnidirectional antenna invented by Clarence
Beam
3 An antenna that concentrates signals in one direction
4 An antenna that reverses the phase of received signals

Answer 1

3 An antenna that concentrates signals in one direction

Question 2

T9A02 (A)
Which of the following describes a type of antenna loading?

1 Inserting an inductor in the radiating portion of the
antenna to make it electrically longer
2 Inserting a resistor in the radiating portion of the
antenna to make it resonant
3 Installing a spring in the base of a mobile vertical
antenna to make it more flexible
4 Strengthening the radiating elements of a beam
antenna to better resist wind damage

Answer 2

1 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?

1 A ground-wave antenna
2 A horizontally polarized antenna
3 A rhombic antenna
4 A vertically polarized antenna

Answer 3

2 A horizontally polarized antenna

Question 4

T9A05 (C)
How would you change a dipole antenna to make it resonant on a higher frequency?

1 Lengthen it
2 Insert coils in series with radiating wires
3 Shorten it
4 Add capacitive loading to the ends of the radiating
wires

Answer 4

3 Shorten it

Question 5

T9A08 (C)
What is the approximate length, in inches, of a quarter-wavelength vertical antenna for 146 MHz?

1 112
2 50
3 19
4 12

Answer 5

3 19

Question 6

T9A09 (C)
What is the approximate length, in inches, of a half-wavelength 6 meter dipole antenna?

1 6
2 50
3 112
4 236

Answer 6

3 112

Question 7

T9A10 (C)
In which direction does a half-wave dipole antenna radiate the strongest signal?

1 Equally in all directions
2 Off the ends of the antenna
3 Broadside to the antenna
4 In the direction of the feed line

Answer 7

3 Broadside to the antenna

Question 8

T9A11 (C)
What is the gain of an antenna?

1 The additional power that is added to the transmitter
power
2 The additional power that is lost in the antenna when
transmitting on a higher frequency
3 The increase in signal strength in a specified direction
compared to a reference antenna
4 The increase in impedance on receive or transmit
compared to a reference antenna

Answer 8

3 The increase in signal strength in a specified direction

compared to a reference antenna

Question 9

T9A12 (A)
What is an advantage of using a properly mounted 5/8 wavelength antenna for VHF or UHF mobile service?

1 It has a lower radiation angle and more gain than a 1/4
wavelength antenna
2 It has very high angle radiation for better
communicating through a repeater
3 It eliminates distortion caused by reflected signals
4 It has 10 times the power gain of a 1/4 wavelength
design

Answer 9

1 It has a lower radiation angle and more gain than a 1/4

wavelength antenna