T9A Wavelength vs. antenna length; 1/2
wavelength dipole and 1/4
wavelength
vertical antennas; multiband antennas
T9A01
@N9A01
How do
you calculate the length (in feet) of a half-wavelength dipole
antenna?
A. Divide 150 by the antenna's operating
frequency (in MHz) [150/f(in
MHz)]
B. Divide 234 by the antenna's operating
frequency (in MHz) [234/f
(in
MHz)]
C. Divide 300 by the antenna's operating
frequency (in MHz) [300/f
(in
MHz)]
D. Divide 468 by the antenna's operating
frequency (in MHz) [468/f
(in
MHz)]
T9A02
@N9A02
How do
you calculate the length (in feet) of a quarter-wavelength
vertical
antenna?
A. Divide 150 by the antenna's operating
frequency (in MHz) [150/f
(in
MHz)]
B. Divide 234 by the antenna's operating
frequency (in MHz) [234/f
(in
MHz)]
C. Divide 300 by the antenna's operating
frequency (in MHz) [300/f
(in
MHz)]
D. Divide 468 by the antenna's operating
frequency (in MHz) [468/f
(in
MHz)]
T9A03
New
How
long should you make a quarter-wavelength vertical antenna for 440
MHz
(measured to the nearest inch)?
A. 12 inches
B. 9 inches
C. 6 inches
D. 3 inches
T9A04
New
How
long should you make a quarter-wavelength vertical antenna for
28.450
MHz (measured to the nearest foot)?
A. 8 ft
B. 12 ft
C. 16 ft
D. 24 ft
T9A05
New
How
long should you make a quarter-wavelength vertical antenna for 146
MHz
(measured to the nearest inch)?
A. 112 inches
B. 50 inches
C. 19 inches
D. 12 inches
T9A06
@N9A08
If an
antenna is made longer, what happens to its resonant frequency?
A. It decreases
B. It increases
C. It stays the same
D. It disappears
T9A07
@N9A09
If an
antenna is made shorter, what happens to its resonant frequency?
A. It decreases
B. It increases
C. It stays the same
D. It disappears
T9A08
@N9A10
How
could you decrease the resonant frequency of a dipole antenna?
A. Lengthen the antenna
B. Shorten the antenna
C. Use less feed line
D. Use a smaller size feed line
T9A09
@N9A11
How
could you increase the resonant frequency of a dipole antenna?
A. Lengthen the antenna
B. Shorten the antenna
C. Use more feed line
D. Use a larger size feed line
T9A10
@N9A12
What is
one advantage to using a multiband antenna?
A. You can operate on several bands with a
single feed line
B. Multiband antennas always have high gain
C. You can transmit on several frequencies
simultaneously
D. Multiband antennas offer poor harmonic suppression
T9A11
@N9A13
What is
one disadvantage to using a multiband antenna?
A. It must always be used with a balun
B. It will always have low gain
C. It cannot handle high power
D. It can radiate unwanted harmonics