Canadian Basic Qualification pool, section B-003-020

Subelement B-003

B-003

Section B-003-020

B-003-020-001

Why should you ground all antenna and rotator cables when your station is not in use?

A.
To prevent unauthorized persons from using the station
Correct Answer
B.
To help protect the station equipment and building from lightning damage
C.
To lock the antenna system in one position
D.
To avoid radio frequency interference

B-003-020-001

Grounding antenna and rotator cables help direct an eventual lightning strike as directly to ground as possible.

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

Tags: none

B-003-020-002

You want to install a lightning surge protector on your transmission line, where should it be inserted?

A.
Behind the transceiver
Correct Answer
B.
Outside, as close to earth grounding as possible
C.
Close to the antenna
D.
Anywhere on the line

B-003-020-002

The lightning surge protector must be outside to prevent as much energy as possible from entering the premises. It must be close to ground so that a path with the least possible impedance (resistance + inductance) can divert the most energy into the ground. Peak voltage between the transmission line and ground is thus minimized. Rise time in a lightning bolt is measured in microseconds (i.e., high frequency); voltage is high and current is zero in the first instant an inductance is subjected to a pulse.

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

Tags: none

B-003-020-003

How can your station equipment best be protected from lightning damage?

A.
Use heavy insulation on the wiring
Correct Answer
B.
Disconnect all equipment from the power lines and antenna cables
C.
Disconnect the ground system from all radios
D.
Never turn off the equipment

B-003-020-003

If station equipment is totally disconnected from external circuits (power and antenna), damage to station equipment from lightning or voltage surges becomes impossible.

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

Tags: none

B-003-020-004

What equipment should be worn for working on an antenna tower?

Correct Answer
A.
Approved fall arrest equipment
B.
A reflective vest
C.
A pair of insulating gloves
D.
A positioning waist belt

B-003-020-004

In Canada, worker safety is a provincial responsibility. 'Fall arrest equipment' and a 'hard hat' are minimum requirements. A positioning waist belt will not prevent or stop a fall.

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

Tags: none

B-003-020-005

Why should you wear approved fall arrest equipment if you are working on an antenna tower?

A.
To bring any tools you might use up and down the tower safely
B.
To keep the tower from becoming unstable while you are working
Correct Answer
C.
To limit injuries if you fall
D.
To hold your tools so they don't fall and injure someone on the ground

B-003-020-005

'Fall prevention' is a serious matter. In Canada, worker safety is a provincial responsibility. 'Fall arrest equipment' and a 'hard hat' are minimum requirements. A positioning waist belt will not prevent or stop a fall.

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

Tags: none

B-003-020-006

For safety, how high should you place a horizontal wire antenna?

A.
Above high-voltage electrical lines
B.
As close to the ground as possible
C.
Just high enough so you can easily reach it for adjustments or repairs
Correct Answer
D.
High enough so that no one can touch any part of it from the ground

B-003-020-006

Even at modest power, touching a radiating antenna or open-wire line can lead to 'RF burns'. Voltage is not the only factor, radio frequency reaches deep into the skin, potentially causing nasty burns. Suspending an antenna above electric lines is a dangerous mistake: if the antenna dropped, lethal voltages would be carried back to the station.

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

Tags: none

B-003-020-007

Why should you wear a hard hat if you are on the ground helping someone work on an antenna tower?

A.
So you won't be hurt if the tower should accidentally fall
B.
To keep RF energy away from your head during antenna testing
Correct Answer
C.
To protect your head from something dropped from the tower
D.
So someone passing by will know that work is being done on the tower and will stay away

B-003-020-007

Think for a second about a screwdriver, a wrench or a heavy bolt falling on your head from a height of 14 metres (48 feet).

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

Tags: none

B-003-020-008

Why should your outside antennas be high enough so that no one can touch them while you are transmitting?

A.
Touching the antenna might cause television interference
B.
Touching the antenna might reflect the signal back to the transmitter and cause damage
Correct Answer
C.
Touching the antenna might cause RF burns
D.
Touching the antenna might radiate harmonics

B-003-020-008

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

Tags: none

B-003-020-009

Why should you make sure that no one can touch an open-wire transmission line while you are transmitting with it?

A.
Because contact might cause spurious emissions
B.
Because contact might break the transmission line
Correct Answer
C.
Because high-voltage radio energy might burn the person
D.
Because contact might cause a short circuit and damage the transmitter

B-003-020-009

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

Tags: none

B-003-020-010

What safety precautions should you take before beginning repairs on an antenna?

A.
Ensure all masts to be installed are sufficiently light
B.
Plan the operation in the shortest possible time to minimize fatigue
C.
Be sure the antenna structure is properly grounded
Correct Answer
D.
Be sure to turn off the transmitter and disconnect the transmission line

B-003-020-010

"Disconnecting the transmission line", that is an important precaution to ensure that no RF is ever sent to the antenna. This is especially important if there are several parties in the work crew: an operator could return to the station, turn-on a transmitter and put someone outside at risk.

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

Tags: none

B-003-020-011

What safety precaution is especially important for a ground-mounted antenna?

A.
Ensure the location is as dry as possible
Correct Answer
B.
Ensure people are kept at a safe distance
C.
All radials should be buried at least 15 cm deep
D.
Ensure the feed point is at eye level

B-003-020-011

A transmitting antenna involves two hazards. For one, even at modest power, touching a radiating antenna or open-wire line can lead to 'RF burns'. Voltage is not the only factor, radio frequency reaches deep into the skin, potentially causing nasty burns. The second hazard pertains to RF exposure: depending on the power used, a safe distance must be maintained.

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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