Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Amateur Radio - Extra > E3 - RADIO WAVE PROPAGATION [3 Exam Questions - 3 Groups] > Flashcards

E3 - RADIO WAVE PROPAGATION [3 Exam Questions - 3 Groups] Flashcards

1
Q

What is the approximate maximum separation measured along the surface of the Earth between two stations communicating by Moon bounce?

A. 500 miles, if the Moon is at perigee

B. 2000 miles, if the Moon is at apogee

C. 5000 miles, if the Moon is at perigee

D. 12,000 miles, as long as both can “see” the Moon

A

D. 12,000 miles, as long as both can “see” the Moon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What characterizes libration fading of an Earth-Moon-Earth signal?

A. A slow change in the pitch of the CW signal

B. A fluttery irregular fading

C. A gradual loss of signal as the Sun rises

D. The returning echo is several Hertz lower in frequency than the transmitted signal

A

B. A fluttery irregular fading

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

When scheduling EME contacts, which of these conditions will generally result in the least path loss?

A. When the Moon is at perigee

B. When the Moon is full

C. When the Moon is at apogee

D. When the MUF is above 30 MHz

A

A. When the Moon is at perigee

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What type of receiving system is desirable for EME communications?

A. Equipment with very wide bandwidth

B. Equipment with very low dynamic range

C. Equipment with very low gain

D. Equipment with very low noise figures

A

D. Equipment with very low noise figures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Which of the following describes a method of establishing EME contacts?

A. Time synchronous transmissions with each station alternating

B. Storing and forwarding digital messages

C. Judging optimum transmission times by monitoring beacons from the Moon

D. High speed CW identification to avoid fading

A

A. Time synchronous transmissions with each station alternating

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What frequency range would you normally tune to find EME signals in the 2 meter band?

A. 144.000 - 144.001 MHz

B. 144.000 - 144.100 MHz

C. 144.100 - 144.300 MHz

D. 145.000 - 145.100 MHz

A

B. 144.000 - 144.100 MHz

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What frequency range would you normally tune to find EME signals in the 70 cm band?

A. 430.000 - 430.150 MHz

B. 430.100 - 431.100 MHz

C. 431.100 - 431.200 MHz

D. 432.000 - 432.100 MHz

A

D. 432.000 - 432.100 MHz

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

When a meteor strikes the Earth’s atmosphere, a cylindrical region of free electrons is formed at what layer of the ionosphere?

A. The E layer

B. The F1 layer

C. The F2 layer

D. The D layer

A

A. The E layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Which of the following frequency ranges is well suited for meteor-scatter communications?

A. 1.8 - 1.9 MHz

B. 10 - 14 MHz

C. 28 - 148 MHz

D. 220 - 450 MHz

A

C. 28 - 148 MHz

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Which of the following is a good technique for making meteor-scatter contacts?

A. 15 second timed transmission sequences with stations alternating based on location

B. Use of high speed CW or digital modes

C. Short transmission with rapidly repeated call signs and signal reports

D. All of these choices are correct

A

D. All of these choices are correct

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is transequatorial propagation?

A. Propagation between two mid-latitude points at approximately the same distance north and south of the magnetic equator

B. Propagation between any two points located on the magnetic equator

C. Propagation between two continents by way of ducts along the magnetic equator

D. Propagation between two stations at the same latitude

A

A. Propagation between two mid-latitude points at approximately the same distance north and south of the magnetic equator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the approximate maximum range for signals using transequatorial propagation?

A. 1000 miles

B. 2500 miles

C. 5000 miles

D. 7500 miles

A

C. 5000 miles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the best time of day for transequatorial propagation?

A. Morning

B. Noon

C. Afternoon or early evening

D. Late at night

A

C. Afternoon or early evening

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What type of propagation is probably occurring if an HF beam antenna must be pointed in a direction 180 degrees away from a station to receive the strongest signals?

A. Long-path

B. Sporadic-E

C. Transequatorial

D. Auroral

A

A. Long-path

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which amateur bands typically support long-path propagation?

A. 160 to 40 meters

B. 30 to 10 meters

C. 160 to 10 meters

D. 6 meters to 2 meters

A

C. 160 to 10 meters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Which of the following amateur bands most frequently provides long-path propagation?

A. 80 meters

B. 20 meters

C. 10 meters

D. 6 meters

A

B. 20 meters

17
Q

Which of the following could account for hearing an echo on the received signal of a distant station?

A. High D layer absorption

B. Meteor scatter

C. Transmit frequency is higher than the MUF

D. Receipt of a signal by more than one path

A

D. Receipt of a signal by more than one path

18
Q

What type of HF propagation is probably occurring if radio signals travel along the terminator between daylight and darkness?

A. Transequatorial

B. Sporadic-E

C. Long-path

D. Gray-line

A

D. Gray-line

19
Q

At what time of day is gray-line propagation most likely to occur?

A. At sunrise and sunset

B. When the Sun is directly above the location of the transmitting station

C. When the Sun is directly overhead at the middle of the communications path between the two stations

D. When the Sun is directly above the location of the receiving station

A

A. At sunrise and sunset

20
Q

What is the cause of gray-line propagation?

A. At midday, the Sun being directly overhead superheats the ionosphere causing increased refraction of radio waves

B. At twilight, D-layer absorption drops while E-layer and F-layer propagation remain strong

C. In darkness, solar absorption drops greatly while atmospheric ionization remains steady

D. At mid afternoon, the Sun heats the ionosphere decreasing radio wave refraction and the MUF

A

B. At twilight, D-layer absorption drops while E-layer and F-layer propagation remain strong

21
Q

Which of the following describes gray-line propagation?

A. Backscatter contacts on the 10 meter band

B. Over the horizon propagation on the 6 and 2 meter bands

C. Long distance communications at twilight on frequencies less than 15 MHz

D. Tropospheric propagation on the 2 meter and 70 centimeter bands

A

C. Long distance communications at twilight on frequencies less than 15 MHz

22
Q

Which of the following effects does Aurora activity have on radio communications?

A. SSB signals are raspy

B. Signals propagating through the Aurora are fluttery

C. CW signals appear to be modulated by white noise

D. All of these choices are correct

A

D. All of these choices are correct

23
Q

What is the cause of Aurora activity?

A. The interaction between the solar wind and the Van Allen belt

B. A low sunspot level combined with tropospheric ducting

C. The interaction of charged particles from the Sun with the Earth’s magnetic field and the ionosphere

D. Meteor showers concentrated in the northern latitudes

A

C. The interaction of charged particles from the Sun with the Earth’s magnetic field and the ionosphere

24
Q

Where in the ionosphere does Aurora activity occur?

A. In the F1-region

B. In the F2-region

C. In the D-region

D. In the E-region

A

D. In the E-region

25
Q

Which emission mode is best for Aurora propagation?

A. CW

B. SSB

C. FM

D. RTTY

A

A. CW

26
Q

Which of the following describes selective fading?

A. Variability of signal strength with beam heading

B. Partial cancellation of some frequencies within the received pass band

C. Sideband inversion within the ionosphere

D. Degradation of signal strength due to backscatter

A

B. Partial cancellation of some frequencies within the received pass band

27
Q

By how much does the VHF/UHF radio-path horizon distance exceed the geometric horizon?

A. By approximately 15% of the distance

B. By approximately twice the distance

C. By approximately one-half the distance

D. By approximately four times the distance

A

A. By approximately 15% of the distance

28
Q

How does the radiation pattern of a horizontally polarized 3-element beam antenna vary with its height above ground?

A. The main lobe takeoff angle increases with increasing height

B. The main lobe takeoff angle decreases with increasing height

C. The horizontal beam width increases with height

D. The horizontal beam width decreases with height

A

B. The main lobe takeoff angle decreases with increasing height

29
Q

What is the name of the high-angle wave in HF propagation that travels for some distance within the F2 region?

A. Oblique-angle ray

B. Pedersen ray

C. Ordinary ray

D. Heaviside ray

A

B. Pedersen ray

30
Q

Which of the following is usually responsible for causing VHF signals to propagate for hundreds of miles?

A. D-region absorption

B. Faraday rotation

C. Tropospheric ducting

D. Ground wave

A

C. Tropospheric ducting

31
Q

How does the performance of a horizontally polarized antenna mounted on the side of a hill compare with the same antenna mounted on flat ground?

A. The main lobe takeoff angle increases in the downhill direction

B. The main lobe takeoff angle decreases in the downhill direction

C. The horizontal beam width decreases in the downhill direction

D. The horizontal beam width increases in the uphill direction

A

B. The main lobe takeoff angle decreases in the downhill direction

32
Q

From the contiguous 48 states, in which approximate direction should an antenna be pointed to take maximum advantage of aurora propagation?

A. South

B. North

C. East

D. West

A

B. North

33
Q

How does the maximum distance of ground-wave propagation change when the signal frequency is increased?

A. It stays the same

B. It increases

C. It decreases

D. It peaks at roughly 14 MHz

A

C. It decreases

34
Q

What type of polarization is best for ground-wave propagation?

A. Vertical

B. Horizontal

C. Circular

D. Elliptical

A

A. Vertical

35
Q

Why does the radio-path horizon distance exceed the geometric horizon?

A. E-region skip

B. D-region skip

C. Downward bending due to aurora refraction

D. Downward bending due to density variations in the atmosphere

A

D. Downward bending due to density variations in the atmosphere

Amateur Radio - Extra (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions