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ISED - BASIC Radio Amateur > 007 - Radio Wave Propagation > Flashcards

007 - Radio Wave Propagation Flashcards

1
Q

B-007-001-001
What type of propagation usually occurs from one hand-held VHF transceiver to another nearby?

(a) Tunnel propagation
(b) Skywave propagation
(c) Auroral propagation
(d) Line-of-sight propagation

A

B-007-001-001
What type of propagation usually occurs from one hand-held VHF transceiver to another nearby?

(d) Line-of-sight propagation

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2
Q

B-007-001-002
How does the range of sky-wave propagation compare to ground-wave propagation?

(a) It is much shorter
(b) It is about the same
(c) It is much longer
(d) It depends on the weather

A

B-007-001-002
How does the range of sky-wave propagation compare to ground-wave propagation?

(c) It is much longer

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3
Q

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

A

B-007-001-003
When a signal is returned to Earth by the ionosphere, what is this called?

(d) Sky-wave propagation

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4
Q

B-007-001-004
How are VHF signals propagated within the range of the visible horizon?

(a) By sky wave
(b) By plane wave
(c) By geometric wave
(d) By direct wave

A

B-007-001-004
How are VHF signals propagated within the range of the visible horizon?

(d) By direct wave

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5
Q

B-007-001-005
Skywave is another name for:

(a) tropospheric wave
(b) ground wave
(c) inverted wave
(d) ionospheric wave

A

B-007-001-005
Skywave is another name for:

(d) ionospheric wave

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6
Q

B-007-001-006
That portion of the radiation which is directly affected by the surface of the Earth is called:

(a) ground wave
(b) tropospheric wave
(c) ionospheric wave
(d) inverted wave

A

B-007-001-006
That portion of the radiation which is directly affected by the surface of the Earth is called:

(a) ground wave

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7
Q

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-007-001-007
At lower HF frequencies, radiocommunication out to 200 km is made possible by:

(d) ground wave

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8
Q

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

A

B-007-001-008
The distance travelled by ground waves:

(a) is less at higher frequencies

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9
Q

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) ionospheric wave
(b) F layer
(c) surface wave
(d) skip wave

A

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) ionospheric wave

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10
Q

B-007-001-010
Reception of high frequency (HF) radio waves beyond 4000 km is generally made possible by:

(a) ground wave
(b) ionospheric wave
(c) skip wave
(d) surface wave

A

B-007-001-010
Reception of high frequency (HF) radio waves beyond 4000 km is generally made possible by:

(b) ionospheric wave

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11
Q

B-007-002-001
What causes the ionosphere to form?

(a) Solar radiation ionizing the outer atmosphere
(b) Lightning ionizing the outer atmosphere
(c) Release of fluorocarbons into the atmosphere
(d) Temperature changes ionizing the outer atmosphere

A

B-007-002-001
What causes the ionosphere to form?

(a) Solar radiation ionizing the outer atmosphere

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12
Q

B-007-002-002
What type of solar radiation is most responsible for ionization in the outer atmosphere?

(a) Microwave
(b) Ionized particles
(c) Ultraviolet
(d) Thermal

A

B-007-002-002
What type of solar radiation is most responsible for ionization in the outer atmosphere?

(c) Ultraviolet

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13
Q

B-007-002-003
Which ionospheric region is closest to the Earth?

(a) The E region
(b) The F region
(c) The A region
(d) The D region

A

B-007-002-003
Which ionospheric region is closest to the Earth?

(d) The D region

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14
Q

B-007-002-004
Which region of the ionosphere is the least useful for long distance radio-wave propagation?

(a) The F2 region
(b) The F1 region
(c) The E region
(d) The D region

A

B-007-002-004
Which region of the ionosphere is the least useful for long distance radio-wave propagation?

(d) The D region

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15
Q

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

A

B-007-002-005
What two sub-regions of ionosphere exist only in the daytime?

(d) F1 and F2

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16
Q

B-007-002-006
When is the ionosphere most ionized?

(a) Dawn
(b) Midday
(c) Midnight
(d) Dusk

A

B-007-002-006
When is the ionosphere most ionized?

(b) Midday

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17
Q

B-007-002-007
When is the ionosphere least ionized?

(a) Just after noon
(b) Just after dusk
(c) Shortly before midnight
(d) Shortly before dawn

A

B-007-002-007
When is the ionosphere least ionized?

(d) Shortly before dawn

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18
Q

B-007-002-008
Why is the F2 region mainly responsible for the longest distance radio-wave propagation?

(a) Because it is the highest ionospheric region
(b) Because it exists only at night
(c) Because it is the lowest ionospheric region
(d) Because it does not absorb radio waves as much as other ionospheric regions

A

B-007-002-008
Why is the F2 region mainly responsible for the longest distance radio-wave propagation?

(a) Because it is the highest ionospheric region

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19
Q

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 D-region absorption
(d) Because of a lack of activity

A

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?

(c) Because of D-region absorption

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20
Q

B-007-002-010
During the day, one of the ionospheric layers splits into two parts called:

(a) F1 and F2
(b) D1 and D2
(c) E1 and E2
(d) A and B

A

B-007-002-010
During the day, one of the ionospheric layers splits into two parts called:

(a) F1 and F2

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21
Q

B-007-002-011
The position of the E layer in the ionosphere is:

(a) below the D layer
(b) sporadic
(c) above the F layer
(d) below the F layer

A

B-007-002-011
The position of the E layer in the ionosphere is:

(d) below the F layer

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22
Q

B-007-003-001
What is a skip zone?

(a) An area which is too far away for ground-wave or sky-wave propagation
(b) An area which is too far away for ground-wave propagation, but too close for sky-wave propagation
(c) An area covered by sky-wave propagation
(d) An area covered by ground-wave propagation

A

B-007-003-001
What is a skip zone?

(b) An area which is too far away for ground-wave propagation, but too close for sky-wave propagation

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23
Q

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) None, the F2 region does not support radio-wave propagation
(b) 2000 km (1250 miles)
(c) 300 km (190 miles)
(d) 4000 km (2500 miles)

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?

(d) 4000 km (2500 miles)

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24
Q

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) 300 km (190 miles)
(b) 4000 km (2500 miles)
(c) 2000 km (1250 miles)
(d) None, the E region does not support radio-wave propagation

A

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?

(c) 2000 km (1250 miles)

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25
Q

B-007-003-004
Skip zone is:

(a) a zone between the end of the ground wave and the point where the first refracted wave returns to Earth
(b) a zone of silence caused by lost sky waves
(c) a zone between any two refracted waves
(d) a zone between the antenna and the return of the first refracted wave

A

B-007-003-004
Skip zone is:

(a) a zone between the end of the ground wave and the point where the first refracted wave returns to Earth

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26
Q

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) Sporadic “E
(b) Multihop
(c) Back scatter
(d) Tropospheric scatter

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?

(b) Multihop

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27
Q

B-007-003-006
For radio signals, the skip distance is determined by the:

(a) power fed to the power amplifier
(b) angle of radiation
(c) height of the ionosphere and the angle of radiation
(d) type of transmitting antenna used

A

B-007-003-006
For radio signals, the skip distance is determined by the:

(c) height of the ionosphere and the angle of radiation

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28
Q

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 distance
(b) skip zone
(c) angle of radiation
(d) maximum usable frequency

A

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 distance

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29
Q

B-007-003-008
Skip distance is the:

(a) the maximum distance reached by a signal after one reflection by the ionosphere
(b) the minimum distance reached by a ground-wave signal
(c) the maximum distance a signal will travel by both a ground wave and reflected wave
(d) the minimum distance reached by a signal after one reflection by the ionosphere

A

B-007-003-008
Skip distance is the:

(d) the minimum distance reached by a signal after one reflection by the ionosphere

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30
Q

B-007-003-009
Skip distance is a term associated with signals from the ionosphere. Skip effects are due to:

(a) reflection and refraction from the ionosphere
(b) selective fading of local signals
(c) high gain antennas being used
(d) local cloud cover

A

B-007-003-009
Skip distance is a term associated with signals from the ionosphere. Skip effects are due to:

(a) reflection and refraction from the ionosphere

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31
Q

B-007-003-010
The skip distance of a sky wave will be greatest when the:

(a) polarization is vertical
(b) ionosphere is most densely ionized
(c) signal given out is strongest
(d) angle between the ground and the radiation is smallest

A

B-007-003-010
The skip distance of a sky wave will be greatest when the:

(d) angle between the ground and the radiation is smallest

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32
Q

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) stays the same
(b) varies regularly
(c) decreases
(d) becomes greater

A

B-007-003-011
If the height of the reflecting layer of the ionosphere increases, the skip distance of a high frequency (HF) transmission:

(d) becomes greater

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33
Q

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

A

B-007-004-001
What effect does the D region of the ionosphere have on lower frequency HF signals in the daytime?

(d) It absorbs the signals

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34
Q

B-007-004-002
What causes distant AM broadcast and 160 metre ham band stations not to be heard during daytime hours?

(a) The presence of ionized clouds in the E region
(b) The ionization of the D region
(c) The splitting of the F region
(d) The weather below the ionosphere

A

B-007-004-002
What causes distant AM broadcast and 160 metre ham band stations not to be heard during daytime hours?

(b) The ionization of the D region

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35
Q

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) baffling
(b) fading
(c) absorption
(d) skip

A

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:

(b) fading

36
Q

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) fading
(d) path loss

A

B-007-004-004
A change or variation in signal strength at the antenna, caused by differences in path lengths, is called:

(c) fading

37
Q

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

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

38
Q

B-007-004-006
The usual effect of ionospheric storms is to:

(a) cause a fade-out of sky-wave signals
(b) produce extreme weather changes
(c) prevent communications by ground wave
(d) increase the maximum usable frequency

A

B-007-004-006
The usual effect of ionospheric storms is to:

(a) cause a fade-out of sky-wave signals

39
Q

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-007-004-007
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

40
Q

B-007-004-008
What causes selective fading?

(a) Small changes in beam heading at the receiving station
(b) Time differences between the receiving and transmitting stations
(c) Large changes in the height of the ionosphere at the receiving station ordinarily occurring shortly before sunrise and sunset
(d) Phase differences between radio wave components of the same transmission, as experienced at the receiving station

A

B-007-004-008
What causes selective fading?

(d) Phase differences between radio wave components of the same transmission, as experienced at the receiving station

41
Q

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

A

B-007-004-009
How does the bandwidth of a transmitted signal affect selective fading?

(d) It is more pronounced at wide bandwidths

42
Q

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) Reflections
(b) Passage through magnetic fields (Faraday rotation)
(c) Refractions
(d) Parabolic interaction

A

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?

(d) Parabolic interaction

43
Q

B-007-004-011
Reflection of a SSB transmission from the ionosphere causes:

(a) phase-shift distortion
(b) signal cancellation at the receiver
(c) little or no phase-shift distortion
(d) a high-pitch squeal at the receiver

A

B-007-004-011
Reflection of a SSB transmission from the ionosphere causes:

(c) little or no phase-shift distortion

44
Q

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

A

B-007-005-001
How do sunspots change the ionization of the atmosphere?

(a) The more sunspots there are, the greater the ionization

45
Q

B-007-005-002
How long is an average sunspot cycle?

(a) 17 years
(b) 5 years
(c) 7 years
(d) 11 years

A

B-007-005-002
How long is an average sunspot cycle?

(d) 11 years

46
Q

B-007-005-003
What is solar flux?

(a) The radio energy emitted by the sun
(b) A measure of the tilt of the Earth’s ionosphere on the side toward the sun
(c) The number of sunspots on the side of the sun facing the Earth
(d) The density of the sun’s magnetic field

A

B-007-005-003
What is solar flux?

(a) The radio energy emitted by the sun

47
Q

B-007-005-004
What is the solar-flux index?

(a) Another name for the American sunspot number
(b) A measure of solar activity that compares daily readings with results from the last six months
(c) A measure of solar activity that is taken annually
(d) A measure of solar activity that is taken at a specific frequency

A

B-007-005-004
What is the solar-flux index?

(d) A measure of solar activity that is taken at a specific frequency

48
Q

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-007-005-005
What influences all radiocommunication beyond ground-wave or line-of-sight ranges?

(a) Solar radiation

49
Q

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

A

B-007-005-006
Which two types of radiation from the sun influence propagation?

(a) Electromagnetic and particle emissions

50
Q

B-007-005-007
When sunspot numbers are high, how is propagation affected?

(a) High frequency radio signals are absorbed
(b) Frequencies up to 40 MHz or even higher become usable for long-distance communication
(c) Frequencies up to 100 MHz or higher are normally usable for long-distance communication
(d) High frequency radio signals become weak and distorted

A

B-007-005-007
When sunspot numbers are high, how is propagation affected?

(b) Frequencies up to 40 MHz or even higher become usable for long-distance communication

51
Q

B-007-005-008
All communication frequencies throughout the spectrum are affected in varying degrees by the:

(a) sun
(b) ionosphere
(c) aurora borealis
(d) atmospheric conditions

A

B-007-005-008
All communication frequencies throughout the spectrum are affected in varying degrees by the:

(a) sun

52
Q

B-007-005-009
Average duration of a solar cycle is:

(a) 3 years
(b) 11 years
(c) 6 years
(d) 1 year

A

B-007-005-009
Average duration of a solar cycle is:

(b) 11 years

53
Q

B-007-005-010
The ability of the ionosphere to reflect high frequency radio signals depends on:

(a) the amount of solar radiation
(b) the power of the transmitted signal
(c) the receiver sensitivity
(d) upper atmosphere weather conditions

A

B-007-005-010
The ability of the ionosphere to reflect high frequency radio signals depends on:

(a) the amount of solar radiation

54
Q

B-007-005-011
HF radio propagation cycles have a period of approximately 11:

(a) months
(b) days
(c) centuries
(d) years

A

B-007-005-011
HF radio propagation cycles have a period of approximately 11:

(d) years

55
Q

B-007-006-001
What happens to signals higher in frequency than the critical frequency?

(a) They are absorbed by the ionosphere
(b) Their frequency is changed by the ionosphere to be below the maximum usable frequency
(c) They are reflected back to their source
(d) They pass through the ionosphere

A

B-007-006-001
What happens to signals higher in frequency than the critical frequency?

(d) They pass through the ionosphere

56
Q

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

A

B-007-006-002
What causes the maximum usable frequency to vary?

(d) The amount of radiation received from the sun, mainly ultraviolet

57
Q

B-007-006-003
What does maximum usable frequency mean?

(a) The lowest frequency signal that will reach its intended destination
(b) The highest frequency signal that is most absorbed by the ionosphere
(c) The lowest frequency signal that is most absorbed by the ionosphere
(d) The highest frequency signal that will reach its intended destination

A

B-007-006-003
What does maximum usable frequency mean?

(d) The highest frequency signal that will reach its intended destination

58
Q

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 higher frequency band
(c) Try a different antenna polarization
(d) Try a different frequency shift

A

B-007-006-004
What can be done at an amateur station to continue HF communications during a sudden ionospheric disturbance?

(b) Try a higher frequency band

59
Q

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 signals from 20-metre beacon stations
(b) Listen for signals from 39-metre broadcast stations
(c) Listen for signals from 10-metre beacon stations
(d) Listen for WWVH time signals on 20 MHz

A

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?

(c) Listen for signals from 10-metre beacon stations

60
Q

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 are changed to a frequency above the MUF
(b) They are completely absorbed by the ionosphere
(c) They pass through the ionosphere
(d) They are bent back to the Earth

A

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?

(d) They are bent back to the Earth

61
Q

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 any point in the solar cycle
(b) Only at the minimum point of the solar cycle
(c) Only at the maximum point of the solar cycle
(d) At the summer solstice

A

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 any point in the solar cycle

62
Q

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) skip distance
(b) speed of light
(c) sunspot frequency
(d) maximum usable frequency

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:

(d) maximum usable frequency

63
Q

B-007-006-009
Communication on the 80 metre band is generally most difficult during:

(a) evening in winter
(b) evening in summer
(c) daytime in winter
(d) daytime in summer

A

B-007-006-009
Communication on the 80 metre band is generally most difficult during:

(d) daytime in summer

64
Q

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

A

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:

(d) slightly lower

65
Q

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

A

B-007-006-011
During summer daytime, which bands are the most difficult for communications beyond ground wave?

(d) 160 and 80 metres

66
Q

B-007-007-001
Which ionospheric region most affects sky-wave propagation on the 6 metre band?

(a) The F2 region
(b) The F1 region
(c) The D region
(d) The E region

A

B-007-007-001
Which ionospheric region most affects sky-wave propagation on the 6 metre band?

(d) The E region

67
Q

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

A

B-007-007-002
What effect does tropospheric bending have on 2-metre radio waves?

(d) It lets you contact stations farther away

68
Q

B-007-007-003
What causes tropospheric ducting of radio waves?

(a) Lightning between the transmitting and receiving stations
(b) A temperature inversion
(c) An aurora to the north
(d) A very low pressure area

A

B-007-007-003
What causes tropospheric ducting of radio waves?

(b) A temperature inversion

69
Q

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) inverted wave
(b) ground wave
(c) ionospheric wave
(d) tropospheric wave

A

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:

(d) tropospheric wave

70
Q

B-007-007-005
What is a sporadic-E condition?

(a) Partial tropospheric ducting at E-region height
(b) Patches of dense ionization at E-region height
(c) Variations in E-region height caused by sunspot variations
(d) A brief decrease in VHF signals caused by sunspot variations

A

B-007-007-005
What is a sporadic-E condition?

(b) Patches of dense ionization at E-region height

71
Q

B-007-007-006
On which amateur frequency band is the extended-distance propagation effect of sporadic-E most often observed?

(a) 160 metres
(b) 20 metres
(c) 2 metres
(d) 6 metres

A

B-007-007-006
On which amateur frequency band is the extended-distance propagation effect of sporadic-E most often observed?

(d) 6 metres

72
Q

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) North
(d) South

A

B-007-007-007
In the northern hemisphere, in which direction should a directional antenna be pointed to take maximum advantage of auroral propagation?

(c) North

73
Q

B-007-007-008
Where in the ionosphere does auroral activity occur?

(a) At F-region height
(b) In the equatorial band
(c) At D-region height
(d) At E-region height

A

B-007-007-008
Where in the ionosphere does auroral activity occur?

(d) At E-region height

74
Q

B-007-007-009
Which emission mode is best for auroral propagation?

(a) RTTY
(b) FM
(c) CW
(d) SSB

A

B-007-007-009
Which emission mode is best for auroral propagation?

(c) CW

75
Q

B-007-007-010
Excluding enhanced propagation modes, what is the approximate range of normal VHF tropospheric propagation?

(a) 2400 km (1500 miles)
(b) 3200 km (2000 miles)
(c) 1600 km (1000 miles)
(d) 800 km (500 miles)

A

B-007-007-010
Excluding enhanced propagation modes, what is the approximate range of normal VHF tropospheric propagation?

(d) 800 km (500 miles)

76
Q

B-007-007-011
What effect is responsible for propagating a VHF signal over 800 km (500 miles)?

(a) Faraday rotation
(b) D-region absorption
(c) Moon bounce (EME) Earth - Moon - Earth
(d) Tropospheric ducting

A

B-007-007-011
What effect is responsible for propagating a VHF signal over 800 km (500 miles)?

(d) Tropospheric ducting

77
Q

B-007-008-001
What kind of unusual HF propagation allows weak signals from the skip zone to be heard occasionally?

(a) Sky-wave with low radiation angle
(b) Ducting
(c) Scatter-mode
(d) Ground-wave

A

B-007-008-001
What kind of unusual HF propagation allows weak signals from the skip zone to be heard occasionally?

(c) Scatter-mode

78
Q

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) Ground-wave
(b) Line-of-sight
(c) Scatter
(d) Ducting

A

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?

(c) Scatter

79
Q

B-007-008-003
What is a characteristic of HF scatter signals?

(a) Reversed modulation
(b) Reversed sidebands
(c) High intelligibility
(d) Rapid flutter or hollow sounding distortion

A

B-007-008-003
What is a characteristic of HF scatter signals?

(d) Rapid flutter or hollow sounding distortion

80
Q

B-007-008-004
What makes HF scatter signals often sound distorted?

(a) Auroral activity and changes in the Earth’s magnetic field
(b) Propagation through ground waves that absorb much of the signal
(c) Energy scattered into the skip zone through several radio-wave paths
(d) The state of the E-region at the point of refraction

A

B-007-008-004
What makes HF scatter signals often sound distorted?

(c) Energy scattered into the skip zone through several radio-wave paths

81
Q

B-007-008-005
Why are HF scatter signals usually weak?

(a) Propagation through ground waves absorbs most of the signal energy
(b) Only a small part of the signal energy is scattered into the skip zone
(c) The F region of the ionosphere absorbs most of the signal energy
(d) Auroral activity absorbs most of the signal energy

A

B-007-008-005
Why are HF scatter signals usually weak?

(b) Only a small part of the signal energy is scattered into the skip zone

82
Q

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) Short-path skip
(b) Sporadic-E skip
(c) Scatter
(d) Ground wave

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?

(c) Scatter

83
Q

B-007-008-007
On the HF bands, when is scatter propagation most likely involved?

(a) When the sunspot cycle is at a minimum and D-region absorption is high
(b) At night
(c) When weak and distorted signals near or above the maximum usable frequency for normal propagation can be heard over unusual paths
(d) When the F1 and F2 regions are combined

A

B-007-008-007
On the HF bands, when is scatter propagation most likely involved?

(c) When weak and distorted signals near or above the maximum usable frequency for normal propagation can be heard over unusual paths

84
Q

B-007-008-008
Which of the following is not a scatter mode?

(a) Meteor scatter
(b) Tropospheric scatter
(c) Ionospheric scatter
(d) Absorption scatter

A

B-007-008-008
Which of the following is not a scatter mode?

(d) Absorption scatter

85
Q

B-007-008-009
Meteor scatter is most effective on what band?

(a) 6 metres
(b) 40 metres
(c) 15 metres
(d) 160 metres

A

B-007-008-009
Meteor scatter is most effective on what band?

(a) 6 metres

86
Q

B-007-008-010
Which of the following is not a scatter mode?

(a) Side scatter
(b) Back scatter
(c) Forward scatter
(d) Inverted scatter

A

B-007-008-010
Which of the following is not a scatter mode?

(d) Inverted scatter

87
Q

B-007-008-011
In which frequency range is meteor scatter most effective for extended-range communication?

(a) 10 - 30 MHz
(b) 3 - 10 MHz
(c) 30 - 100 MHz
(d) 100 - 300 MHz

A

B-007-008-011
In which frequency range is meteor scatter most effective for extended-range communication?

(c) 30 - 100 MHz

ISED - BASIC Radio Amateur (8 decks)

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