Canadian Basic Qualification pool, section B-003-004

Subelement B-003

B-003

Section B-003-004

B-003-004-001

In a basic CW transmitter, the output from the oscillator is:

A.
at the transmitted signal's power level
B.
at a submultiple of the operating frequency
C.
less stable than the transmitted signal
Correct Answer
D.
at the transmitted signal's frequency

B-003-004-001

Key word: BASIC. For the sake of simplicity, the oscillator runs directly at the operating frequency. More complex arrangements could include a multiplier or a mixer.

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-003-004-002

In a basic CW transmitter, what type of electricity directly powers each stage?

Correct Answer
A.
Direct current
B.
Radio frequency current
C.
Audio frequency current
D.
Alternating current

B-003-004-002

In fact, every stage using active components in any apparatus must be supplied with direct current (DC).

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-003-004-003

In a basic CW transmitter, why is the oscillator followed by a driver/buffer stage?

A.
To filter out noise from the oscillator
B.
To shape the oscillator waveform to prevent key clicks
C.
To filter out spurious emissions from the oscillator
Correct Answer
D.
To prevent load changes from shifting the oscillator's frequency

B-003-004-003

To achieve stability, oscillators are always low-level stages. Amplification must follow; that's the purpose of the driver/buffer.

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

Tags: none

B-003-004-004

In a basic three-stage CW transmitter, what does the key do?

A.
It switches the oscillator on and off
B.
It reduces key clicks
C.
It reduces key chirps
Correct Answer
D.
It controls the amplitude of the carrier

B-003-004-004

Telegraphy is equivalent to 'on-off keying' ( an 'interrupted carrier'). The telegraph key allows the operator to send bursts of RF energy to the antenna per the rhythm of his hand movement on the key.

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

Tags: none

B-003-004-005

In a basic CW transmitter, what does the power amplifier stage do?

Correct Answer
A.
It increases the transmitter's output power
B.
It reduces distortion in the transmitted signal
C.
It multiplies the oscillator frequency to the operating frequency
D.
It removes CW chirps from the transmitted signal

B-003-004-005

In all transmitters, the last stage before the antenna is a power amplifier which imparts the transmitted signal its actual power.

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

Tags: none

B-003-004-006

In a basic CW transmitter, what does the key do?

Correct Answer
A.
It switches the carrier on and off
B.
It switches the carrier between two frequencies
C.
It switches the transmitted tone on and off
D.
It makes and breaks the antenna connection

B-003-004-006

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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