subelement t3 [3 exam questions - 3 groups] radio wave characteristics, radio and electromagnetic...

SUBELEMENT T3SUBELEMENT T3[3 Exam Questions - 3 Groups][3 Exam Questions - 3 Groups]

Radio wave characteristics, radio and electromagnetic properties, propagation modes

2Microhams 2010 Technician

T3 – Radio WavesT3 – Radio Waves

T3AT3A - Radio wave characteristics; how a radio signal - Radio wave characteristics; how a radio signal travels; distinctions of HF, VHF and UHF; fading, travels; distinctions of HF, VHF and UHF; fading, multipath; wavelength vs. penetration; antenna multipath; wavelength vs. penetration; antenna orientationorientation

T3BT3B - Radio and electromagnetic wave properties; the - Radio and electromagnetic wave properties; the electromagnetic spectrum, wavelength vs. frequency, electromagnetic spectrum, wavelength vs. frequency, velocity of electromagnetic wavesvelocity of electromagnetic waves

T3CT3C - Propagation modes; line of sight, sporadic E, - Propagation modes; line of sight, sporadic E, meteor, aurora scatter, tropospheric ducting, F layer meteor, aurora scatter, tropospheric ducting, F layer skip, radio horizonskip, radio horizon


T3A01 What should you do if another T3A01 What should you do if another operator reports that your station's 2 meter operator reports that your station's 2 meter signals were strong just a moment ago, signals were strong just a moment ago, but now they are weak or distorted?but now they are weak or distorted?

A.A. Change the batteries in your radio to a different typeChange the batteries in your radio to a different type

B.B. Turn on the CTCSS toneTurn on the CTCSS tone

C.C. Ask the other operator to adjust his squelch controlAsk the other operator to adjust his squelch control

D.D. Try moving a few feet, as random reflections may be Try moving a few feet, as random reflections may be causing multi-path distortioncausing multi-path distortion


T3A01 What should you do if another operator T3A01 What should you do if another operator reports that your station's 2 meter signals reports that your station's 2 meter signals were strong just a moment ago, but now they were strong just a moment ago, but now they are weak or distorted?are weak or distorted?

A.A. Change the batteries in your radio to a different typeChange the batteries in your radio to a different type

B.B. Turn on the CTCSS toneTurn on the CTCSS tone

C.C. Ask the other operator to adjust his squelch controlAsk the other operator to adjust his squelch control

D.D. Try moving a few feet, as random Try moving a few feet, as random reflections may be causing multi-path reflections may be causing multi-path distortiondistortion


T3A02 Why are UHF signals often more T3A02 Why are UHF signals often more effective from inside buildings than VHF effective from inside buildings than VHF signals?signals?

A.A. VHF signals lose power faster over distanceVHF signals lose power faster over distance

B.B. The shorter wavelength allows them to more easily The shorter wavelength allows them to more easily penetrate the structure of buildingspenetrate the structure of buildings

C.C. This is incorrect; VHF works better than UHF inside This is incorrect; VHF works better than UHF inside buildingsbuildings

D.D. UHF antennas are more efficient than VHF antennasUHF antennas are more efficient than VHF antennas


T3A02 Why are UHF signals often more T3A02 Why are UHF signals often more effective from inside buildings than VHF effective from inside buildings than VHF signals?signals?

A.A. VHF signals lose power faster over distanceVHF signals lose power faster over distance

B.B. The shorter wavelength allows them to The shorter wavelength allows them to more easily penetrate the structure of more easily penetrate the structure of buildingsbuildingsC.C. This is incorrect; VHF works better than UHF inside This is incorrect; VHF works better than UHF inside

buildingsbuildings

D.D. UHF antennas are more efficient than VHF antennasUHF antennas are more efficient than VHF antennas


T3A03 What antenna polarization is T3A03 What antenna polarization is normally used for long-distance weak-normally used for long-distance weak-signal CW and SSB contacts using the signal CW and SSB contacts using the VHF and UHF bands?VHF and UHF bands?

A.A. Right-hand circularRight-hand circular

B.B. Left-hand circularLeft-hand circular

C.C. HorizontalHorizontal

D.D. VerticalVertical


T3A03 What antenna polarization is normally T3A03 What antenna polarization is normally used for long-distance weak-signal CW and used for long-distance weak-signal CW and SSB contacts using the VHF and UHF bands?SSB contacts using the VHF and UHF bands?

A.A. Right-hand circularRight-hand circular

B.B. Left-hand circularLeft-hand circular

C.C. HorizontalHorizontalD.D. VerticalVertical


T3A04 What can happen if the antennas at T3A04 What can happen if the antennas at opposite ends of a VHF or UHF line of opposite ends of a VHF or UHF line of sight radio link are not using the same sight radio link are not using the same polarization?polarization?

A.A. The modulation sidebands might become invertedThe modulation sidebands might become inverted

B.B. Signals could be significantly weakerSignals could be significantly weaker

C.C. Signals have an echo effect on voicesSignals have an echo effect on voices

D.D. Nothing significant will happenNothing significant will happen


T3A04 What can happen if the antennas at T3A04 What can happen if the antennas at opposite ends of a VHF or UHF line of sight opposite ends of a VHF or UHF line of sight radio link are not using the same polarization?radio link are not using the same polarization?

A.A. The modulation sidebands might become invertedThe modulation sidebands might become inverted

B.B. Signals could be significantly weakerSignals could be significantly weakerC.C. Signals have an echo effect on voicesSignals have an echo effect on voices

D.D. Nothing significant will happenNothing significant will happen


T3A05 When using a directional antenna, T3A05 When using a directional antenna, how might your station be able to access a how might your station be able to access a distant repeater if buildings or distant repeater if buildings or obstructions are blocking the direct line of obstructions are blocking the direct line of sight path?sight path?

A.A. Change from vertical to horizontal polarizationChange from vertical to horizontal polarization

B.B. Try to find a path that reflects signals to the repeaterTry to find a path that reflects signals to the repeater

C.C. Try the long pathTry the long path

D.D. Increase the antenna SWRIncrease the antenna SWR


T3A05 When using a directional antenna, how T3A05 When using a directional antenna, how might your station be able to access a distant might your station be able to access a distant repeater if buildings or obstructions are repeater if buildings or obstructions are blocking the direct line of sight path?blocking the direct line of sight path?

A.A. Change from vertical to horizontal polarizationChange from vertical to horizontal polarization

B.B. Try to find a path that reflects signals to Try to find a path that reflects signals to the repeaterthe repeaterC.C. Try the long pathTry the long path

D.D. Increase the antenna SWRIncrease the antenna SWR


T3A06 What term is commonly used to T3A06 What term is commonly used to describe the rapid fluttering sound describe the rapid fluttering sound sometimes heard from mobile stations that sometimes heard from mobile stations that are moving while transmitting?are moving while transmitting?

A.A. Flip-floppingFlip-flopping

B.B. Picket fencingPicket fencing

C.C. Frequency shiftingFrequency shifting

D.D. PulsingPulsing


T3A06 What term is commonly used to T3A06 What term is commonly used to describe the rapid fluttering sound sometimes describe the rapid fluttering sound sometimes heard from mobile stations that are moving heard from mobile stations that are moving while transmitting?while transmitting?

A.A. Flip-floppingFlip-flopping

B.B. Picket fencingPicket fencingC.C. Frequency shiftingFrequency shifting

D.D. PulsingPulsing


T3A07 What type of wave carries radio T3A07 What type of wave carries radio signals between transmitting and receiving signals between transmitting and receiving stations?stations?

A.A. ElectromagneticElectromagnetic

B.B. ElectrostaticElectrostatic

C.C. Surface acousticSurface acoustic

D.D. MagnetostrictiveMagnetostrictive


T3A07 What type of wave carries radio T3A07 What type of wave carries radio signals between transmitting and receiving signals between transmitting and receiving stations?stations?

A.A. ElectromagneticElectromagneticB.B. ElectrostaticElectrostatic

C.C. Surface acousticSurface acoustic

D.D. MagnetostrictiveMagnetostrictive


T3A08 What is the cause of irregular T3A08 What is the cause of irregular fading of signals from distant stations fading of signals from distant stations during times of generally good reception?during times of generally good reception?

A.A. Absorption of signals by the "D" layer of the Absorption of signals by the "D" layer of the ionosphereionosphere

B.B. Absorption of signals by the "E" layer of the ionosphereAbsorption of signals by the "E" layer of the ionosphere

C.C. Random combining of signals arriving via different path Random combining of signals arriving via different path lengthslengths

D.D. Intermodulation distortion in the local receiverIntermodulation distortion in the local receiver


T3A08 What is the cause of irregular fading of T3A08 What is the cause of irregular fading of signals from distant stations during times of signals from distant stations during times of generally good reception?generally good reception?

A.A. Absorption of signals by the "D" layer of the Absorption of signals by the "D" layer of the ionosphereionosphere

B.B. Absorption of signals by the "E" layer of the ionosphereAbsorption of signals by the "E" layer of the ionosphere

C.C. Random combining of signals arriving via Random combining of signals arriving via different path lengthsdifferent path lengthsD.D. Intermodulation distortion in the local receiverIntermodulation distortion in the local receiver


T3A09 Which of the following is a common T3A09 Which of the following is a common effect of "skip" reflections between the effect of "skip" reflections between the Earth and the ionosphere?Earth and the ionosphere?

A.A. The sidebands become reversed at each reflectionThe sidebands become reversed at each reflection

B.B. The polarization of the original signal is randomizedThe polarization of the original signal is randomized

C.C. The apparent frequency of the received signal is The apparent frequency of the received signal is shifted by a random amountshifted by a random amount

D.D. Signals at frequencies above 30 MHz become stronger Signals at frequencies above 30 MHz become stronger with each reflectionwith each reflection


T3A09 Which of the following is a common T3A09 Which of the following is a common effect of "skip" reflections between the Earth effect of "skip" reflections between the Earth and the ionosphere?and the ionosphere?

A.A. The sidebands become reversed at each reflectionThe sidebands become reversed at each reflection

B.B. The polarization of the original signal is The polarization of the original signal is randomizedrandomizedC.C. The apparent frequency of the received signal is The apparent frequency of the received signal is

shifted by a random amountshifted by a random amount

D.D. Signals at frequencies above 30 MHz become stronger Signals at frequencies above 30 MHz become stronger with each reflectionwith each reflection


T3A10 What may occur if VHF or UHF data T3A10 What may occur if VHF or UHF data signals propagate over multiple paths?signals propagate over multiple paths?

A.A. Transmission rates can be increased by a factor equal Transmission rates can be increased by a factor equal to the number of separate paths observedto the number of separate paths observed

B.B. Transmission rates must be decreased by a factor Transmission rates must be decreased by a factor equal to the number of separate paths observedequal to the number of separate paths observed

C.C. No significant changes will occur if the signals are No significant changes will occur if the signals are transmitting using FMtransmitting using FM

D.D. Error rates are likely to increaseError rates are likely to increase


T3A11 Which part of the atmosphere T3A11 Which part of the atmosphere enables the propagation of radio signals enables the propagation of radio signals around the world?around the world?

A.A. The stratosphereThe stratosphere

B.B. The troposphereThe troposphere

C.C. The ionosphereThe ionosphere

D.D. The magnetosphereThe magnetosphere

Radio Wave Propagation24

Ionospheric LayersIonospheric Layers


T3A11 Which part of the atmosphere enables T3A11 Which part of the atmosphere enables the propagation of radio signals around the the propagation of radio signals around the world?world?

A.A. The stratosphereThe stratosphere

B.B. The troposphereThe troposphere

C.C. The ionosphereThe ionosphereD.D. The magnetosphereThe magnetosphere

Radio and Electronic Fundamentals26

Wavelength vs FrequencyWavelength vs Frequency

The distance a radio wave travels in one cycle is called wavelength

The number of cycles per second is frequency

The maximum displacement of wave from reference value is amplitude

One WavelengthOne Wavelength

TimeTime

V+V+

VV--

0V0V

One CycleOne Cycle AmplitudeAmplitude


T3B01 What is the name for the distance a T3B01 What is the name for the distance a radio wave travels during one complete radio wave travels during one complete cycle?cycle?

A.A. Wave speedWave speed

B.B. WaveformWaveform

C.C. WavelengthWavelength

D.D. Wave spreadWave spread


T3B01 What is the name for the distance a T3B01 What is the name for the distance a radio wave travels during one complete cycle?radio wave travels during one complete cycle?

A.A. Wave speedWave speed

B.B. WaveformWaveform

C.C. WavelengthWavelengthD.D. Wave spreadWave spread


T3B02 What term describes the number of T3B02 What term describes the number of times per second that an alternating times per second that an alternating current reverses direction?current reverses direction?

A.A. Pulse ratePulse rate

B.B. SpeedSpeed


D.D. FrequencyFrequency


T3B02 What term describes the number of T3B02 What term describes the number of times per second that an alternating current times per second that an alternating current reverses direction?reverses direction?

A.A. Pulse ratePulse rate

B.B. SpeedSpeed


D.D. FrequencyFrequency


T3B03 What are the two components of a T3B03 What are the two components of a radio wave?radio wave?

A.A. AC and DCAC and DC

B.B. Voltage and currentVoltage and current

C.C. Electric and magnetic fieldsElectric and magnetic fields

D.D. Ionizing and non-ionizing radiationIonizing and non-ionizing radiation


T3B03 What are the two components of a T3B03 What are the two components of a radio wave?radio wave?

A.A. AC and DCAC and DC

B.B. Voltage and currentVoltage and current

C.C. Electric and magnetic fieldsElectric and magnetic fieldsD.D. Ionizing and non-ionizing radiationIonizing and non-ionizing radiation


T3B04 How fast does a radio wave travel T3B04 How fast does a radio wave travel through free space?through free space?

A.A. At the speed of lightAt the speed of light

B.B. At the speed of soundAt the speed of sound

C.C. Its speed is inversely proportional to its wavelengthIts speed is inversely proportional to its wavelength

D.D. Its speed increases as the frequency increasesIts speed increases as the frequency increases


T3B04 How fast does a radio wave travel T3B04 How fast does a radio wave travel through free space?through free space?

A.A. At the speed of lightAt the speed of lightB.B. At the speed of soundAt the speed of sound

C.C. Its speed is inversely proportional to its wavelengthIts speed is inversely proportional to its wavelength

D.D. Its speed increases as the frequency increasesIts speed increases as the frequency increases

Radio and Electronic Fundamentals35

300300Freq (Freq (MHzMHz))Wavelength =Wavelength =

Frequency to Wavelength ConversionFrequency to Wavelength Conversion

To convert from frequency to wavelength in meters:To convert from frequency to wavelength in meters:

Frequency and wavelength are inversely proportional – as one increases, the other decreases

Longer (wavelength) – Lower (frequency)


T3B05 How does the wavelength of a radio T3B05 How does the wavelength of a radio wave relate to its frequency?wave relate to its frequency?

A.A. The wavelength gets longer as the frequency The wavelength gets longer as the frequency increasesincreases

B.B. The wavelength gets shorter as the frequency The wavelength gets shorter as the frequency increasesincreases

C.C. There is no relationship between wavelength and There is no relationship between wavelength and frequencyfrequency

D.D. The wavelength depends on the bandwidth of the The wavelength depends on the bandwidth of the signalsignal


T3B05 How does the wavelength of a radio T3B05 How does the wavelength of a radio wave relate to its frequency?wave relate to its frequency?

A.A. The wavelength gets longer as the frequency The wavelength gets longer as the frequency increasesincreases

B.B. The wavelength gets shorter as the The wavelength gets shorter as the frequency increasesfrequency increasesC.C. There is no relationship between wavelength and There is no relationship between wavelength and

frequencyfrequency

D.D. The wavelength depends on the bandwidth of the The wavelength depends on the bandwidth of the signalsignal


T3B06 What is the formula for converting T3B06 What is the formula for converting frequency to wavelength in meters?frequency to wavelength in meters?

A.A. Wavelength in meters equals frequency in hertz Wavelength in meters equals frequency in hertz multiplied by 300multiplied by 300

B.B. Wavelength in meters equals frequency in hertz Wavelength in meters equals frequency in hertz divided by 300divided by 300

C.C. Wavelength in meters equals frequency in megahertz Wavelength in meters equals frequency in megahertz divided by 300divided by 300

D.D. Wavelength in meters equals 300 divided by frequency Wavelength in meters equals 300 divided by frequency in megahertzin megahertz


T3B06 What is the formula for converting T3B06 What is the formula for converting frequency to wavelength in meters?frequency to wavelength in meters?

A.A. Wavelength in meters equals frequency in hertz Wavelength in meters equals frequency in hertz multiplied by 300multiplied by 300

B.B. Wavelength in meters equals frequency in hertz Wavelength in meters equals frequency in hertz divided by 300divided by 300

C.C. Wavelength in meters equals frequency in megahertz Wavelength in meters equals frequency in megahertz divided by 300divided by 300

D.D. Wavelength in meters equals 300 divided Wavelength in meters equals 300 divided by frequency in megahertzby frequency in megahertz


T3B07 What property of radio waves is T3B07 What property of radio waves is often used to identify the different often used to identify the different frequency bands?frequency bands?

A.A. The approximate wavelengthThe approximate wavelength

B.B. The magnetic intensity of wavesThe magnetic intensity of waves

C.C. The time it takes for waves to travel one mileThe time it takes for waves to travel one mile

D.D. The voltage standing wave ratio of wavesThe voltage standing wave ratio of waves


T3B07 What property of radio waves is often T3B07 What property of radio waves is often used to identify the different frequency bands?used to identify the different frequency bands?

A.A. The approximate wavelengthThe approximate wavelengthB.B. The magnetic intensity of wavesThe magnetic intensity of waves

C.C. The time it takes for waves to travel one mileThe time it takes for waves to travel one mile

D.D. The voltage standing wave ratio of wavesThe voltage standing wave ratio of waves

Radio and Electronic Fundamentals 42

Radio SpectrumRadio Spectrum

Medium WaveMedium Wave

(MF)(MF)Short WaveShort Wave

(HF)(HF)

Very High Very High FrequencyFrequency

(VHF)(VHF)

Ultra High Ultra High FrequencyFrequency

(UHF)(UHF)

AM

Bro

adca

st5

40

16

30

TV

2-6

54

88

FM

Bro

adca

st1

08

TV

7-1

31

74

21

6

TV

14-

694

70

80

6

300 kHz 3 MHz 30 MHz 300 MHz 3 GHzFrequency

1 Km 100 m 10 m 1 m 10 cmWavelength

Major Amateur Bands in Amber


T3B08 What are the frequency limits of the T3B08 What are the frequency limits of the VHF spectrum?VHF spectrum?

A.A. 30 to 300 kHz30 to 300 kHz

B.B. 30 to 300 MHz30 to 300 MHz

C.C. 300 to 3000 kHz300 to 3000 kHz

D.D. 300 to 3000 MHz300 to 3000 MHz


T3B08 What are the frequency limits of the T3B08 What are the frequency limits of the VHF spectrum?VHF spectrum?

A.A. 30 to 300 kHz30 to 300 kHz

B.B. 30 to 300 MHz30 to 300 MHzC.C. 300 to 3000 kHz300 to 3000 kHz

D.D. 300 to 3000 MHz300 to 3000 MHz


T3B09 What are the frequency limits of the T3B09 What are the frequency limits of the UHF spectrum?UHF spectrum?

A.A. 30 to 300 kHz30 to 300 kHz

B.B. 30 to 300 MHz30 to 300 MHz

C.C. 300 to 3000 kHz300 to 3000 kHz

D.D. 300 to 3000 MHz300 to 3000 MHz


T3B10 What frequency range is referred to T3B10 What frequency range is referred to as HF?as HF?

A.A. 300 to 3000 MHz300 to 3000 MHz

B.B. 30 to 300 MHz30 to 300 MHz

C.C. 3 to 30 MHz3 to 30 MHz

D.D. 300 to 3000 kHz300 to 3000 kHz


T3B10 What frequency range is referred to as T3B10 What frequency range is referred to as HF?HF?

A.A. 300 to 3000 MHz300 to 3000 MHz

B.B. 30 to 300 MHz30 to 300 MHz

C.C. 3 to 30 MHz3 to 30 MHzD.D. 300 to 3000 kHz300 to 3000 kHz


T3B11 What is the approximate velocity of T3B11 What is the approximate velocity of a radio wave as it travels through free a radio wave as it travels through free space?space?

A.A. 3000 kilometers per second3000 kilometers per second

B.B. 300,000,000 meters per second300,000,000 meters per second

C.C. 300,000 miles per hour300,000 miles per hour

D.D. 186,000 miles per hour186,000 miles per hour


T3B11 What is the approximate velocity of a T3B11 What is the approximate velocity of a radio wave as it travels through free space?radio wave as it travels through free space?

A.A. 3000 kilometers per second3000 kilometers per second

B.B. 300,000,000 meters per second300,000,000 meters per secondC.C. 300,000 miles per hour300,000 miles per hour

D.D. 186,000 miles per hour186,000 miles per hour


T3C01 Why are "direct" (not via a repeater) T3C01 Why are "direct" (not via a repeater) UHF signals rarely heard from stations UHF signals rarely heard from stations outside your local coverage area?outside your local coverage area?

A.A. They are too weak to go very farThey are too weak to go very far

B.B. FCC regulations prohibit them from going more than FCC regulations prohibit them from going more than 50 miles50 miles

C.C. UHF signals are usually not reflected by the UHF signals are usually not reflected by the ionosphereionosphere

D.D. They collide with trees and shrubbery and fade outThey collide with trees and shrubbery and fade out


T3C01 Why are "direct" (not via a repeater) T3C01 Why are "direct" (not via a repeater) UHF signals rarely heard from stations UHF signals rarely heard from stations outside your local coverage area?outside your local coverage area?

A.A. They are too weak to go very farThey are too weak to go very far

B.B. FCC regulations prohibit them from going more than FCC regulations prohibit them from going more than 50 miles50 miles

C.C. UHF signals are usually not reflected by UHF signals are usually not reflected by the ionospherethe ionosphereD.D. They collide with trees and shrubbery and fade outThey collide with trees and shrubbery and fade out


T3C02 Which of the following might be T3C02 Which of the following might be happening when VHF signals are being happening when VHF signals are being received from long distances?received from long distances?

A.A. Signals are being reflected from outer spaceSignals are being reflected from outer space

B.B. Signals are arriving by sub-surface ductingSignals are arriving by sub-surface ducting

C.C. Signals are being reflected by lightning storms in your Signals are being reflected by lightning storms in your areaarea

D.D. Signals are being refracted from a sporadic E layerSignals are being refracted from a sporadic E layer


T3C02 Which of the following might be T3C02 Which of the following might be happening when VHF signals are being happening when VHF signals are being received from long distances?received from long distances?

A.A. Signals are being reflected from outer spaceSignals are being reflected from outer space

B.B. Signals are arriving by sub-surface ductingSignals are arriving by sub-surface ducting

C.C. Signals are being reflected by lightning storms in your Signals are being reflected by lightning storms in your areaarea

D.D. Signals are being refracted from a Signals are being refracted from a sporadic E layersporadic E layer


T3C03 What is a characteristic of VHF T3C03 What is a characteristic of VHF signals received via auroral reflection?signals received via auroral reflection?

A.A. Signals from distances of 10,000 or more miles are Signals from distances of 10,000 or more miles are commoncommon

B.B. The signals exhibit rapid fluctuations of strength and The signals exhibit rapid fluctuations of strength and often sound distortedoften sound distorted

C.C. These types of signals occur only during winter These types of signals occur only during winter nighttime hoursnighttime hours

D.D. These types of signals are generally strongest when These types of signals are generally strongest when your antenna is aimed to the south (for stations in the your antenna is aimed to the south (for stations in the Northern Hemisphere)Northern Hemisphere)


T3C03 What is a characteristic of VHF signals T3C03 What is a characteristic of VHF signals received via auroral reflection?received via auroral reflection?

A.A. Signals from distances of 10,000 or more miles are Signals from distances of 10,000 or more miles are commoncommon

B.B. The signals exhibit rapid fluctuations of The signals exhibit rapid fluctuations of strength and often sound distortedstrength and often sound distortedC.C. These types of signals occur only during winter These types of signals occur only during winter

nighttime hoursnighttime hours

D.D. These types of signals are generally strongest when These types of signals are generally strongest when your antenna is aimed to the south (for stations in the your antenna is aimed to the south (for stations in the Northern Hemisphere)Northern Hemisphere)


T3C04 Which of the following propagation T3C04 Which of the following propagation types is most commonly associated with types is most commonly associated with occasional strong over-the-horizon signals occasional strong over-the-horizon signals on the 10, 6, and 2 meter bands?on the 10, 6, and 2 meter bands?

A.A. BackscatterBackscatter

B.B. Sporadic ESporadic E

C.C. D layer absorptionD layer absorption

D.D. Gray-line propagationGray-line propagation


T3C04 Which of the following propagation T3C04 Which of the following propagation types is most commonly associated with types is most commonly associated with occasional strong over-the-horizon signals on occasional strong over-the-horizon signals on the 10, 6, and 2 meter bands?the 10, 6, and 2 meter bands?

A.A. BackscatterBackscatter

B.B. Sporadic ESporadic EC.C. D layer absorptionD layer absorption

D.D. Gray-line propagationGray-line propagation


T3C05 What is meant by the term "knife-T3C05 What is meant by the term "knife-edge" propagation?edge" propagation?

A.A. Signals are reflected back toward the originating Signals are reflected back toward the originating station at acute anglesstation at acute angles

B.B. Signals are sliced into several discrete beams and Signals are sliced into several discrete beams and arrive via different pathsarrive via different paths

C.C. Signals are partially refracted around solid objects Signals are partially refracted around solid objects exhibiting sharp edgesexhibiting sharp edges

D.D. Signals propagated close to the band edge exhibiting a Signals propagated close to the band edge exhibiting a sharp cutoffsharp cutoff


T3C05 What is meant by the term "knife-T3C05 What is meant by the term "knife-edge" propagation?edge" propagation?

A.A. Signals are reflected back toward the originating Signals are reflected back toward the originating station at acute anglesstation at acute angles

B.B. Signals are sliced into several discrete beams and Signals are sliced into several discrete beams and arrive via different pathsarrive via different paths

C.C. Signals are partially refracted around Signals are partially refracted around solid objects exhibiting sharp edgessolid objects exhibiting sharp edgesD.D. Signals propagated close to the band edge exhibiting a Signals propagated close to the band edge exhibiting a

sharp cutoffsharp cutoff


T3C06 What mode is responsible for T3C06 What mode is responsible for allowing over-the-horizon VHF and UHF allowing over-the-horizon VHF and UHF communications to ranges of communications to ranges of approximately 300 miles on a regular approximately 300 miles on a regular basis?basis?

A.A. Tropospheric scatterTropospheric scatter

B.B. D layer refractionD layer refraction

C.C. F2 layer refractionF2 layer refraction

D.D. Faraday rotationFaraday rotation


T3C06 What mode is responsible for allowing T3C06 What mode is responsible for allowing over-the-horizon VHF and UHF over-the-horizon VHF and UHF communications to ranges of approximately communications to ranges of approximately 300 miles on a regular basis?300 miles on a regular basis?

A.A. Tropospheric scatterTropospheric scatterB.B. D layer refractionD layer refraction

C.C. F2 layer refractionF2 layer refraction

D.D. Faraday rotationFaraday rotation


T3C07 What band is best suited to T3C07 What band is best suited to communicating via meteor scatter?communicating via meteor scatter?

A.A. 10 meters10 meters

B.B. 6 meters6 meters

C.C. 2 meters2 meters

D.D. 70 cm70 cm


T3C07 What band is best suited to T3C07 What band is best suited to communicating via meteor scatter?communicating via meteor scatter?

A.A. 10 meters10 meters

B.B. 6 meters6 metersC.C. 2 meters2 meters

D.D. 70 cm70 cm


T3C08 What causes "tropospheric T3C08 What causes "tropospheric ducting"?ducting"?

A.A. Discharges of lightning during electrical stormsDischarges of lightning during electrical storms

B.B. Sunspots and solar flaresSunspots and solar flares

C.C. Updrafts from hurricanes and tornadoesUpdrafts from hurricanes and tornadoes

D.D. Temperature inversions in the atmosphereTemperature inversions in the atmosphere


T3C08 What causes "tropospheric ducting"?T3C08 What causes "tropospheric ducting"?

A.A. Discharges of lightning during electrical stormsDischarges of lightning during electrical storms

B.B. Sunspots and solar flaresSunspots and solar flares

C.C. Updrafts from hurricanes and tornadoesUpdrafts from hurricanes and tornadoes

D.D. Temperature inversions in the Temperature inversions in the atmosphereatmosphere


T3C09 What is generally the best time for T3C09 What is generally the best time for long-distance 10 meter band propagation?long-distance 10 meter band propagation?

A.A. During daylight hoursDuring daylight hours

B.B. During nighttime hoursDuring nighttime hours

C.C. When there are coronal mass ejectionsWhen there are coronal mass ejections

D.D. Whenever the solar flux is lowWhenever the solar flux is low


T3C09 What is generally the best time for T3C09 What is generally the best time for long-distance 10 meter band propagation?long-distance 10 meter band propagation?

A.A. During daylight hoursDuring daylight hoursB.B. During nighttime hoursDuring nighttime hours

C.C. When there are coronal mass ejectionsWhen there are coronal mass ejections

D.D. Whenever the solar flux is lowWhenever the solar flux is low


T3C10 What is the radio horizon?T3C10 What is the radio horizon?

A.A. The distance at which radio signals between two points The distance at which radio signals between two points are effectively blocked by the curvature of the Earthare effectively blocked by the curvature of the Earth

B.B. The distance from the ground to a horizontally The distance from the ground to a horizontally mounted antennamounted antenna

C.C. The farthest point you can see when standing at the The farthest point you can see when standing at the base of your antenna towerbase of your antenna tower

D.D. The shortest distance between two points on the The shortest distance between two points on the Earth's surfaceEarth's surface


T3C10 What is the radio horizon?T3C10 What is the radio horizon?

A.A. The distance at which radio signals The distance at which radio signals between two points are effectively blocked by between two points are effectively blocked by the curvature of the Earththe curvature of the EarthB.B. The distance from the ground to a horizontally The distance from the ground to a horizontally

mounted antennamounted antenna

C.C. The farthest point you can see when standing at the The farthest point you can see when standing at the base of your antenna towerbase of your antenna tower

D.D. The shortest distance between two points on the The shortest distance between two points on the Earth's surfaceEarth's surface


T3C11 Why do VHF and UHF radio signals T3C11 Why do VHF and UHF radio signals usually travel somewhat farther than the usually travel somewhat farther than the visual line of sight distance between two visual line of sight distance between two stations?stations?

A.A. Radio signals move somewhat faster than the speed of Radio signals move somewhat faster than the speed of lightlight

B.B. Radio waves are not blocked by dust particlesRadio waves are not blocked by dust particles

C.C. The Earth seems less curved to radio waves than to The Earth seems less curved to radio waves than to lightlight

D.D. Radio waves are blocked by dust particlesRadio waves are blocked by dust particles


T3C11 Why do VHF and UHF radio signals T3C11 Why do VHF and UHF radio signals usually travel somewhat farther than the usually travel somewhat farther than the visual line of sight distance between two visual line of sight distance between two stations?stations?

A.A. Radio signals move somewhat faster than the speed of Radio signals move somewhat faster than the speed of lightlight

B.B. Radio waves are not blocked by dust particlesRadio waves are not blocked by dust particles

C.C. The Earth seems less curved to radio The Earth seems less curved to radio waves than to lightwaves than to lightD.D. Radio waves are blocked by dust particlesRadio waves are blocked by dust particles


SUBELEMENT T3SUBELEMENT T3[3 exam questions – 3 groups][3 exam questions – 3 groups]

subelement t3 [3 exam questions - 3 groups] radio wave characteristics, radio and electromagnetic...

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