Multiple Choice
Identify the
choice that best completes the statement or answers the question.
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1.
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T3C01 Why are direct (not via a repeater) UHF
signals rarely heard from stations outside your local coverage area?
a. | They are too weak to go very far | c. | UHF signals are usually not reflected by the
ionosphere | b. | FCC regulations
prohibit them from going more than 50 miles | d. | UHF signals are
absorbed by the ionospheric D layer |
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2.
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T3C03 What is a characteristic of VHF signals
received via auroral reflection?
a. | Signals from distances of 10,000 or more miles are
common | c. | These types of signals occur only during winter
nighttime hours | b. | The signals
exhibit rapid fluctuations of strength and often sound distorted | d. | These types of
signals are generally strongest when your antenna Is aimed
west |
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3.
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T3C04 Which of the following propagation types is
most commonly associated with occasional strong over-the-horizon signals on the 10, 6, and 2-meter
bands?
a. | Backscatter | c. | D
layer absorption | b. | Sporadic
E | d. | Gray-line propagation |
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4.
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T3C05 Which of the following effects might
cause radio signals to be heard despite obstructions between the transmitting and receiving
stations?
a. | Knife-edge diffraction | c. | Quantum tunneling | b. | Faraday
rotation | d. | Doppler shift |
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5.
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T3C06 What mode is responsible for allowing
over-the-horizon VHF and UHF communications to ranges of approximately 300 miles on a regular
basis?
a. | Tropospheric ducting | c. | F2 layer refraction | b. | D layer
refraction | d. | Faraday rotation |
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6.
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T3C07 What band is best suited for
communicating via meteor scatter?
a. | 10 meter bend | c. | 2
meter band | b. | 6 meter
band | d. | 70 centimeter band |
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7.
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T3C08 What causes tropospheric
ducting?
a. | Discharges of lightning during electrical
storms | c. | Updrafts from hurricanes and
tornadoes | b. | Sunspots and solar flares | d. | Temperature
inversions in the atmosphere |
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8.
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T3C09 What is generally the best time for
long-distance 10-meter band propagation via the F layer?
a. | From dawn to shortly after sunset during periods of high
sunspot activity | c. | From dawn to shortly after sunset
during periods of low sunspot activity | b. | From shortly after
sunset to dawn during periods of high sunspot activity | d. | From shortly after
sunset to dawn during periods of low sunspot activity |
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9.
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T3C10 Which of the following bands may
provide long distance communications during the peak of the sunspot cycle?
a. | 6 or 10 meter bands | c. | 70 centimeter or 1.25 meter bands | b. | 23 centimeter band | d. | All of these
choices are correct |
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10.
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T3C11 Why do VHF and UHF radio signals usually travel somewhat farther than
the visual line of sight distance between two stations?
a. | Radio signals move somewhat faster than the speed of
light | c. | The Earth seems less curved to radio waves than to
light | b. | Radio waves are not blocked by dust
particles | d. | Radio waves are blocked by dust
particles |
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11.
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T3C02 Which of the following is an advantage of HF
vs VHF and higher frequencies?
a. | HF antennas are generally smaller | c. | Long distance ionospheric propagation is far more common on
HF | b. | HF accommodates wider bandwidth
signals | d. | There is less atmospheric interference (static) on
HF |
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