Canadian Basic Qualification pool, section B-003-014

Subelement B-003

B-003

Section B-003-014

B-003-014-001

What do many amateur radio operators use to help form good Morse code characters?

A.
Straight key
Correct Answer
B.
Electronic keyer
C.
DTMF keypad
D.
Touchpad

B-003-014-001

A 'keyer' is an electronic circuit to which connects a 'paddle'. The 'keyer' issues dots and dashes in response to contact closures on the 'paddle' by the operator. Dots and dashes are uniformly timed and spaced. The 'paddle' relies on a side to side motion of the hand; it does not lead to fatigue, as the traditional hand key does after a while.

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

Tags: none

B-003-014-002

How does an electronic keyer help form good Morse code characters?

Correct Answer
A.
By regulating the lengths of the dits and dahs
B.
By eliminating key clicks
C.
By improving the tone of the CW signal
D.
By ensuring that the dots and dashes have the same amplitude

B-003-014-002

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

Tags: none

B-003-014-003

What do you need to adjust before using a microphone for the first time with a transceiver?

A.
Automatic gain control level
B.
Deviation control
C.
Noise blanker threshold
Correct Answer
D.
Microphone gain level

B-003-014-003

Remember your transmitter block diagrams: the microphone connects to the speech amplifier, the first stage in a voice transmitter.

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

Tags: none

B-003-014-004

What noise management system analyzes noise and signal characteristics to partially remove noise?

A.
Noise canceller (phasing)
Correct Answer
B.
DSP noise reduction
C.
Noise blanker
D.
Noise limiter

B-003-014-004

Key word: ANALYZES. Specialized programming allows a digital signal processor (DSP) to perform that analysis.

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

Tags: none

B-003-014-005

What circuit causes a transmitter to automatically transmit when an operator speaks into its microphone?

Correct Answer
A.
VOX
B.
VCO
C.
VFO
D.
VXO

B-003-014-005

VOX = "Voice Operated Transmit". VFO = "Variable Frequency Oscillator". [ the other two are beyond the scope of a Basic certificate. ]

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

Tags: none

B-003-014-006

What is the reason for using a properly adjusted speech processor with a single-sideband voice transmitter?

Correct Answer
A.
It improves the intelligibility of your signal
B.
It reduces unwanted noise pickup from the microphone
C.
It reduces average transmitter power requirements
D.
It improves voice frequency fidelity

B-003-014-006

The 'speech processor' makes for more average power being packed in the transmitted sideband. 'Speech processing' is raising the average amplitude of the audio input from the microphone closer to an acceptable peak value: i.e., make every passage of the spoken words equally loud. The AVERAGE can be increased but not the PEAK. Too much speech processing leads to distortion and possibly overdriving the linear power amplifier, possibly resulting in excessive occupied bandwidth.

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

Tags: none

B-003-014-007

If a single-sideband voice transmitter is 100% modulated, how will using a speech processor affect the transmitter's output?

A.
Decrease the average power
B.
Decrease the peak envelope power
C.
Increase the peak envelope power
Correct Answer
D.
Increase the average power

B-003-014-007

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

Tags: none

B-003-014-008

In a receiver, what noise management circuit recognizes high-amplitude short-duration pulses and removes them?

A.
Noise limiter
B.
Automatic level control
Correct Answer
C.
Noise blanker
D.
Narrowband filter

B-003-014-008

Key words: SHORT-DURATION. A noise blanker deals with a very specific type of radio noise: the high-amplitude short-duration pulses.

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

Tags: none

B-003-014-009

What type of interference is a noise blanker circuit most effective in eliminating?

A.
Distortion from overdeviated signals
B.
Continuous wideband background noise
Correct Answer
C.
Short-duration impulse-type noise
D.
Interfering signals on the same frequency

B-003-014-009

Key words: SHORT-DURATION. A noise blanker deals with a very specific type of radio noise: the high-amplitude short-duration pulses.

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

Tags: none

B-003-014-010

What is the function of transmit/receive switching in a transceiver?

A.
To prevent RF currents entering the transmitter circuits
B.
To change antennas for operation on other frequencies
C.
To allow more than one transmitter to be used
Correct Answer
D.
To enable one antenna to be used for both transmitting and receiving

B-003-014-010

Switching from receive to transmit supposes FOUR actions: disconnect the antenna from the receiver, connect the antenna to the transmitter, silence the receiver and activate the power amplifier in the transmitter. Typically, a 'relay' (a multiple contact electrically driven switch) performs the antenna changeover and the enabling/disabling of the transceiver sections.

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

Tags: none

B-003-014-011

What type of microphone has internal components similar to a loudspeaker?

A.
Crystal
B.
Electret
C.
Condenser
Correct Answer
D.
Dynamic

B-003-014-011

A 'Dynamic Microphone' is built around a membrane, a voice coil and a magnet: sound waves cause the membrane to vibrate, the voice coil, attached to the membrane, moves in and out of a magnetic field, thus producing a tiny electrical signal corresponding to the voice. A loudspeaker employs the reverse principle: an audio signal applied to the voice coil moves the membrane to reproduce sound waves.

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

Tags: none

Log in

- or -