T9A – Antennas: vertical and horizontal polarization, concept of antenna gain, definition and types of beam antennas, antenna loading, common portable and mobile antennas, relationships between resonant length and frequency, dipole pattern 

- [[T9A01]] (C)
What is a beam antenna? #card
	- A. An antenna built from aluminum I-beams
	- B. An omnidirectional antenna invented by Clarence Beam
	- C. An antenna that concentrates signals in one direction
	- D. An antenna that reverses the phase of received signals

- [[T9A02]] (A)
Which of the following describes a type of antenna loading? #card
	- A. Electrically lengthening by inserting inductors in radiating elements
	- B. Inserting a resistor in the radiating portion of the antenna to make it resonant
	- C. Installing a spring in the base of a mobile vertical antenna to make it more flexible
	- D. Strengthening the radiating elements of a beam antenna to better resist wind damage

- [[T9A03]] (B)
Which of the following describes a simple dipole oriented parallel to Earth's surface? #card
	- A. A ground-wave antenna
	- B. A horizontally polarized antenna
	- C. A travelling-wave antenna
	- D. A vertically polarized antenna 

- [[T9A04]] (A)
What is a disadvantage of the short, flexible antenna supplied with most handheld radio transceivers, compared to a full-sized quarter-wave antenna? #card
	- A. It has low efficiency
	- B. It transmits only circularly polarized signals
	- C. It is mechanically fragile
	- D. All these choices are correct

- [[T9A05]] (C)
Which of the following increases the resonant frequency of a dipole antenna? #card
	- A. Lengthening it
	- B. Inserting coils in series with radiating wires
	- C. Shortening it
	- D. Adding capacitive loading to the ends of the radiating wires

- [[T9A06]] (D)
Which of the following types of antenna offers the greatest gain? #card
	- A. 5/8 wave vertical 
	- B. Isotropic
	- C. J pole
	- D. Yagi 

- [[T9A07]] (A)
What is a disadvantage of using a handheld VHF transceiver with a flexible antenna inside a vehicle? #card
	- A. Signal strength is reduced due to the shielding effect of the vehicle
	- B. The bandwidth of the antenna will decrease, increasing SWR
	- C. The SWR might decrease, decreasing the signal strength
	- D. All these choices are correct

- [[T9A08]] (C)
What is the approximate length, in inches, of a quarter-wavelength vertical antenna for 146 MHz? #card
	- A. 112
	- B. 50
	- C. 19
	- D. 12

- [[T9A09]] (C)
What is the approximate length, in inches, of a half-wavelength 6 meter dipole antenna? #card
	- A. 6
	- B. 50
	- C. 112
	- D. 236

- [[T9A10]] (D)
In which direction does a half-wave dipole antenna radiate the strongest signal? #card
	- A. Equally in all directions
	- B. Off the ends of the antenna
	- C. In the direction of the feed line
	- D. Broadside to the antenna

- [[T9A11]] (C)
What is antenna gain? #card
	- A. The additional power that is added to the transmitter power
	- B. The additional power that is required in the antenna when transmitting on a higher frequency
	- C. The increase in signal strength in a specified direction compared to a reference antenna
	- D. The increase in impedance on receive or transmit compared to a reference antenna

- [[T9A12]] (A)
What is an advantage of a 5/8 wavelength whip antenna for VHF or UHF mobile service? #card
	- A. It has more gain than a 1/4-wavelength antenna
	- B. It radiates at a very high angle
	- C. It eliminates distortion caused by reflected signals
	- D. It has 10 times the power gain of a 1/4 wavelength whip