G3 - RADIO WAVE PROPAGATION [3 Exam Questions -- 3 Groups]

G3 - RADIO WAVE PROPAGATIONG3 - RADIO WAVE PROPAGATION[3 Exam Questions -- 3 Groups][3 Exam Questions -- 3 Groups]

G3A - Sunspots and solar radiation; ionospheric G3A - Sunspots and solar radiation; ionospheric disturbances; propagation forecasting and disturbances; propagation forecasting and indicesindices

G3B - Maximum Usable Frequency; Lowest Usable G3B - Maximum Usable Frequency; Lowest Usable Frequency; propagationFrequency; propagation

G3C – Ionospheric layers; critical angle and frequency; G3C – Ionospheric layers; critical angle and frequency; HF scatter; Near Vertical Incidence Sky wavesHF scatter; Near Vertical Incidence Sky waves

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Solar EffectsSolar Effects

Sun Spots Sun Spots Sunspots look darker because they’re cooler than surrounding areas but emit ultraviolet light that charge the Ionosphere. More sunspots mean improved upper HF and lower VHF propagation.

Sun Spot CycleSun Spot CycleSunspots tend to come and go from minimum to maximum to Sunspots tend to come and go from minimum to maximum to minimum in an 11 year cycle. Different cycles have different minimum in an 11 year cycle. Different cycles have different maximums.maximums.

Solar EmissionsSolar EmissionsElectromagnetic emissions like ultraviolet and x-rays arrive at the Electromagnetic emissions like ultraviolet and x-rays arrive at the earth in only 8 minutes. Particle emissions can take 20-40 hours earth in only 8 minutes. Particle emissions can take 20-40 hours to arrive at the earth where they are pulled to the poles by the to arrive at the earth where they are pulled to the poles by the earth’s magnetic field.earth’s magnetic field.

Solar RotationThe sun rotates every 28 days (a solar day)

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Measuring the SunMeasuring the Sun

Solar FluxSolar FluxA measure of the sun’s noise at 10.7cm

Solar K-indexThe K-index quantifies disturbances in the horizontal component of earth's magnetic field during a 3 hour interval with an integer in the range 0-9 with 1 being calm and 5 or more indicating a geomagnetic storm

Solar A-indexThe A-index provides a daily average level for geomagnetic activity

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Ionospheric LayersIonospheric Layers

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PropagationPropagation

Ionospheric LayersIonospheric LayersThe Atmosphere is divided into layers A,B,C,D,E,FThe Ionosphere consist of layers D, E, and FThe D layer absorbs low frequenciesThe F layer typically reflects radio waves < 30 MHz

RefractionE layer refraction can be 1200 milesThe higher altitude F layer refraction can be 2500 miles

Balancing Absorption and RefractionD layer absorption defines Lowest Usable Frequency (LUF)E and F layer refraction determine Maximum Usable Frequency (MUF)

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Solar Particles and the MagnetosphereSolar Particles and the Magnetosphere

Solar particle emissions are largely deflected by the Solar particle emissions are largely deflected by the earth’s magnetic field. Some are drawn to the poles earth’s magnetic field. Some are drawn to the poles and generate auroras. and generate auroras.

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Critical AngleCritical Angle

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G3A01 What is the sunspot number?G3A01 What is the sunspot number?

A. A measure of solar activity based on A. A measure of solar activity based on counting sunspots and sunspot groupscounting sunspots and sunspot groups

B. A 3 digit identifier which is used to track B. A 3 digit identifier which is used to track individual sunspotsindividual sunspots

C. A measure of the radio flux from the Sun C. A measure of the radio flux from the Sun measured at 10.7 cmmeasured at 10.7 cm

D. A measure of the sunspot count based on D. A measure of the sunspot count based on radio flux measurementsradio flux measurements

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G3A01 What is the sunspot number?G3A01 What is the sunspot number?

A. A measure of solar activity based on A. A measure of solar activity based on counting sunspots and sunspot groupscounting sunspots and sunspot groups

B. A 3 digit identifier which is used to track B. A 3 digit identifier which is used to track individual sunspotsindividual sunspots

C. A measure of the radio flux from the Sun C. A measure of the radio flux from the Sun measured at 10.7 cmmeasured at 10.7 cm

D. A measure of the sunspot count based on D. A measure of the sunspot count based on radio flux measurementsradio flux measurements

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G3A02 What effect does a Sudden G3A02 What effect does a Sudden Ionospheric Disturbance have on the Ionospheric Disturbance have on the daytime ionospheric propagation of HF daytime ionospheric propagation of HF radio waves?radio waves?

A. It enhances propagation on all HF A. It enhances propagation on all HF frequenciesfrequencies

B. It disrupts signals on lower frequencies more B. It disrupts signals on lower frequencies more than those on higher frequenciesthan those on higher frequencies

C. It disrupts communications via satellite C. It disrupts communications via satellite more than direct communicationsmore than direct communications

D. None, because only areas on the night side D. None, because only areas on the night side of the Earth are affectedof the Earth are affected

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G3A02 What effect does a Sudden G3A02 What effect does a Sudden Ionospheric Disturbance have on the Ionospheric Disturbance have on the daytime ionospheric propagation of HF daytime ionospheric propagation of HF radio waves?radio waves?

A. It enhances propagation on all HF A. It enhances propagation on all HF frequenciesfrequencies

B. It disrupts signals on lower frequencies B. It disrupts signals on lower frequencies more than those on higher frequenciesmore than those on higher frequencies

C. It disrupts communications via satellite C. It disrupts communications via satellite more than direct communicationsmore than direct communications

D. None, because only areas on the night side D. None, because only areas on the night side of the Earth are affectedof the Earth are affected

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G3A03 Approximately how long does it G3A03 Approximately how long does it take the increased ultraviolet and X-ray take the increased ultraviolet and X-ray radiation from solar flares to affect radio-radiation from solar flares to affect radio-wave propagation on the Earth?wave propagation on the Earth?

A. 28 daysA. 28 days

B. 1 to 2 hoursB. 1 to 2 hours

C. 8 minutesC. 8 minutes

D. 20 to 40 hoursD. 20 to 40 hours

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G3A03 Approximately how long does it G3A03 Approximately how long does it take the increased ultraviolet and X-ray take the increased ultraviolet and X-ray radiation from solar flares to affect radio-radiation from solar flares to affect radio-wave propagation on the Earth?wave propagation on the Earth?


B. 1 to 2 hoursB. 1 to 2 hours

C. 8 minutesC. 8 minutes


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G3A04 Which of the following amateur G3A04 Which of the following amateur radio HF frequencies are least reliable for radio HF frequencies are least reliable for long distance communications during long distance communications during periods of low solar activity?periods of low solar activity?

A. 3.5 MHz and lowerA. 3.5 MHz and lower

B. 7 MHzB. 7 MHz

C. 10 MHzC. 10 MHz

D. 21 MHz and higherD. 21 MHz and higher

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G3A04 Which of the following amateur G3A04 Which of the following amateur radio HF frequencies are least reliable for radio HF frequencies are least reliable for long distance communications during long distance communications during periods of low solar activity?periods of low solar activity?

A. 3.5 MHz and lowerA. 3.5 MHz and lower

B. 7 MHzB. 7 MHz

C. 10 MHzC. 10 MHz

D. 21 MHz and higherD. 21 MHz and higher

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G3A05 What is the solar-flux index?G3A05 What is the solar-flux index?

A. A measure of the highest frequency that is A. A measure of the highest frequency that is useful for ionospheric propagation between useful for ionospheric propagation between two points on the Earthtwo points on the Earth

B. A count of sunspots which is adjusted for B. A count of sunspots which is adjusted for solar emissionssolar emissions

C. Another name for the American sunspot C. Another name for the American sunspot numbernumber

D. A measure of solar radiation at 10.7 cmD. A measure of solar radiation at 10.7 cm

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G3A05 What is the solar-flux index?G3A05 What is the solar-flux index?

A. A measure of the highest frequency that is A. A measure of the highest frequency that is useful for ionospheric propagation between useful for ionospheric propagation between two points on the Earthtwo points on the Earth

B. A count of sunspots which is adjusted for B. A count of sunspots which is adjusted for solar emissionssolar emissions

C. Another name for the American sunspot C. Another name for the American sunspot numbernumber

D. A measure of solar radiation at 10.7 cmD. A measure of solar radiation at 10.7 cm

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G3A06 What is a geomagnetic storm?G3A06 What is a geomagnetic storm?

A. A sudden drop in the solar-flux indexA. A sudden drop in the solar-flux index

B. A thunderstorm which affects radio B. A thunderstorm which affects radio propagationpropagation

C. Ripples in the ionosphereC. Ripples in the ionosphere

D. A temporary disturbance in the Earth's D. A temporary disturbance in the Earth's magnetospheremagnetosphere

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G3A06 What is a geomagnetic storm?G3A06 What is a geomagnetic storm?

A. A sudden drop in the solar-flux indexA. A sudden drop in the solar-flux index

B. A thunderstorm which affects radio B. A thunderstorm which affects radio propagationpropagation

C. Ripples in the ionosphereC. Ripples in the ionosphere

D. A temporary disturbance in the Earth's D. A temporary disturbance in the Earth's magnetospheremagnetosphere

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G3A07 At what point in the solar cycle G3A07 At what point in the solar cycle does the 20 meter band usually support does the 20 meter band usually support worldwide propagation during daylight worldwide propagation during daylight hours?hours?

A. At the summer solsticeA. At the summer solstice

B. Only at the maximum point of the solar B. Only at the maximum point of the solar cyclecycle

C. Only at the minimum point of the solar cycleC. Only at the minimum point of the solar cycle

D. At any point in the solar cycleD. At any point in the solar cycle

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G3A07 At what point in the solar cycle G3A07 At what point in the solar cycle does the 20 meter band usually support does the 20 meter band usually support worldwide propagation during daylight worldwide propagation during daylight hours?hours?

A. At the summer solsticeA. At the summer solstice

B. Only at the maximum point of the solar B. Only at the maximum point of the solar cyclecycle

C. Only at the minimum point of the solar cycleC. Only at the minimum point of the solar cycle

D. At any point in the solar cycleD. At any point in the solar cycle

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G3A08 Which of the following effects can G3A08 Which of the following effects can a geomagnetic storm have on radio-wave a geomagnetic storm have on radio-wave propagation?propagation?

A. Improved high-latitude HF propagationA. Improved high-latitude HF propagation

B. Degraded high-latitude HF propagationB. Degraded high-latitude HF propagation

C. Improved ground-wave propagationC. Improved ground-wave propagation

D. Improved chances of UHF ductingD. Improved chances of UHF ducting

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G3A08 Which of the following effects can G3A08 Which of the following effects can a geomagnetic storm have on radio-wave a geomagnetic storm have on radio-wave propagation?propagation?

A. Improved high-latitude HF propagationA. Improved high-latitude HF propagation

B. Degraded high-latitude HF propagationB. Degraded high-latitude HF propagation

C. Improved ground-wave propagationC. Improved ground-wave propagation

D. Improved chances of UHF ductingD. Improved chances of UHF ducting

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G3A09 What effect do high sunspot G3A09 What effect do high sunspot numbers have on radio communications?numbers have on radio communications?

A. High-frequency radio signals become weak A. High-frequency radio signals become weak and distortedand distorted

B. Frequencies above 300 MHz become usable B. Frequencies above 300 MHz become usable for long-distance communicationfor long-distance communication

C. Long-distance communication in the upper C. Long-distance communication in the upper HF and lower VHF range is enhancedHF and lower VHF range is enhanced

D. Microwave communications become D. Microwave communications become unstableunstable

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G3A09 What effect do high sunspot G3A09 What effect do high sunspot numbers have on radio communications?numbers have on radio communications?

A. High-frequency radio signals become weak A. High-frequency radio signals become weak and distortedand distorted

B. Frequencies above 300 MHz become usable B. Frequencies above 300 MHz become usable for long-distance communicationfor long-distance communication

C. Long-distance communication in the C. Long-distance communication in the upper HF and lower VHF range is enhancedupper HF and lower VHF range is enhanced

D. Microwave communications become D. Microwave communications become unstableunstable

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G3A10 What causes HF propagation G3A10 What causes HF propagation conditions to vary periodically in a 28-day conditions to vary periodically in a 28-day cycle?cycle?

A. Long term oscillations in the upper A. Long term oscillations in the upper atmosphereatmosphere

B. Cyclic variation in the Earth’s radiation beltsB. Cyclic variation in the Earth’s radiation belts

C. The Sun’s rotation on its axisC. The Sun’s rotation on its axis

D. The position of the Moon in its orbitD. The position of the Moon in its orbit

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G3A10 What causes HF propagation G3A10 What causes HF propagation conditions to vary periodically in a 28-day conditions to vary periodically in a 28-day cycle?cycle?

A. Long term oscillations in the upper A. Long term oscillations in the upper atmosphereatmosphere

B. Cyclic variation in the Earth’s radiation beltsB. Cyclic variation in the Earth’s radiation belts

C. The Sun’s rotation on its axisC. The Sun’s rotation on its axis

D. The position of the Moon in its orbitD. The position of the Moon in its orbit

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G3A11 Approximately how long is the G3A11 Approximately how long is the typical sunspot cycle?typical sunspot cycle?

A. 8 minutesA. 8 minutes

B. 40 hoursB. 40 hours

C. 28 daysC. 28 days

D. 11 yearsD. 11 years

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G3A11 Approximately how long is the G3A11 Approximately how long is the typical sunspot cycle?typical sunspot cycle?

A. 8 minutesA. 8 minutes

B. 40 hoursB. 40 hours

C. 28 daysC. 28 days

D. 11 yearsD. 11 years

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G3A12 What does the K-index indicate?G3A12 What does the K-index indicate?

A. The relative position of sunspots on the A. The relative position of sunspots on the surface of the Sunsurface of the Sun

B. The short term stability of the Earth’s B. The short term stability of the Earth’s magnetic fieldmagnetic field

C. The stability of the Sun's magnetic fieldC. The stability of the Sun's magnetic field

D. The solar radio flux at Boulder, ColoradoD. The solar radio flux at Boulder, Colorado

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G3A12 What does the K-index indicate?G3A12 What does the K-index indicate?


B. The short term stability of the Earth’s B. The short term stability of the Earth’s magnetic fieldmagnetic field

C. The stability of the Sun's magnetic fieldC. The stability of the Sun's magnetic field


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G3A13 What does the A-index indicate?G3A13 What does the A-index indicate?


B. The amount of polarization of the Sun's B. The amount of polarization of the Sun's electric fieldelectric field

C. The long term stability of the Earth’s C. The long term stability of the Earth’s geomagnetic fieldgeomagnetic field


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G3A13 What does the A-index indicate?G3A13 What does the A-index indicate?


B. The amount of polarization of the Sun's B. The amount of polarization of the Sun's electric fieldelectric field

C. The long term stability of the Earth’s C. The long term stability of the Earth’s geomagnetic fieldgeomagnetic field


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G3A14 How are radio communications G3A14 How are radio communications usually affected by the charged particles usually affected by the charged particles that reach the Earth from solar coronal that reach the Earth from solar coronal holes?holes?

A. HF communications are improvedA. HF communications are improved

B. HF communications are disturbedB. HF communications are disturbed

C. VHF/UHF ducting is improvedC. VHF/UHF ducting is improved

D. VHF/UHF ducting is disturbedD. VHF/UHF ducting is disturbed

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G3A14 How are radio communications G3A14 How are radio communications usually affected by the charged particles usually affected by the charged particles that reach the Earth from solar coronal that reach the Earth from solar coronal holes?holes?

A. HF communications are improvedA. HF communications are improved

B. HF communications are disturbedB. HF communications are disturbed

C. VHF/UHF ducting is improvedC. VHF/UHF ducting is improved

D. VHF/UHF ducting is disturbedD. VHF/UHF ducting is disturbed

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G3A15 How long does it take charged G3A15 How long does it take charged particles from coronal mass ejections to particles from coronal mass ejections to affect radio-wave propagation on the affect radio-wave propagation on the Earth?Earth?


B. 14 daysB. 14 days

C. 4 to 8 minutesC. 4 to 8 minutes


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G3A15 How long does it take charged G3A15 How long does it take charged particles from coronal mass ejections to particles from coronal mass ejections to affect radio-wave propagation on the affect radio-wave propagation on the Earth?Earth?


B. 14 daysB. 14 days

C. 4 to 8 minutesC. 4 to 8 minutes


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G3A16 What is a possible benefit to radio G3A16 What is a possible benefit to radio communications resulting from periods of communications resulting from periods of high geomagnetic activity?high geomagnetic activity?

A. Aurora that can reflect VHF signalsA. Aurora that can reflect VHF signals

B. Higher signal strength for HF signals passing B. Higher signal strength for HF signals passing through the polar regionsthrough the polar regions

C. Improved HF long path propagationC. Improved HF long path propagation

D. Reduced long delayed echoesD. Reduced long delayed echoes

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G3A16 What is a possible benefit to radio G3A16 What is a possible benefit to radio communications resulting from periods of communications resulting from periods of high geomagnetic activity?high geomagnetic activity?

A. Aurora that can reflect VHF signalsA. Aurora that can reflect VHF signals

B. Higher signal strength for HF signals passing B. Higher signal strength for HF signals passing through the polar regionsthrough the polar regions

C. Improved HF long path propagationC. Improved HF long path propagation

D. Reduced long delayed echoesD. Reduced long delayed echoes

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IBP/NCDXF Beacon TransmissionsIBP/NCDXF Beacon TransmissionsFrequencyFrequency

CountryCountry CallCall 1410014100 1811018110 2115021150 2493024930 2820028200

UN, NYUN, NY 4U1UN4U1UN 00.0000.00 00.1000.10 00.2000.20 00.3000.30 00.4000.40Northern CanadaNorthern Canada VE8ATVE8AT 00.1000.10 00.2000.20 00.3000.30 00.4000.40 00.5000.50USA (CA)USA (CA) W6WXW6WX 00:2000:20 00.3000.30 00:4000:40 00.5000.50 01:0001:00HawaiiHawaii KH6WOKH6WO 00.3000.30 - - 00.5000.50 - - 01.1001.10New ZealandNew Zealand ZL6BZL6B 00.4000.40 00.5000.50 01.0001.00 01.1001.10 01.2001.20West AustraliaWest Australia VK6RBPVK6RBP 00.5000.50 01.0001.00 01.1001.10 01.2001.20

01.3001.30JapanJapan JA2IGYJA2IGY 01.0001.00 01.1001.10 01.2001.20 01.3001.30 01.4001.40SiberiaSiberia RR9ORR9O 01.1001.10 01.2001.20 01.3001.30 01.4001.40 01.5001.50ChinaChina VR2HKVR2HK 01.2001.20 01.3001.30 01.4001.40 01.5001.50 02.0002.00Sri LankaSri Lanka 4S7B4S7B 01.3001.30 01.4001.40 01.5001.50 02.0002.00 02.1002.10South AfricaSouth Africa ZS6DNZS6DN 01:4001:40 01.5001.50 02:0002:00 02:1002:10 02:2002:20KenyaKenya 5Z4B5Z4B 01.5001.50 02.0002.00 02.1002.10 02.2002.20 02.3002.30IsraelIsrael 4X6TU4X6TU 02:0002:00 02:1002:10 02:2002:20 02.3002.30 02:4002:40FinlandFinland OH2BOH2B 02:1002:10 02:2002:20 02:3002:30 02:4002:40 02:5002:50MadeiraMadeira CS3BCS3B 02.2002.20 02.3002.30 02.4002.40 02.5002.50 00.0000.00ArgentinaArgentina LU4AALU4AA 02:3002:30 02:4002:40 02:5002:50 00.0000.00 00:1000:10PeruPeru OA4BOA4B 02.4002.40 02.5002.50 00.0000.00 00.1000.10 00.2000.20VenezuelaVenezuela YV5BYV5B 02:5002:50 00.0000.00 00:1000:10 00:2000:20 00:30 00:30

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Backscatter PropagationBackscatter Propagation

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G3B01 How might a sky-wave signal G3B01 How might a sky-wave signal sound if it arrives at your receiver by both sound if it arrives at your receiver by both short path and long path propagation?short path and long path propagation?

A. Periodic fading approximately every 10 A. Periodic fading approximately every 10 secondsseconds

B. Signal strength increased by 3 dBB. Signal strength increased by 3 dB

C. The signal might be cancelled causing C. The signal might be cancelled causing severe attenuationsevere attenuation

D. A well-defined echo might be heardD. A well-defined echo might be heard

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G3B01 How might a sky-wave signal G3B01 How might a sky-wave signal sound if it arrives at your receiver by both sound if it arrives at your receiver by both short path and long path propagation?short path and long path propagation?

A. Periodic fading approximately every 10 A. Periodic fading approximately every 10 secondsseconds

B. Signal strength increased by 3 dBB. Signal strength increased by 3 dB

C. The signal might be cancelled causing C. The signal might be cancelled causing severe attenuationsevere attenuation

D. A well-defined echo might be heardD. A well-defined echo might be heard

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G3B02 Which of the following is a good G3B02 Which of the following is a good indicator of the possibility of sky-wave indicator of the possibility of sky-wave propagation on the 6 meter band?propagation on the 6 meter band?

A. Short skip sky-wave propagation on the 10 A. Short skip sky-wave propagation on the 10 meter bandmeter band

B. Long skip sky-wave propagation on the 10 B. Long skip sky-wave propagation on the 10 meter bandmeter band

C. Severe attenuation of signals on the 10 C. Severe attenuation of signals on the 10 meter bandmeter band

D. Long delayed echoes on the 10 meter bandD. Long delayed echoes on the 10 meter band

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G3B02 Which of the following is a good G3B02 Which of the following is a good indicator of the possibility of sky-wave indicator of the possibility of sky-wave propagation on the 6 meter band?propagation on the 6 meter band?

A. Short skip sky-wave propagation on the A. Short skip sky-wave propagation on the 10 meter band10 meter band

B. Long skip sky-wave propagation on the 10 B. Long skip sky-wave propagation on the 10 meter bandmeter band

C. Severe attenuation of signals on the 10 C. Severe attenuation of signals on the 10 meter bandmeter band

D. Long delayed echoes on the 10 meter bandD. Long delayed echoes on the 10 meter band

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G3B03 Which of the following applies G3B03 Which of the following applies when selecting a frequency for lowest when selecting a frequency for lowest attenuation when transmitting on HF?attenuation when transmitting on HF?

A. Select a frequency just below the MUFA. Select a frequency just below the MUF

B. Select a frequency just above the LUFB. Select a frequency just above the LUF

C. Select a frequency just below the critical C. Select a frequency just below the critical frequencyfrequency

D. Select a frequency just above the critical D. Select a frequency just above the critical frequencyfrequency

47

G3B03 Which of the following applies G3B03 Which of the following applies when selecting a frequency for lowest when selecting a frequency for lowest attenuation when transmitting on HF?attenuation when transmitting on HF?

A. Select a frequency just below the MUFA. Select a frequency just below the MUF

B. Select a frequency just above the LUFB. Select a frequency just above the LUF

C. Select a frequency just below the critical C. Select a frequency just below the critical frequencyfrequency

D. Select a frequency just above the critical D. Select a frequency just above the critical frequencyfrequency

48

G3B04 What is a reliable way to G3B04 What is a reliable way to determine if the Maximum Usable determine if the Maximum Usable Frequency (MUF) is high enough to Frequency (MUF) is high enough to support skip propagation between your support skip propagation between your station and a distant location on station and a distant location on frequencies between 14 and 30 MHz?frequencies between 14 and 30 MHz?

A. Listen for signals from an international A. Listen for signals from an international beaconbeacon

B. Send a series of dots on the band and listen B. Send a series of dots on the band and listen for echoes from your signalfor echoes from your signal

C. Check the strength of TV signals from C. Check the strength of TV signals from Western EuropeWestern Europe

D. Check the strength of signals in the MF AM D. Check the strength of signals in the MF AM broadcast bandbroadcast band

49

G3B04 What is a reliable way to G3B04 What is a reliable way to determine if the Maximum Usable determine if the Maximum Usable Frequency (MUF) is high enough to Frequency (MUF) is high enough to support skip propagation between your support skip propagation between your station and a distant location on station and a distant location on frequencies between 14 and 30 MHz?frequencies between 14 and 30 MHz?

A. Listen for signals from an international A. Listen for signals from an international beaconbeacon

B. Send a series of dots on the band and listen B. Send a series of dots on the band and listen for echoes from your signalfor echoes from your signal

C. Check the strength of TV signals from C. Check the strength of TV signals from Western EuropeWestern Europe

D. Check the strength of signals in the MF AM D. Check the strength of signals in the MF AM broadcast bandbroadcast band

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G3B05 What usually happens to radio G3B05 What usually happens to radio waves with frequencies below the waves with frequencies below the Maximum Usable Frequency (MUF) and Maximum Usable Frequency (MUF) and above the Lowest Usable Frequency (LUF) above the Lowest Usable Frequency (LUF) when they are sent into the ionosphere?when they are sent into the ionosphere?

A. They are bent back to the EarthA. They are bent back to the Earth

B. They pass through the ionosphereB. They pass through the ionosphere

C. They are amplified by interaction with the C. They are amplified by interaction with the ionosphereionosphere

D. They are bent and trapped in the ionosphere D. They are bent and trapped in the ionosphere to circle the Earthto circle the Earth

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G3B05 What usually happens to radio G3B05 What usually happens to radio waves with frequencies below the waves with frequencies below the Maximum Usable Frequency (MUF) and Maximum Usable Frequency (MUF) and above the Lowest Usable Frequency (LUF) above the Lowest Usable Frequency (LUF) when they are sent into the ionosphere?when they are sent into the ionosphere?



C. They are amplified by interaction with the C. They are amplified by interaction with the ionosphereionosphere


52

G3B06 What usually happens to radio G3B06 What usually happens to radio waves with frequencies below the Lowest waves with frequencies below the Lowest Usable Frequency (LUF)?Usable Frequency (LUF)?



C. They are completely absorbed by the C. They are completely absorbed by the ionosphereionosphere


53

G3B06 What usually happens to radio G3B06 What usually happens to radio waves with frequencies below the Lowest waves with frequencies below the Lowest Usable Frequency (LUF)?Usable Frequency (LUF)?



C. They are completely absorbed by the C. They are completely absorbed by the ionosphereionosphere


54

G3B07 What does LUF stand for?G3B07 What does LUF stand for?

A. The Lowest Usable Frequency for A. The Lowest Usable Frequency for communications between two pointscommunications between two points

B. The Longest Universal Function for B. The Longest Universal Function for communications between two pointscommunications between two points

C. The Lowest Usable Frequency during a 24 C. The Lowest Usable Frequency during a 24 hour periodhour period

D. The Longest Universal Function during a 24 D. The Longest Universal Function during a 24 hour periodhour period

55

G3B07 What does LUF stand for?G3B07 What does LUF stand for?

A. The Lowest Usable Frequency for A. The Lowest Usable Frequency for communications between two pointscommunications between two points

B. The Longest Universal Function for B. The Longest Universal Function for communications between two pointscommunications between two points

C. The Lowest Usable Frequency during a 24 C. The Lowest Usable Frequency during a 24 hour periodhour period

D. The Longest Universal Function during a 24 D. The Longest Universal Function during a 24 hour periodhour period

56

G3B08 What does MUF stand for?G3B08 What does MUF stand for?

A. The Minimum Usable Frequency for A. The Minimum Usable Frequency for communications between two pointscommunications between two points

B. The Maximum Usable Frequency for B. The Maximum Usable Frequency for communications between two pointscommunications between two points

C. The Minimum Usable Frequency during a 24 C. The Minimum Usable Frequency during a 24 hour periodhour period

D. The Maximum Usable Frequency during a 24 D. The Maximum Usable Frequency during a 24 hour periodhour period

57

G3B08 What does MUF stand for?G3B08 What does MUF stand for?

A. The Minimum Usable Frequency for A. The Minimum Usable Frequency for communications between two pointscommunications between two points

B. The Maximum Usable Frequency for B. The Maximum Usable Frequency for communications between two pointscommunications between two points

C. The Minimum Usable Frequency during a 24 C. The Minimum Usable Frequency during a 24 hour periodhour period

D. The Maximum Usable Frequency during a 24 D. The Maximum Usable Frequency during a 24 hour periodhour period

58

G3B09 What is the approximate G3B09 What is the approximate maximum distance along the Earth's maximum distance along the Earth's surface that is normally covered in one surface that is normally covered in one hop using the F2 region?hop using the F2 region?

A. 180 milesA. 180 miles

B. 1,200 milesB. 1,200 miles

C. 2,500 milesC. 2,500 miles

D. 12,000 milesD. 12,000 miles

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G3B09 What is the approximate G3B09 What is the approximate maximum distance along the Earth's maximum distance along the Earth's surface that is normally covered in one surface that is normally covered in one hop using the F2 region?hop using the F2 region?





60

G3B10 What is the approximate G3B10 What is the approximate maximum distance along the Earth's maximum distance along the Earth's surface that is normally covered in one surface that is normally covered in one hop using the E region?hop using the E region?





61

G3B10 What is the approximate G3B10 What is the approximate maximum distance along the Earth's maximum distance along the Earth's surface that is normally covered in one surface that is normally covered in one hop using the E region?hop using the E region?





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G3B11 What happens to HF propagation G3B11 What happens to HF propagation when the Lowest Usable Frequency (LUF) when the Lowest Usable Frequency (LUF) exceeds the Maximum Usable Frequency exceeds the Maximum Usable Frequency (MUF)?(MUF)?

A. No HF radio frequency will support ordinary A. No HF radio frequency will support ordinary skywave communications over the pathskywave communications over the path

B. HF communications over the path are B. HF communications over the path are enhancedenhanced

C. Double hop propagation along the path is C. Double hop propagation along the path is more commonmore common

D. Propagation over the path on all HF D. Propagation over the path on all HF frequencies is enhancedfrequencies is enhanced

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G3B11 What happens to HF propagation G3B11 What happens to HF propagation when the Lowest Usable Frequency (LUF) when the Lowest Usable Frequency (LUF) exceeds the Maximum Usable Frequency exceeds the Maximum Usable Frequency (MUF)?(MUF)?

A. No HF radio frequency will support ordinary A. No HF radio frequency will support ordinary skywave communications over the pathskywave communications over the path

B. HF communications over the path are enhancedB. HF communications over the path are enhanced

C. Double hop propagation along the path is more C. Double hop propagation along the path is more commoncommon

D. Propagation over the path on all HF frequencies D. Propagation over the path on all HF frequencies is enhancedis enhanced

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G3B12 What factors affect the Maximum G3B12 What factors affect the Maximum Usable Frequency (MUF)?Usable Frequency (MUF)?

A. Path distance and locationA. Path distance and location

B. Time of day and seasonB. Time of day and season

C. Solar radiation and ionospheric disturbancesC. Solar radiation and ionospheric disturbances

D. All of these choices are correctD. All of these choices are correct

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G3B12 What factors affect the Maximum G3B12 What factors affect the Maximum Usable Frequency (MUF)?Usable Frequency (MUF)?

A. Path distance and locationA. Path distance and location

B. Time of day and seasonB. Time of day and season

C. Solar radiation and ionospheric disturbancesC. Solar radiation and ionospheric disturbances


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G3C01 Which of the following ionospheric G3C01 Which of the following ionospheric layers is closest to the surface of the layers is closest to the surface of the Earth?Earth?

A. The D layerA. The D layer

B. The E layerB. The E layer

C. The F1 layerC. The F1 layer

D. The F2 layerD. The F2 layer

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G3C01 Which of the following ionospheric G3C01 Which of the following ionospheric layers is closest to the surface of the layers is closest to the surface of the Earth?Earth?

A. The D layerA. The D layer

B. The E layerB. The E layer

C. The F1 layerC. The F1 layer

D. The F2 layerD. The F2 layer

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G3C02 Where on the Earth do ionospheric G3C02 Where on the Earth do ionospheric layers reach their maximum height?layers reach their maximum height?

A. Where the Sun is overheadA. Where the Sun is overhead

B. Where the Sun is on the opposite side of the B. Where the Sun is on the opposite side of the EarthEarth

C. Where the Sun is risingC. Where the Sun is rising

D. Where the Sun has just setD. Where the Sun has just set

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G3C02 Where on the Earth do ionospheric G3C02 Where on the Earth do ionospheric layers reach their maximum height?layers reach their maximum height?

A. Where the Sun is overheadA. Where the Sun is overhead

B. Where the Sun is on the opposite side of the B. Where the Sun is on the opposite side of the EarthEarth

C. Where the Sun is risingC. Where the Sun is rising

D. Where the Sun has just setD. Where the Sun has just set

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G3C03 Why is the F2 region mainly G3C03 Why is the F2 region mainly responsible for the longest distance radio responsible for the longest distance radio wave propagation?wave propagation?

A. Because it is the densest ionospheric layerA. Because it is the densest ionospheric layer

B. Because it does not absorb radio waves as B. Because it does not absorb radio waves as much as other ionospheric regionsmuch as other ionospheric regions

C. Because it is the highest ionospheric regionC. Because it is the highest ionospheric region


71

G3C03 Why is the F2 region mainly G3C03 Why is the F2 region mainly responsible for the longest distance radio responsible for the longest distance radio wave propagation?wave propagation?

A. Because it is the densest ionospheric layerA. Because it is the densest ionospheric layer

B. Because it does not absorb radio waves as B. Because it does not absorb radio waves as much as other ionospheric regionsmuch as other ionospheric regions

C. Because it is the highest ionospheric C. Because it is the highest ionospheric regionregion


72

G3C04 What does the term “critical G3C04 What does the term “critical angle” mean as used in radio wave angle” mean as used in radio wave propagation?propagation?

A. The long path azimuth of a distant stationA. The long path azimuth of a distant station

B. The short path azimuth of a distant stationB. The short path azimuth of a distant station

C. The lowest takeoff angle that will return a C. The lowest takeoff angle that will return a radio wave to the Earth under specific radio wave to the Earth under specific ionospheric conditionsionospheric conditions

D. The highest takeoff angle that will return a D. The highest takeoff angle that will return a radio wave to the Earth under specific radio wave to the Earth under specific ionospheric conditionsionospheric conditions

73

G3C04 What does the term “critical G3C04 What does the term “critical angle” mean as used in radio wave angle” mean as used in radio wave propagation?propagation?

A. The long path azimuth of a distant stationA. The long path azimuth of a distant station

B. The short path azimuth of a distant stationB. The short path azimuth of a distant station

C. The lowest takeoff angle that will return a C. The lowest takeoff angle that will return a radio wave to the Earth under specific radio wave to the Earth under specific ionospheric conditionsionospheric conditions

D. The highest takeoff angle that will return D. The highest takeoff angle that will return a radio wave to the Earth under specific a radio wave to the Earth under specific ionospheric conditionsionospheric conditions

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G3C05 Why is long distance G3C05 Why is long distance communication on the 40, 60, 80 and 160 communication on the 40, 60, 80 and 160 meter bands more difficult during the meter bands more difficult during the day?day?

A. The F layer absorbs signals at these A. The F layer absorbs signals at these frequencies during daylight hoursfrequencies during daylight hours

B. The F layer is unstable during daylight hoursB. The F layer is unstable during daylight hours

C. The D layer absorbs signals at these C. The D layer absorbs signals at these frequencies during daylight hoursfrequencies during daylight hours

D. The E layer is unstable during daylight hoursD. The E layer is unstable during daylight hours

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G3C05 Why is long distance G3C05 Why is long distance communication on the 40, 60, 80 and 160 communication on the 40, 60, 80 and 160 meter bands more difficult during the meter bands more difficult during the day?day?

A. The F layer absorbs signals at these A. The F layer absorbs signals at these frequencies during daylight hoursfrequencies during daylight hours

B. The F layer is unstable during daylight hoursB. The F layer is unstable during daylight hours

C. The D layer absorbs signals at these C. The D layer absorbs signals at these frequencies during daylight hoursfrequencies during daylight hours

D. The E layer is unstable during daylight hoursD. The E layer is unstable during daylight hours

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G3C06 What is a characteristic of HF G3C06 What is a characteristic of HF scatter signals?scatter signals?

A. They have high intelligibilityA. They have high intelligibility

B. They have a wavering soundB. They have a wavering sound

C. They have very large swings in signal C. They have very large swings in signal strengthstrength


77

G3C06 What is a characteristic of HF G3C06 What is a characteristic of HF scatter signals?scatter signals?

A. They have high intelligibilityA. They have high intelligibility

B. They have a wavering soundB. They have a wavering sound

C. They have very large swings in signal C. They have very large swings in signal strengthstrength


78

G3C07 What makes HF scatter signals G3C07 What makes HF scatter signals often sound distorted?often sound distorted?

A. The ionospheric layer involved is unstableA. The ionospheric layer involved is unstable

B. Ground waves are absorbing much of the B. Ground waves are absorbing much of the signalsignal

C. The E-region is not presentC. The E-region is not present

D. Energy is scattered into the skip zone D. Energy is scattered into the skip zone through several different radio wave pathsthrough several different radio wave paths

79

G3C07 What makes HF scatter signals G3C07 What makes HF scatter signals often sound distorted?often sound distorted?

A. The ionospheric layer involved is unstableA. The ionospheric layer involved is unstable

B. Ground waves are absorbing much of the B. Ground waves are absorbing much of the signalsignal

C. The E-region is not presentC. The E-region is not present

D. Energy is scattered into the skip zone D. Energy is scattered into the skip zone through several different radio wave pathsthrough several different radio wave paths

80

G3C08 Why are HF scatter signals in the G3C08 Why are HF scatter signals in the skip zone usually weak?skip zone usually weak?

A. Only a small part of the signal energy is A. Only a small part of the signal energy is scattered into the skip zonescattered into the skip zone

B. Signals are scattered from the B. Signals are scattered from the magnetosphere which is not a good reflectormagnetosphere which is not a good reflector

C. Propagation is through ground waves which C. Propagation is through ground waves which absorb most of the signal energyabsorb most of the signal energy

D. Propagations is through ducts in F region D. Propagations is through ducts in F region which absorb most of the energywhich absorb most of the energy

81

G3C08 Why are HF scatter signals in the G3C08 Why are HF scatter signals in the skip zone usually weak?skip zone usually weak?

A. Only a small part of the signal energy is A. Only a small part of the signal energy is scattered into the skip zonescattered into the skip zone

B. Signals are scattered from the B. Signals are scattered from the magnetosphere which is not a good reflectormagnetosphere which is not a good reflector

C. Propagation is through ground waves which C. Propagation is through ground waves which absorb most of the signal energyabsorb most of the signal energy

D. Propagations is through ducts in F region D. Propagations is through ducts in F region which absorb most of the energywhich absorb most of the energy

82

G3C09 What type of radio wave G3C09 What type of radio wave propagation allows a signal to be propagation allows a signal to be detected at a distance too far for ground detected at a distance too far for ground wave propagation but too near for normal wave propagation but too near for normal sky-wave propagation?sky-wave propagation?

A. Faraday rotationA. Faraday rotation

B. ScatterB. Scatter

C. Sporadic-E skipC. Sporadic-E skip

D. Short-path skipD. Short-path skip

83

G3C09 What type of radio wave G3C09 What type of radio wave propagation allows a signal to be propagation allows a signal to be detected at a distance too far for ground detected at a distance too far for ground wave propagation but too near for normal wave propagation but too near for normal sky-wave propagation?sky-wave propagation?

A. Faraday rotationA. Faraday rotation

B. ScatterB. Scatter

C. Sporadic-E skipC. Sporadic-E skip

D. Short-path skipD. Short-path skip

84

G3C10 Which of the following might be an G3C10 Which of the following might be an indication that signals heard on the HF indication that signals heard on the HF bands are being received via scatter bands are being received via scatter propagation?propagation?

A. The communication is during a sunspot A. The communication is during a sunspot maximummaximum

B. The communication is during a sudden B. The communication is during a sudden ionospheric disturbanceionospheric disturbance

C. The signal is heard on a frequency below the C. The signal is heard on a frequency below the Maximum Usable FrequencyMaximum Usable Frequency

D. The signal is heard on a frequency above D. The signal is heard on a frequency above the Maximum Usable Frequencythe Maximum Usable Frequency

85

G3C10 Which of the following might be an G3C10 Which of the following might be an indication that signals heard on the HF indication that signals heard on the HF bands are being received via scatter bands are being received via scatter propagation?propagation?

A. The communication is during a sunspot A. The communication is during a sunspot maximummaximum

B. The communication is during a sudden B. The communication is during a sudden ionospheric disturbanceionospheric disturbance

C. The signal is heard on a frequency below the C. The signal is heard on a frequency below the Maximum Usable FrequencyMaximum Usable Frequency

D. The signal is heard on a frequency above D. The signal is heard on a frequency above the Maximum Usable Frequencythe Maximum Usable Frequency

86

G3C11 Which of the following antenna G3C11 Which of the following antenna types will be most effective for skip types will be most effective for skip communications on 40 meters during the communications on 40 meters during the day?day?

A. Vertical antennasA. Vertical antennas

B. Horizontal dipoles placed between 1/8 and B. Horizontal dipoles placed between 1/8 and 1/4 wavelength above the ground1/4 wavelength above the ground

C. Left-hand circularly polarized antennasC. Left-hand circularly polarized antennas

D. Right-hand circularly polarized antennaD. Right-hand circularly polarized antenna

87

G3C11 Which of the following antenna G3C11 Which of the following antenna types will be most effective for skip types will be most effective for skip communications on 40 meters during the communications on 40 meters during the day?day?

A. Vertical antennasA. Vertical antennas

B. Horizontal dipoles placed between 1/8 B. Horizontal dipoles placed between 1/8 and 1/4 wavelength above the groundand 1/4 wavelength above the ground

C. Left-hand circularly polarized antennasC. Left-hand circularly polarized antennas

D. Right-hand circularly polarized antennaD. Right-hand circularly polarized antenna

88

G3C12 Which ionospheric layer is the G3C12 Which ionospheric layer is the most absorbent of long skip signals most absorbent of long skip signals during daylight hours on frequencies during daylight hours on frequencies below 10 MHz?below 10 MHz?

A. The F2 layerA. The F2 layer

B. The F1 layerB. The F1 layer

C. The E layerC. The E layer

D. The D layerD. The D layer

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G3C12 Which ionospheric layer is the G3C12 Which ionospheric layer is the most absorbent of long skip signals most absorbent of long skip signals during daylight hours on frequencies during daylight hours on frequencies below 10 MHz?below 10 MHz?

A. The F2 layerA. The F2 layer

B. The F1 layerB. The F1 layer

C. The E layerC. The E layer

D. The D layerD. The D layer

90

G3C13 What is Near Vertical Incidence G3C13 What is Near Vertical Incidence Sky-wave (NVIS) propagation?Sky-wave (NVIS) propagation?

A. Propagation near the MUFA. Propagation near the MUF

B. Short distance HF propagation using high B. Short distance HF propagation using high elevation angleselevation angles

C. Long path HF propagation at sunrise and C. Long path HF propagation at sunrise and sunsetsunset

D. Double hop propagation near the LUFD. Double hop propagation near the LUF

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G3C13 What is Near Vertical Incidence G3C13 What is Near Vertical Incidence Sky-wave (NVIS) propagation?Sky-wave (NVIS) propagation?

A. Propagation near the MUFA. Propagation near the MUF

B. Short distance HF propagation using high B. Short distance HF propagation using high elevation angleselevation angles

C. Long path HF propagation at sunrise and C. Long path HF propagation at sunrise and sunsetsunset

D. Double hop propagation near the LUFD. Double hop propagation near the LUF

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G3 - RADIO WAVE PROPAGATIONG3 - RADIO WAVE PROPAGATION[3 Exam Questions -- 3 Groups][3 Exam Questions -- 3 Groups]

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G3 - RADIO WAVE PROPAGATION [3 Exam Questions -- 3 Groups]