Canadian Basic Qualification pool, section B-003-001

Subelement B-003

B-003

Section B-003-001

B-003-001-001

To be most effective, where should a low-pass filter be connected in an HF station without an external power amplifier?

A.
As close as possible to the antenna switch output
Correct Answer
B.
As close as possible to the transceiver output
C.
Between the antenna tuner and the antenna switch
D.
Between the SWR meter and the antenna tuner

B-003-001-001

A 'low-pass' filter serves to reduce 'harmonics' which can be generated in overdriven, improperly adjusted or malfunctioning AMPLIFIER stages, either the actual power amplifier in a transmitter or an external linear power amplifier. Consequently, it should be inserted as close as possible to the transceiver or amplifier if one is used. The HF station block diagram begins with: transceiver, linear amplifier (optional), low-pass filter, SWR meter, antenna switch...

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

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B-003-001-002

In an HF station that includes an external RF power amplifier, where should a low-pass filter be located?

A.
As close as possible to the transceiver output
Correct Answer
B.
As close as possible to the external amplifier output
C.
Between the SWR meter and the antenna tuner
D.
Between the antenna tuner and the antenna switch

B-003-001-002

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

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B-003-001-003

Why do modern HF transmitters have a built-in low-pass filter in their RF output circuits?

A.
To reduce adjacent channel interference
B.
To reduce RF energy below a cut-off point
Correct Answer
C.
To reduce harmonic emissions
D.
To reduce fundamental emission

B-003-001-003

Manufacturers must meet spectral purity standards, notably for spurious emissions, such as harmonics. In a multiband transmitter, a different internal low-pass filter is activated as the frequency increases.

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

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B-003-001-004

Which component in an HF station is used to determine if the antenna system impedance is matched to the transmitter?

Correct Answer
A.
SWR meter
B.
Frequency meter
C.
S-meter
D.
Multimeter

B-003-001-004

The 'SWR meter' permits measuring the relative impedance match between the antenna system and the transceiver (SWR = Standing Wave Ratio). The HF station block diagram begins with: transceiver, linear amplifier (optional), low-pass filter, SWR meter, antenna switch...

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

Tags: none

B-003-001-005

What is the purpose of the antenna switch in an HF station?

A.
To adjust the impedance of the antenna system
B.
To adjust the antenna operating frequency
C.
To select the orientation of the antenna
Correct Answer
D.
To select the desired antenna or dummy load

B-003-001-005

The 'antenna switch' provides a convenient way to select a direct connection to an antenna, a connection through the 'antenna tuner' to other antennas or to the 'dummy load'. The HF station block diagram begins with: transceiver, linear amplifier (optional), low-pass filter, SWR meter, antenna switch...

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

Tags: none

B-003-001-006

In an HF station, what device might allow the use of an antenna on a band it was not designed for?

A.
An SWR meter
B.
A low-pass filter
C.
A high-pass filter
Correct Answer
D.
An antenna tuner

B-003-001-006

The 'antenna tuner' in an adjustable impedance matching network: it can adapt the impedance of the antenna system (which changes with antenna dimensions and operating frequency) to the design impedance of the transceiver. The 'antenna tuner' permits using an antenna on a frequency or band other than the one for which it was designed.

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

Tags: none

B-003-001-007

In an HF station, which component is designed to dissipate RF energy and prevent radiation?

Correct Answer
A.
Dummy load
B.
Lightning surge protector
C.
Low-pass filter
D.
Heat sink

B-003-001-007

The 'dummy load' (a resistor with a high power rating) dissipates RF energy as heat without radiating the RF on the air. Permits tests or adjustments without causing interference to other stations.

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

Tags: none

B-003-001-008

In an HF station, right after which component is the SWR meter inserted?

A.
The antenna tuner
Correct Answer
B.
The low-pass filter
C.
The last stage of RF amplification
D.
The antenna switch

B-003-001-008

Placing the SWR meter in between the low-pass filter and the antenna tuner allows the operator to verify that an adequate impedance is presented to the filter and evaluate the impedance match of the antenna system more accurately. The HF station block diagram begins with: transceiver, linear amplifier (optional), low-pass filter, SWR meter, antenna switch...

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

Tags: none

B-003-001-009

When using an HF transmitter with a solid-state final amplifier, which station component may need to be adjusted when changing frequency?

A.
SWR meter
B.
Low-pass filter
C.
Dummy load
Correct Answer
D.
Antenna tuner

B-003-001-009

Contrary to vacuum tube power amplifiers of yesteryear, solid-state power amplifiers do not include an adjustable impedance matching network. Such amplifiers are designed to work properly into a relatively small range of impedances. An antenna tuner allows using an antenna outside its normal bandwidth, or, within reason, on another band. Such flexibility supposes more frequent adjustments as operating frequency changes.

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

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