Canadian Basic Qualification pool, section B-007-001

Subelement B-007

B-007

Section B-007-001

B-007-001-001

What type of wave propagation usually occurs between two nearby VHF transceivers?

A.
Ionospheric
Correct Answer
B.
Line-of-sight
C.
Auroral
D.
Ducting

B-007-001-001

Key words: VHF, NEARBY. The two antennas "see" one another. 'Line-of-sight' is also known as 'direct waves' in contrast with 'sky waves'.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

B-007-001-002

What does near vertical incidence sky-wave (NVIS) propagation enable?

A.
Multi-hop HF worldwide communications
B.
Regional communications above the critical frequency
Correct Answer
C.
Medium range HF communications, especially in difficult terrain
D.
Continent-wide communications

B-007-001-002

Ground wave propagation present on long wavelengths (e.g., 160 m and 80 m) is of the order of 200 km. One hop via the E layer of the ionosphere can reach 2000 km. One hop via the F2 layer can reach 4000 km. Multiple hops cover greater distances. Near vertical incidence sky-wave (NVIS) propagation reaches beyond the ground wave into the skip zone.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

B-007-001-003

When a signal is returned to Earth by the ionosphere, what is this called?

Correct Answer
A.
Sky-wave propagation
B.
Earth-Moon-Earth propagation
C.
Ground-wave propagation
D.
Tropospheric propagation

B-007-001-003

Sky Waves or 'ionospheric waves' rely on refraction in layers of the ionosphere.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

B-007-001-004

On VHF and higher frequencies, why does the radio horizon extend beyond the visible horizon?

A.
Diffraction caused by soil conductivity
Correct Answer
B.
Normal refraction in the troposphere
C.
Ionization in the troposphere
D.
Refraction in the D-region

B-007-001-004

The radio horizon is about 15% further than the visible horizon. The troposphere is the lower part of the atmosphere where we live. Temperature, pressure and water vapour content change gradually with altitude. Hence, the refractive index changes with altitude and leads to the refraction of radio waves. Masses about the size of a wavelength with small differences in temperature, pressure and water vapour content are also found here and there in the troposphere. These masses provoke another effect, namely, tropospheric scatter (troposcatter).

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

B-007-001-005

What type of wave is commonly known as sky wave?

A.
Space wave
B.
Scattered wave
Correct Answer
C.
Ionospheric wave
D.
Tropospheric wave

B-007-001-005

Sky Waves or 'ionospheric waves' rely on refraction in layers of the ionosphere.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

B-007-001-006

What portion of a radio signal is directly affected by the surface of the Earth?

A.
Tropospheric wave
B.
Ionospheric wave
C.
Scattered wave
Correct Answer
D.
Ground wave

B-007-001-006

Key words: SURFACE OF THE EARTH. "A special form of diffraction. Bending results when the lower part of the wave front loses energy due to currents induced in the ground (ARRL Handbook)". Ground Wave propagation present on long wavelengths (e.g., 160 m and 80 m) is of the order of 200 km.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

B-007-001-007

What makes radiocommunication out to 200 km possible at lower HF frequencies during the daytime?

A.
Space wave
B.
Tropospheric ducting
C.
Skip wave
Correct Answer
D.
Ground wave

B-007-001-007

"A ground wave is the result of a special form of diffraction that primarily affects longer wavelength vertically polarized radio waves. It is most apparent in the 80 and 160-metre amateur bands, where practical ground-wave distances may extend beyond 200 km. It is also the primary mechanism used by AM broadcast stations in the medium-wave bands. The term ground wave is often mistakenly applied to any short-distance communication, but the actual mechanism is unique to the longer-wave bands. (...) Ground wave is most useful during the day at 1.8 and 3.5 MHz, when D layer absorption makes sky wave propagation more difficult." (ARRL Handbook 2012).

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

B-007-001-008

Considering the bands from 160 metres to 6 metres, which band offers the greatest ground-wave propagation distance?

Correct Answer
A.
160 metres
B.
6 metres
C.
40 metres
D.
10 metres

B-007-001-008

"The actual mechanism is unique to longer wavelengths (ARRL Handbook)". Ground Wave (about 200 km) is most apparent on 160 m and 80 m. "A special form of diffraction. Bending results when the lower part of the wave front loses energy due to currents induced in the ground (ARRL Handbook)".

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

B-007-001-009

What type of radio wave follows a path from the transmitter to the ionosphere and back to Earth?

Correct Answer
A.
Sky wave
B.
Plane wave
C.
Scattered wave
D.
Direct wave

B-007-001-009

Key word: IONOSPHERE. Sky Waves or 'ionospheric waves' rely on refraction in layers of the ionosphere.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

B-007-001-010

Reception of high frequency (HF) radio waves beyond 4000 km is generally made possible by:

A.
space wave
Correct Answer
B.
ionospheric wave
C.
ground wave
D.
scattered wave

B-007-001-010

One hop via the E layer of the ionosphere can reach 2000 km. One hop via the F2 layer can reach 4000 km. Multiple hops cover greater distances.

Original copyright; explanations transcribed with permission from Francois VE2AAY, author of the ExHAMiner exam simulator. Do not copy without his permission.

Tags: none

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