T9B Parasitic beam directional antennas;
polarization, impedance
matching
and SWR, feed lines, balanced vs. unbalanced (including
baluns)
T9B01
@T9A01
What is
a directional antenna?
A. An antenna that sends and receives radio
energy equally well in
all
directions
B. An antenna that cannot send and receive
radio energy by skywave or
skip
propagation
C. An antenna that sends and receives radio
energy mainly in one
direction
D. An antenna that uses a directional coupler
to measure power
transmitted
T9B02
@T9A02
How is
a Yagi antenna constructed?
A. Two or more straight, parallel elements are
fixed in line with
each
other
B. Two or more square or circular loops are
fixed in line with each
other
C. Two or more square or circular loops are
stacked inside each other
D. A straight element is fixed in the center of
three or more
elements
that angle toward the ground
T9B03
@T9A04
How
many directly driven elements do most parasitic beam antennas
have?
A. None
B. One
C. Two
D. Three
T9B04
@T9A05
What is
a parasitic beam antenna?
A. An antenna in which some elements obtain
their radio energy by
induction
or radiation from a driven element
B. An antenna in which wave traps are used to
magnetically couple the
elements
C. An antenna in which all elements are driven
by direct connection
to the
feed line
D. An antenna in which the driven element
obtains its radio energy by
induction
or radiation from director elements
T9B05
@T9A06
What
are the parasitic elements of a Yagi antenna?
A. The driven element and any reflectors
B. The director and the driven element
C. Only the reflectors (if any)
D. Any directors or any reflectors
T9B06
@T9A07
What is
a cubical quad antenna?
A. Four straight, parallel elements in line
with each other, each
approximately
1/2-electrical wavelength long
B. Two or more parallel four-sided wire loops,
each approximately
one-electrical
wavelength long
C. A vertical conductor 1/4-electrical
wavelength high, fed at the
bottom
D. A center-fed wire 1/2-electrical wavelength
long
T9B07
@T9A10
What
type of non-directional antenna is easy to make at home and works
well
outdoors?
A. A Yagi
B. A delta loop
C. A cubical quad
D. A ground plane
T9B08
@T9B06
What
electromagnetic-wave polarization does most man-made electrical
noise
have in the HF and VHF spectrum?
A. Horizontal
B. Left-hand circular
C. Right-hand circular
D. Vertical
T9B09
@T9B09
What
does standing-wave ratio mean?
A. The ratio of maximum to minimum inductances
on a feed line
B. The ratio of maximum to minimum capacitances
on a feed line
C. The ratio of maximum to minimum impedances
on a feed line
D. The ratio of maximum to minimum voltages on
a feed line
T9B10
@N9C12
Where
would you install a balun to feed a dipole antenna with 50-ohm
coaxial
cable?
A. Between the coaxial cable and the antenna
B. Between the transmitter and the coaxial
cable
C. Between the antenna and the ground
D. Between the coaxial cable and the ground
T9B11
@N9C02
Why
does coaxial cable make a good antenna feed line?
A. You can make it at home, and its impedance
matches most amateur
antennas
B. It is weatherproof, and it can be used near
metal objects
C. It is weatherproof, and its impedance is
higher than that of most
amateur
antennas
D. It can be used near metal objects, and its
impedance is higher
than
that of most amateur antennas