Propagation
Surface mode - Ground Wave
Direct mode - Line of Sight
Ionospheric mode - Sky wave
Tropospheric mode - Scattering, Ducting, Delay
Surface mode - Ground Wave
Direct mode - Line of Sight
Ionospheric mode - Sky wave
Tropospheric mode - Scattering, Ducting, Delay
Basic Qualification Question Bank for Amateur Radio Operator Certificate Examinations 12 June, 2014
Propagation
Surface mode - Ground Wave
(C)
B-007-001-006 That portion of the radiation which is directly affected by the surface of the Earth is called:
A ionospheric wave
B inverted wave
C ground wave
D tropospheric wave
(D)
B-007-001-007 At lower HF frequencies, radiocommunication out to 200 km is made possible by:
A troposphere
B skip wave
C ionosphere
D ground wave
(A)
B-007-001-008 The distance travelled by ground waves:
A is less at higher frequencies
B depends on the maximum usable frequency
C is more at higher frequencies
D is the same for all frequencies
Direct mode - Line of Sight
(B)
B-007-001-001 What type of propagation usually occurs from one hand-held VHF transceiver to another nearby?
A Auroral propagation
B Line-of-sight propagation
C Tunnel propagation
D Skywave propagation
(C)
B-007-001-004 How are VHF signals propagated within the range of the visible horizon?
A By plane wave
B By geometric wave
C By direct wave
D By sky wave
Ionospheric mode - Sky wave
(A)
B-007-001-002 How does the range of sky-wave propagation compare to ground-wave propagation?
A It is much longer
B It is much shorter
C It is about the same
D It depends on the weather
(B)
B-007-001-009 The radio wave which follows a path from the transmitter to the ionosphere and back to Earth is known correctly as the:
A skip wave
B ionospheric wave
C F layer
D surface wave
(C)
B-007-001-010 Reception of high frequency(HF) radio waves beyond 4000 km is generally made possible by:
A skip wave
B surface wave
C ionospheric wave
D ground wave
(D)
B-007-002-001 What causes the ionosphere to form?
A Lightning ionizing the outer atmosphere
B Release of fluorocarbons into the atmosphere
C Temperature changes ionizing the outer atmosphere
D Solar radiation ionizing the outer atmosphere
(B)
B-007-002-002 What type of solar radiation is most responsible for ionization in the outer atmosphere?
A Thermal
B Ultraviolet
C Microwave
D Ionized particles
(A)
B-007-002-003 Which ionospheric region is closest to the Earth?
A The D region
B The E region
C The F region
D The A region
(B)
B-007-002-004 Which region of the ionosphere is the least useful for long distance radio-wave propagation?
A The E region
B The D region
C The F2 region
D The F1 region
(D)
B-007-002-005 What two sub-regions of ionosphere exist only in the daytime?
A Troposphere and stratosphere
B Electrostatic and electromagnetic
C D and E
D F1 and F2
(B)
B-007-002-006 When is the ionosphere most ionized?
A Dusk
B Midday
C Dawn
D Midnight
(B)
B-007-002-007 When is the ionosphere least ionized?
A Shortly before midnight
B Shortly before dawn
C Just after noon
D Just after dusk
(D)
B-007-002-008 Why is the F2 region mainly responsible for the longest distance radio-wave propagation?
A Because it exists only at night
B Because it is the lowest ionospheric region
C Because it does not absorb radio waves as much as other ionospheric regions
D Because it is the highest ionospheric region
(D)
B-007-002-009 What is the main reason the 160, 80 and 40 metre amateur bands tend to be useful only for short-distance communications during daylight hours?
A Because of auroral propagation
B Because of magnetic flux
C Because of a lack of activity
D Because of D-region absorption
(D)
B-007-002-010 During the day, one of the ionospheric layers splits into two parts called:
A D1 and D2
B E1 and E2
C A and B
D F1 and F2
(B)
B-007-002-011 The position of the E layer in the ionosphere is:
A above the F layer
B below the F layer
C below the D layer
D sporadic
(A)
B-007-003-001 What is a skip zone?
A An area which is too far away for ground-wave propagation, but too close for sky-wave propagation
B An area which is too far away for ground-wave or sky-wave propagation
C An area covered by sky-wave propagation
D An area covered by ground-wave propagation
(A)
B-007-003-002 What is the maximum distance along the Earth's surface that is normally covered in one hop using the F2 region?
A 4000km(2500 miles)
B None; the F2 region does not support radio-wave propagation
C 2000 km(1250 miles)
D 300 km(190 miles)
(C)
B-007-003-003 What is the maximum distance along the Earth's surface that is normally covered in one hop using the E region?
A 4000 km(2500 miles)
B None; the E region does not support radio-wave propagation
C 2000 km(1250 miles)
D 300 km(190 miles)
(C)
B-007-003-004 Skip zone is:
A a zone between any two refracted waves
B a zone between the antenna and the return of the first refracted wave
C a zone between the end of the ground wave and the point where the first refracted wave returns to Earth
D a zone of silence caused by lost sky waves
(A)
B-007-003-005 The distance to Europe from your location is approximately 5000 km. What sort of propagation is the most likely to be involved?
A Multihop
B Sporadic "E"
C Back scatter
D Tropospheric scatter
(B)
B-007-003-006 For radio signals, the skip distance is determined by the:
A type of transmitting antenna used
B height of the ionosphere and the angle of radiation
C power fed to the power amplifier
D angle of radiation
(D)
B-007-003-007 The distance from the transmitter to the nearest point where the sky wave returns to the Earth is called the:
A skip zone
B angle of radiation
C maximum usable frequency
D skip distance
(C)
B-007-003-008 Skip distance is the:
A the minimum distance reached by a ground-wave signal
B the maximum distance a signal will travel by both a ground wave and reflected wave
C the minimum distance reached by a signal after one reflection by the ionosphere
D the maximum distance reached by a signal after one reflection by the ionosphere
(D)
B-007-003-009 Skip distance is a term associated with signals from the ionosphere. Skip effects are due to:
A selective fading of local signals
B high gain antennas being used
C local cloud cover
D reflection and refraction from the ionosphere
(A)
B-007-003-010 The skip distance of a sky wave will be greatest when the:
A angle between the ground and the radiation is smallest
B polarization is vertical
C ionosphere is most densely ionized
D signal given out is strongest
(B)
B-007-003-011 If the height of the reflecting layer of the ionosphere increases, the skip distance of a high frequency(HF) transmission:
A decreases
B becomes greater
C stays the same
D varies regularly
(D)
B-007-004-001 What effect does the D region of the ionosphere have on lower frequency HF signals in the daytime?
A It bends the radio waves out into space
B It refracts the radio waves back to Earth
C It has little or no effect on 80-metre radio waves
D It absorbs the signals
(B)
B-007-001-005 Skywave is another name for:
A inverted wave
B ionospheric wave
C tropospheric wave
D ground wave
(D)
B-007-001-003 When a signal is returned to Earth by the ionosphere, what is this called?
A Tropospheric propagation
B Ground-wave propagation
C Earth-Moon-Earth propagation
D Sky-wave propagation
(C)
B-007-004-002 What causes distant AM broadcast and 160 metre ham band stations not to be heard during daytime hours??
A The splitting of the F region
B The weather below the ionosphere
C The ionization of the D region
D The presence of ionized clouds in the E region
(C)
B-007-004-003 Two or more parts of the radio wave follow different paths during propagation and this may result in phase differences at the receiver. This "change" at the receiver is called:
A absorption
B skip
C fading
D baffling
(D)
B-007-004-004 A change or variation in signal strength at the antenna, caused by differences in path lengths, is called:
A absorption
B fluctuation
C path loss
D fading
(A)
B-007-004-005 When a transmitted radio signal reaches a station by a one-hop and two-hop skip path, small changes in the ionosphere can cause:
A variations in signal strength
B consistent fading of received signal
C consistently stronger signals
D a change in the ground-wave signal
(B)
B-007-004-006 The usual effect of ionospheric storms is to:
A increase the maximum usable frequency
B cause a fade-out of sky-wave signals
C produce extreme weather changes
D prevent communications by ground wave
(A)
B-007-004-007 On the VHF and UHF bands, polarization of the receiving antenna is very important in relation to the transmitting antenna, yet on HF bands it is relatively unimportant. Why is that so?
A The ionosphere can change the polarization of the signal from moment to moment
B The ground wave and the sky wave continually shift the polarization
C Anomalies in the Earth's magnetic field produce a profound effect on HF polarization but not on VHF & UHF frequencies
D Greater selectivity is possible with HF receivers making changes in polarization redundant
(A)
B-007-004-008 What causes selective fading?
A Phase differences between radio wave components of the same transmission, as experienced at the receiving station
B Small changes in beam heading at the receiving station
C Time differences between the receiving and transmitting stations
D Large changes in the height of the ionosphere at the receiving station ordinarily occurring shortly before sunrise and sunset
(D)
B-007-004-009 How does the bandwidth of a transmitted signal affect selective fading?
A It is the same for both wide and narrow bandwidths
B Only the receiver bandwidth determines the selective fading effect
C It is more pronounced at narrow bandwidths
D It is more pronounced at wide bandwidths
(C)
B-007-004-010 Polarization change often takes place on radio waves that are propagated over long distances. Which of these does not cause polarization change?
A Passage through magnetic fields(Faraday rotation)
B Refractions
C Parabolic interaction
D Reflections
(A)
B-007-004-011 Reflection of a SSB transmission from the ionosphere causes:
A little or no phase-shift distortion
B phase-shift distortion
C signal cancellation at the receiver
D a high-pitch squeal at the receiver
(A)
B-007-005-001 How do sunspots change the ionization of the atmosphere?
A The more sunspots there are, the greater the ionization
B The more sunspots there are, the less the ionization
C Unless there are sunspots, the ionization is zero
D They have no effect
(D)
B-007-005-002 How long is an average sunspot cycle?
A 17 years
B 5 years
C 7 years
D 11 years
(B)
B-007-005-003 What is solar-flux?
A The density of the sun's magnetic field
B The radio energy emitted by the sun
C A measure of the tilt of the Earth's ionosphere on the side toward the sun
D The number of sunspots on the side of the sun facing the Earth
(C)
B-007-005-004 What is the solar-flux index?
A A measure of solar activity that compares daily readings with results from the last six months
B A measure of solar activity that is taken annually
C A measure of solar activity that is taken at a specific frequency
D Another name for the American sunspot number
(A)
B-007-005-005 What influences all radiocommunication beyond ground-wave or line-of-sight ranges?
A Solar radiation
B The F2 region of the ionosphere
C The F1 region of the ionosphere
D Lunar tidal effects
(A)
B-007-005-006 Which two types of radiation from the sun influence propagation?
A Electromagnetic and particle emissions
B Subaudible and audio-frequency emissions
C Polar region and equatorial emissions
D Infrared and gamma-ray emissions
(C)
B-007-005-007 When sunspot numbers are high, how is propagation affected?
A Frequencies up to 100 MHz or higher are normally usable for long-distance communication
B High frequency radio signals become weak and distorted
C Frequencies up to 40 MHz or even higher become usable for long-distance communication
D High frequency radio signals are absorbed
(D)
B-007-005-008 All communication frequencies throughout the spectrum are affected in varying degrees by the:
A ionosphere
B aurora borealis
C atmospheric conditions
D sun
(A)
B-007-005-009 Average duration of a solar cycle is:
A 11 years
B 3 years
C 6 years
D 1 year
(D)
B-007-005-010 The ability of the ionosphere to reflect high frequency radio signals depends on:
A the power of the transmitted signal
B the receiver sensitivity
C upper atmosphere weather conditions
D the amount of solar radiation
(B)
B-007-005-011 HF radio propagation cycles have a period of approximately 11:
A centuries
B years
C months
D days
(C)
B-007-006-001 What happens to signals higher in frequency than the critical frequency?
A Their frequency is changed by the ionosphere to be below the maximum usable frequency
B They are reflected back to their source
C They pass through the ionosphere
D They are absorbed by the ionosphere
(D)
B-007-006-002 What causes the maximum usable frequency to vary?
A The temperature of the ionosphere
B The speed of the winds in the upper atmosphere
C The type of weather just below the ionosphere
D The amount of radiation received from the sun, mainly ultraviolet
(B)
B-007-006-003 What does maximum usable frequency mean?
A The lowest frequency signal that is most absorbed by the ionosphere
B The highest frequency signal that will reach its intended destination
C The lowest frequency signal that will reach its intended destination
D The highest frequency signal that is most absorbed by the ionosphere
(D)
B-007-006-004 What can be done at an amateur station to continue HF communications during a sudden ionospheric disturbance?
A Try the other sideband
B Try a different antenna polarization
C Try a different frequency shift
D Try a higher frequency band
(B)
B-007-006-005 What is one way to determine if the maximum usable frequency(MUF) is high enough to support 28 MHz propagation between your station and western Europe?
A Listen for WWVH time signals on 20 MHz
B Listen for signals from 10-metre beacon stations
C Listen for signals from 20-metre beacon stations
D Listen for signals from 39-metre broadcast stations
(B)
B-007-006-006 What usually happens to radio waves with frequencies below the maximum usable frequency(MUF) when they are sent into the ionosphere?
A They pass through the ionosphere
B They are bent back to the Earth
C They are changed to a frequency above the MUF
D They are completely absorbed by the ionosphere
(B)
B-007-006-007 At what point in the solar cycle does the 20-metre band usually support worldwide propagation during daylight hours?
A At the summer solstice
B At any point in the solar cycle
C Only at the minimum point of the solar cycle
D Only at the maximum point of the solar cycle
(A)
B-007-006-008 If we transmit a signal, the frequency of which is so high we no longer receive a reflection from the ionosphere, the signal frequency is above the:
A maximum usable frequency
B skip distance
C speed of light
D sunspot frequency
(B)
B-007-006-009 Communication on the 80 metre band is generally most difficult during:
A daytime in winter
B daytime in summer
C evening in winter
D evening in summer
(D)
B-007-006-010 The optimum working frequency provides the best long range HF communication. Compared with the maximum usable frequency(MUF), it is usually:
A double the MUF
B half the MUF
C slightly higher
D slightly lower
(D)
B-007-006-011 During summer daytime, which bands are the most difficult for communications beyond ground wave?
A 40 metres
B 30 metres
C 20 metres
D 160 and 80 metres
Tropospheric mode - Scattering, Ducting, Delay
(D)
B-007-007-002 What effect does tropospheric bending have on 2-metre radio waves?
A It causes them to travel shorter distances
B It garbles the signal
C It reverses the sideband of the signal
D It lets you contact stations farther away
(D)
B-007-007-003 What causes tropospheric ducting of radio waves?
A Lightning between the transmitting and receiving stations
B An aurora to the north
C A very low pressure area
D A temperature inversion
(C)
B-007-007-004 That portion of the radiation kept close to the Earth's surface due to bending in the atmosphere is called the:
A ground wave
B ionospheric wave
C tropospheric wave
D inverted wave
(D)
B-007-007-005 What is a sporadic-E condition?
A Partial tropospheric ducting at E-region height
B Variations in E-region height caused by sunspot variations
C A brief decrease in VHF signals caused by sunspot variations
D Patches of dense ionization at E-region height
(B)
B-007-007-006 On which amateur frequency band is the extended-distance propagation effect of sporadic-E most often observed?
A 2 metres
B 6 metres
C 160 metres
D 20 metres
(D)
B-007-007-007 In the northern hemisphere, in which direction should a directional antenna be pointed to take maximum advantage of auroral propagation?
A East
B West
C South
D North
(B)
B-007-007-008 Where in the ionosphere does auroral activity occur?
A At D-region height
B At E-region height
C At F-region height
D In the equatorial band
(A)
B-007-007-009 Which emission mode is best for auroral propagation?
A CW
B RTTY
C FM
D SSB
(A)
B-007-007-010 Excluding enhanced propagation modes, what is the approximate range of normal VHF tropospheric propagation?
A 800 km(500 miles)
B 2400 km(1500 miles)
C 3200 km(2000 miles)
D 1600 km(1000 miles)
(C)
B-007-007-011 What effect is responsible for propagating a VHF signal over 800 km(500 miles)?
A D-region absorption
B Moon bounce(EME) Earth - Moon - Earth
C Tropospheric ducting
D Faraday rotation
(C)
B-007-007-001 Which ionospheric region most affects sky-wave propagation on the 6 metre band?
A The F1 region
B The D region
C The E region
D The F2 region
(B)
B-007-008-001 What kind of unusual HF propagation allows weak signals from the skip zone to be heard occasionally?
A Ground-wave
B Scatter-mode
C Sky-wave with low radiation angle
D Ducting
(C)
B-007-008-002 If you receive a weak, distorted signal from a distance, and close to the maximum usable frequency, what type of propagation is probably occurring?
A Line-of-sight
B Ducting
C Scatter
D Ground-wave
(B)
B-007-008-003 What is a characteristic of HF scatter signals?
A High intelligibility
B Rapid flutter or hollow sounding distortion
C Reversed modulation
D Reversed sidebands
(A)
B-007-008-004 What makes HF scatter signals often sound distorted?
A Energy scattered into the skip zone through several radio-wave paths
B Auroral activity and changes in the Earth's magnetic field
C Propagation through ground waves that absorb much of the signal
D The state of the E-region at the point of refraction
(D)
B-007-008-005 Why are HF scatter signals usually weak?
A Propagation through ground waves absorbs most of the signal energy
B The F region of the ionosphere absorbs most of the signal energy
C Auroral activity absorbs most of the signal energy
D Only a small part of the signal energy is scattered into the skip zone
(A)
B-007-008-006 What type of propagation may allow a weak signal to be heard at a distance too far for ground-wave propagation but too near for normal sky-wave propagation?
A Scatter
B Short-path skip
C Sporadic-E skip
D Ground wave
(A)
B-007-008-007 On the HF bands, when is scatter propagation most likely involved?
A When weak and distorted signals near or above the maximum usable frequency for normal propagation can be heard over unusual paths
B When the sunspot cycle is at a minimum and D-region absorption is high
C At night
D When the F1 and F2 regions are combined
(C)
B-007-008-008 Which of the following is not a scatter mode?
A Tropospheric scatter
B Ionospheric scatter
C Absorption scatter
D Meteor scatter
(D)
B-007-008-009 Meteor scatter is most effective on what band?
A 40 metres
B 15 metres
C 160 metres
D 6 metres
(B)
B-007-008-010 Which of the following is not a scatter mode?
A Forward scatter
B Inverted scatter
C Side scatter
D Back scatter
(C)
B-007-008-011 In which frequency range is meteor scatter most effective for extended-range communication?
A 3 - 10 MHz
B 100 - 300 MHz
C 30 - 100 MHz
D 10 - 30 MHz
Propagation
Surface mode - Ground Wave
(C)
B-007-001-006 That portion of the radiation which is directly affected by the surface of the Earth is called:
A ionospheric wave
B inverted wave
C ground wave
D tropospheric wave
(D)
B-007-001-007 At lower HF frequencies, radiocommunication out to 200 km is made possible by:
A troposphere
B skip wave
C ionosphere
D ground wave
(A)
B-007-001-008 The distance travelled by ground waves:
A is less at higher frequencies
B depends on the maximum usable frequency
C is more at higher frequencies
D is the same for all frequencies
Direct mode - Line of Sight
(B)
B-007-001-001 What type of propagation usually occurs from one hand-held VHF transceiver to another nearby?
A Auroral propagation
B Line-of-sight propagation
C Tunnel propagation
D Skywave propagation
(C)
B-007-001-004 How are VHF signals propagated within the range of the visible horizon?
A By plane wave
B By geometric wave
C By direct wave
D By sky wave
Ionospheric mode - Sky wave
(A)
B-007-001-002 How does the range of sky-wave propagation compare to ground-wave propagation?
A It is much longer
B It is much shorter
C It is about the same
D It depends on the weather
(B)
B-007-001-009 The radio wave which follows a path from the transmitter to the ionosphere and back to Earth is known correctly as the:
A skip wave
B ionospheric wave
C F layer
D surface wave
(C)
B-007-001-010 Reception of high frequency(HF) radio waves beyond 4000 km is generally made possible by:
A skip wave
B surface wave
C ionospheric wave
D ground wave
(D)
B-007-002-001 What causes the ionosphere to form?
A Lightning ionizing the outer atmosphere
B Release of fluorocarbons into the atmosphere
C Temperature changes ionizing the outer atmosphere
D Solar radiation ionizing the outer atmosphere
(B)
B-007-002-002 What type of solar radiation is most responsible for ionization in the outer atmosphere?
A Thermal
B Ultraviolet
C Microwave
D Ionized particles
(A)
B-007-002-003 Which ionospheric region is closest to the Earth?
A The D region
B The E region
C The F region
D The A region
(B)
B-007-002-004 Which region of the ionosphere is the least useful for long distance radio-wave propagation?
A The E region
B The D region
C The F2 region
D The F1 region
(D)
B-007-002-005 What two sub-regions of ionosphere exist only in the daytime?
A Troposphere and stratosphere
B Electrostatic and electromagnetic
C D and E
D F1 and F2
(B)
B-007-002-006 When is the ionosphere most ionized?
A Dusk
B Midday
C Dawn
D Midnight
(B)
B-007-002-007 When is the ionosphere least ionized?
A Shortly before midnight
B Shortly before dawn
C Just after noon
D Just after dusk
(D)
B-007-002-008 Why is the F2 region mainly responsible for the longest distance radio-wave propagation?
A Because it exists only at night
B Because it is the lowest ionospheric region
C Because it does not absorb radio waves as much as other ionospheric regions
D Because it is the highest ionospheric region
(D)
B-007-002-009 What is the main reason the 160, 80 and 40 metre amateur bands tend to be useful only for short-distance communications during daylight hours?
A Because of auroral propagation
B Because of magnetic flux
C Because of a lack of activity
D Because of D-region absorption
(D)
B-007-002-010 During the day, one of the ionospheric layers splits into two parts called:
A D1 and D2
B E1 and E2
C A and B
D F1 and F2
(B)
B-007-002-011 The position of the E layer in the ionosphere is:
A above the F layer
B below the F layer
C below the D layer
D sporadic
(A)
B-007-003-001 What is a skip zone?
A An area which is too far away for ground-wave propagation, but too close for sky-wave propagation
B An area which is too far away for ground-wave or sky-wave propagation
C An area covered by sky-wave propagation
D An area covered by ground-wave propagation
(A)
B-007-003-002 What is the maximum distance along the Earth's surface that is normally covered in one hop using the F2 region?
A 4000km(2500 miles)
B None; the F2 region does not support radio-wave propagation
C 2000 km(1250 miles)
D 300 km(190 miles)
(C)
B-007-003-003 What is the maximum distance along the Earth's surface that is normally covered in one hop using the E region?
A 4000 km(2500 miles)
B None; the E region does not support radio-wave propagation
C 2000 km(1250 miles)
D 300 km(190 miles)
(C)
B-007-003-004 Skip zone is:
A a zone between any two refracted waves
B a zone between the antenna and the return of the first refracted wave
C a zone between the end of the ground wave and the point where the first refracted wave returns to Earth
D a zone of silence caused by lost sky waves
(A)
B-007-003-005 The distance to Europe from your location is approximately 5000 km. What sort of propagation is the most likely to be involved?
A Multihop
B Sporadic "E"
C Back scatter
D Tropospheric scatter
(B)
B-007-003-006 For radio signals, the skip distance is determined by the:
A type of transmitting antenna used
B height of the ionosphere and the angle of radiation
C power fed to the power amplifier
D angle of radiation
(D)
B-007-003-007 The distance from the transmitter to the nearest point where the sky wave returns to the Earth is called the:
A skip zone
B angle of radiation
C maximum usable frequency
D skip distance
(C)
B-007-003-008 Skip distance is the:
A the minimum distance reached by a ground-wave signal
B the maximum distance a signal will travel by both a ground wave and reflected wave
C the minimum distance reached by a signal after one reflection by the ionosphere
D the maximum distance reached by a signal after one reflection by the ionosphere
(D)
B-007-003-009 Skip distance is a term associated with signals from the ionosphere. Skip effects are due to:
A selective fading of local signals
B high gain antennas being used
C local cloud cover
D reflection and refraction from the ionosphere
(A)
B-007-003-010 The skip distance of a sky wave will be greatest when the:
A angle between the ground and the radiation is smallest
B polarization is vertical
C ionosphere is most densely ionized
D signal given out is strongest
(B)
B-007-003-011 If the height of the reflecting layer of the ionosphere increases, the skip distance of a high frequency(HF) transmission:
A decreases
B becomes greater
C stays the same
D varies regularly
(D)
B-007-004-001 What effect does the D region of the ionosphere have on lower frequency HF signals in the daytime?
A It bends the radio waves out into space
B It refracts the radio waves back to Earth
C It has little or no effect on 80-metre radio waves
D It absorbs the signals
(B)
B-007-001-005 Skywave is another name for:
A inverted wave
B ionospheric wave
C tropospheric wave
D ground wave
(D)
B-007-001-003 When a signal is returned to Earth by the ionosphere, what is this called?
A Tropospheric propagation
B Ground-wave propagation
C Earth-Moon-Earth propagation
D Sky-wave propagation
(C)
B-007-004-002 What causes distant AM broadcast and 160 metre ham band stations not to be heard during daytime hours??
A The splitting of the F region
B The weather below the ionosphere
C The ionization of the D region
D The presence of ionized clouds in the E region
(C)
B-007-004-003 Two or more parts of the radio wave follow different paths during propagation and this may result in phase differences at the receiver. This "change" at the receiver is called:
A absorption
B skip
C fading
D baffling
(D)
B-007-004-004 A change or variation in signal strength at the antenna, caused by differences in path lengths, is called:
A absorption
B fluctuation
C path loss
D fading
(A)
B-007-004-005 When a transmitted radio signal reaches a station by a one-hop and two-hop skip path, small changes in the ionosphere can cause:
A variations in signal strength
B consistent fading of received signal
C consistently stronger signals
D a change in the ground-wave signal
(B)
B-007-004-006 The usual effect of ionospheric storms is to:
A increase the maximum usable frequency
B cause a fade-out of sky-wave signals
C produce extreme weather changes
D prevent communications by ground wave
(A)
B-007-004-007 On the VHF and UHF bands, polarization of the receiving antenna is very important in relation to the transmitting antenna, yet on HF bands it is relatively unimportant. Why is that so?
A The ionosphere can change the polarization of the signal from moment to moment
B The ground wave and the sky wave continually shift the polarization
C Anomalies in the Earth's magnetic field produce a profound effect on HF polarization but not on VHF & UHF frequencies
D Greater selectivity is possible with HF receivers making changes in polarization redundant
(A)
B-007-004-008 What causes selective fading?
A Phase differences between radio wave components of the same transmission, as experienced at the receiving station
B Small changes in beam heading at the receiving station
C Time differences between the receiving and transmitting stations
D Large changes in the height of the ionosphere at the receiving station ordinarily occurring shortly before sunrise and sunset
(D)
B-007-004-009 How does the bandwidth of a transmitted signal affect selective fading?
A It is the same for both wide and narrow bandwidths
B Only the receiver bandwidth determines the selective fading effect
C It is more pronounced at narrow bandwidths
D It is more pronounced at wide bandwidths
(C)
B-007-004-010 Polarization change often takes place on radio waves that are propagated over long distances. Which of these does not cause polarization change?
A Passage through magnetic fields(Faraday rotation)
B Refractions
C Parabolic interaction
D Reflections
(A)
B-007-004-011 Reflection of a SSB transmission from the ionosphere causes:
A little or no phase-shift distortion
B phase-shift distortion
C signal cancellation at the receiver
D a high-pitch squeal at the receiver
(A)
B-007-005-001 How do sunspots change the ionization of the atmosphere?
A The more sunspots there are, the greater the ionization
B The more sunspots there are, the less the ionization
C Unless there are sunspots, the ionization is zero
D They have no effect
(D)
B-007-005-002 How long is an average sunspot cycle?
A 17 years
B 5 years
C 7 years
D 11 years
(B)
B-007-005-003 What is solar-flux?
A The density of the sun's magnetic field
B The radio energy emitted by the sun
C A measure of the tilt of the Earth's ionosphere on the side toward the sun
D The number of sunspots on the side of the sun facing the Earth
(C)
B-007-005-004 What is the solar-flux index?
A A measure of solar activity that compares daily readings with results from the last six months
B A measure of solar activity that is taken annually
C A measure of solar activity that is taken at a specific frequency
D Another name for the American sunspot number
(A)
B-007-005-005 What influences all radiocommunication beyond ground-wave or line-of-sight ranges?
A Solar radiation
B The F2 region of the ionosphere
C The F1 region of the ionosphere
D Lunar tidal effects
(A)
B-007-005-006 Which two types of radiation from the sun influence propagation?
A Electromagnetic and particle emissions
B Subaudible and audio-frequency emissions
C Polar region and equatorial emissions
D Infrared and gamma-ray emissions
(C)
B-007-005-007 When sunspot numbers are high, how is propagation affected?
A Frequencies up to 100 MHz or higher are normally usable for long-distance communication
B High frequency radio signals become weak and distorted
C Frequencies up to 40 MHz or even higher become usable for long-distance communication
D High frequency radio signals are absorbed
(D)
B-007-005-008 All communication frequencies throughout the spectrum are affected in varying degrees by the:
A ionosphere
B aurora borealis
C atmospheric conditions
D sun
(A)
B-007-005-009 Average duration of a solar cycle is:
A 11 years
B 3 years
C 6 years
D 1 year
(D)
B-007-005-010 The ability of the ionosphere to reflect high frequency radio signals depends on:
A the power of the transmitted signal
B the receiver sensitivity
C upper atmosphere weather conditions
D the amount of solar radiation
(B)
B-007-005-011 HF radio propagation cycles have a period of approximately 11:
A centuries
B years
C months
D days
(C)
B-007-006-001 What happens to signals higher in frequency than the critical frequency?
A Their frequency is changed by the ionosphere to be below the maximum usable frequency
B They are reflected back to their source
C They pass through the ionosphere
D They are absorbed by the ionosphere
(D)
B-007-006-002 What causes the maximum usable frequency to vary?
A The temperature of the ionosphere
B The speed of the winds in the upper atmosphere
C The type of weather just below the ionosphere
D The amount of radiation received from the sun, mainly ultraviolet
(B)
B-007-006-003 What does maximum usable frequency mean?
A The lowest frequency signal that is most absorbed by the ionosphere
B The highest frequency signal that will reach its intended destination
C The lowest frequency signal that will reach its intended destination
D The highest frequency signal that is most absorbed by the ionosphere
(D)
B-007-006-004 What can be done at an amateur station to continue HF communications during a sudden ionospheric disturbance?
A Try the other sideband
B Try a different antenna polarization
C Try a different frequency shift
D Try a higher frequency band
(B)
B-007-006-005 What is one way to determine if the maximum usable frequency(MUF) is high enough to support 28 MHz propagation between your station and western Europe?
A Listen for WWVH time signals on 20 MHz
B Listen for signals from 10-metre beacon stations
C Listen for signals from 20-metre beacon stations
D Listen for signals from 39-metre broadcast stations
(B)
B-007-006-006 What usually happens to radio waves with frequencies below the maximum usable frequency(MUF) when they are sent into the ionosphere?
A They pass through the ionosphere
B They are bent back to the Earth
C They are changed to a frequency above the MUF
D They are completely absorbed by the ionosphere
(B)
B-007-006-007 At what point in the solar cycle does the 20-metre band usually support worldwide propagation during daylight hours?
A At the summer solstice
B At any point in the solar cycle
C Only at the minimum point of the solar cycle
D Only at the maximum point of the solar cycle
(A)
B-007-006-008 If we transmit a signal, the frequency of which is so high we no longer receive a reflection from the ionosphere, the signal frequency is above the:
A maximum usable frequency
B skip distance
C speed of light
D sunspot frequency
(B)
B-007-006-009 Communication on the 80 metre band is generally most difficult during:
A daytime in winter
B daytime in summer
C evening in winter
D evening in summer
(D)
B-007-006-010 The optimum working frequency provides the best long range HF communication. Compared with the maximum usable frequency(MUF), it is usually:
A double the MUF
B half the MUF
C slightly higher
D slightly lower
(D)
B-007-006-011 During summer daytime, which bands are the most difficult for communications beyond ground wave?
A 40 metres
B 30 metres
C 20 metres
D 160 and 80 metres
Tropospheric mode - Scattering, Ducting, Delay
(D)
B-007-007-002 What effect does tropospheric bending have on 2-metre radio waves?
A It causes them to travel shorter distances
B It garbles the signal
C It reverses the sideband of the signal
D It lets you contact stations farther away
(D)
B-007-007-003 What causes tropospheric ducting of radio waves?
A Lightning between the transmitting and receiving stations
B An aurora to the north
C A very low pressure area
D A temperature inversion
(C)
B-007-007-004 That portion of the radiation kept close to the Earth's surface due to bending in the atmosphere is called the:
A ground wave
B ionospheric wave
C tropospheric wave
D inverted wave
(D)
B-007-007-005 What is a sporadic-E condition?
A Partial tropospheric ducting at E-region height
B Variations in E-region height caused by sunspot variations
C A brief decrease in VHF signals caused by sunspot variations
D Patches of dense ionization at E-region height
(B)
B-007-007-006 On which amateur frequency band is the extended-distance propagation effect of sporadic-E most often observed?
A 2 metres
B 6 metres
C 160 metres
D 20 metres
(D)
B-007-007-007 In the northern hemisphere, in which direction should a directional antenna be pointed to take maximum advantage of auroral propagation?
A East
B West
C South
D North
(B)
B-007-007-008 Where in the ionosphere does auroral activity occur?
A At D-region height
B At E-region height
C At F-region height
D In the equatorial band
(A)
B-007-007-009 Which emission mode is best for auroral propagation?
A CW
B RTTY
C FM
D SSB
(A)
B-007-007-010 Excluding enhanced propagation modes, what is the approximate range of normal VHF tropospheric propagation?
A 800 km(500 miles)
B 2400 km(1500 miles)
C 3200 km(2000 miles)
D 1600 km(1000 miles)
(C)
B-007-007-011 What effect is responsible for propagating a VHF signal over 800 km(500 miles)?
A D-region absorption
B Moon bounce(EME) Earth - Moon - Earth
C Tropospheric ducting
D Faraday rotation
(C)
B-007-007-001 Which ionospheric region most affects sky-wave propagation on the 6 metre band?
A The F1 region
B The D region
C The E region
D The F2 region
(B)
B-007-008-001 What kind of unusual HF propagation allows weak signals from the skip zone to be heard occasionally?
A Ground-wave
B Scatter-mode
C Sky-wave with low radiation angle
D Ducting
(C)
B-007-008-002 If you receive a weak, distorted signal from a distance, and close to the maximum usable frequency, what type of propagation is probably occurring?
A Line-of-sight
B Ducting
C Scatter
D Ground-wave
(B)
B-007-008-003 What is a characteristic of HF scatter signals?
A High intelligibility
B Rapid flutter or hollow sounding distortion
C Reversed modulation
D Reversed sidebands
(A)
B-007-008-004 What makes HF scatter signals often sound distorted?
A Energy scattered into the skip zone through several radio-wave paths
B Auroral activity and changes in the Earth's magnetic field
C Propagation through ground waves that absorb much of the signal
D The state of the E-region at the point of refraction
(D)
B-007-008-005 Why are HF scatter signals usually weak?
A Propagation through ground waves absorbs most of the signal energy
B The F region of the ionosphere absorbs most of the signal energy
C Auroral activity absorbs most of the signal energy
D Only a small part of the signal energy is scattered into the skip zone
(A)
B-007-008-006 What type of propagation may allow a weak signal to be heard at a distance too far for ground-wave propagation but too near for normal sky-wave propagation?
A Scatter
B Short-path skip
C Sporadic-E skip
D Ground wave
(A)
B-007-008-007 On the HF bands, when is scatter propagation most likely involved?
A When weak and distorted signals near or above the maximum usable frequency for normal propagation can be heard over unusual paths
B When the sunspot cycle is at a minimum and D-region absorption is high
C At night
D When the F1 and F2 regions are combined
(C)
B-007-008-008 Which of the following is not a scatter mode?
A Tropospheric scatter
B Ionospheric scatter
C Absorption scatter
D Meteor scatter
(D)
B-007-008-009 Meteor scatter is most effective on what band?
A 40 metres
B 15 metres
C 160 metres
D 6 metres
(B)
B-007-008-010 Which of the following is not a scatter mode?
A Forward scatter
B Inverted scatter
C Side scatter
D Back scatter
(C)
B-007-008-011 In which frequency range is meteor scatter most effective for extended-range communication?
A 3 - 10 MHz
B 100 - 300 MHz
C 30 - 100 MHz
D 10 - 30 MHz
