2007 General Class Questions Pool

This pool is valid for Element 3 exams given on or after July 1, 2007]

SUBELEMENT G8 - SIGNALS AND EMISSIONS
[2 Exam Questions -- 2 Groups]

G8A - Carriers and modulation: AM; FM; single and double sideband ; modulation envelope; deviation; overmodulation

G8A01
What is the name of the process that changes the envelope of an RF wave to convey information?
A. Phase modulation
B. Frequency modulation
C. Spread Spectrum modulation
D. Amplitude modulation

G8A02
What is the name of the process that changes the phase angle of an RF wave to convey information?
A. Phase convolution
B. Phase modulation

C. Angle convolution
D. Radian Inversion

G8A03
What is the name of the process which changes the frequency of an RF wave to convey information?
A. Frequency convolution
B. Frequency transformation
C. Frequency conversion
D. Frequency modulation

G8A04
What emission is produced by a reactance modulator connected to an RF power amplifier?
A. Multiplex modulation
B. Phase modulation

C. Amplitude modulation
D. Pulse modulation

G8A05
What type of transmission varies the instantaneous power level of the RF signal to convey information?
A. Frequency shift keying
B. Pulse modulation
C. Frequency modulation
D. Amplitude modulation

G8A06
What is one advantage of carrier suppression in a single-sideband phone transmission?
A. Audio fidelity is improved
B. Greater modulation percentage is obtainable with lower distortion
C. More transmitter power can be put into the remaining sideband

D. Simpler receiving equipment can be used

G8A07
Which of the following phone emissions uses the narrowest frequency bandwidth?
A. Single sideband

B. Double sideband
C. Phase modulation
D. Frequency modulation

G8A08
What happens to the signal of an over-modulated single-sideband phone transmitter?
A. It becomes louder with no other effects
B. It occupies less bandwidth with poor high frequency response
C. It has higher fidelity and improved signal to noise ratio
D. It becomes distorted and occupies more bandwidth

G8A09
What control is typically adjusted for proper ALC setting on an amateur single sideband transceiver?
A. The RF Clipping Level
B. Audio or microphone gain

C. Antenna inductance or capacitance
D. Attenuator Level

G8A10
What is meant by flat-topping of a single-sideband phone transmission?
A. Signal distortion caused by insufficient collector current
B. The transmitter's automatic level control is properly adjusted
C. Signal distortion caused by excessive drive

D. The transmitter's carrier is properly suppressed

G8A11
What happens to the RF carrier signal when a modulating audio signal is applied to an FM transmitter?
A. The carrier frequency changes proportionally to the instantaneous amplitude of the modulating signal

B. The carrier frequency changes proportionally to the amplitude and frequency of the modulating signal
C. The carrier amplitude changes proportionally to the instantaneous frequency of the modulating signal
D. The carrier phase changes proportionally to the instantaneous amplitude of the modulating signal

G8A12
What signal(s) would be found at the output of a p roperly adjusted balanced modulator?
A. Both upper and lower sidebands

B. Either upper or lower sideband, but not both
C. Both upper and lower sidebands and the carrier
D. The modulating signal and the unmodulated carrier

G8B - Frequency mixing; multiplication; HF data communications; bandwidths of various modes

G8B01
What receiver stage combines a 14.250 MHz input signal with a 13.795 MHz oscillator signal to produce a 455 kHz intermediate frequency (IF) signal?
A. Mixer

B. BFO
C. VFO
D. Multiplier

G8B02
If a receiver mixes a 13.800 MHz VFO with a 14.255 MHz received signal to produce a 455 kHz intermediate frequency (IF) signal, what type of interference will a 13.345 MHz signal produce in the receiver?
A. Local oscillator
B. Image response

C. Mixer interference
D. Intermediate interference

G8B03
What stage in a transmitter would change a 5.3 MHz input signal to 14.3 MHz?
A. A mixer

B. A beat frequency oscillator
C. A frequency multiplier
D. A linear translator

G8B04
What is the name of the stage in a VHF FM transmitter that selects a harmonic of an HF signal to reach the desired operating frequency?
A. Mixer
B. Reactance modulator
C. Pre-emphasis network
D. Multiplier

G8B05
Why isn't frequency modulated (FM) phone used below 29.5 MHz?
A. The transmitter efficiency for this mode is low
B. Harmonics could not be attenuated to practical levels
C. The bandwidth would exceed FCC limits

D. The frequency stability would not be adequate

G8B06
What is the total bandwidth of an FM-phone transmission having a 5 kHz deviation and a 3 kHz modulating frequency?
A. 3 kHz
B. 5 kHz
C. 8 kHz
D. 16 kHz

G8B07
What is the frequency deviation for a 12.21-MHz reactance-modulated oscillator in a 5-kHz deviation, 146.52-MHz FM-phone transmitter?
A. 101.75 Hz
B. 416.7 Hz

C. 5 kHz
D. 60 kHz

G8B08
How is frequency shift related to keying speed in an FSK signal?
A. The frequency shift in hertz must be at least four times the keying speed in WPM
B. The frequency shift must not exceed 15 Hz per WPM of keying speed
C. Greater keying speeds require greater frequency shifts

D. Greater keying speeds require smaller frequency shifts

G8B09
What do RTTY, Morse code, PSK31 and packet communications have in common?
A. They require the same bandwidth
B. They are digital modes

C. They use on/off keying
D. They use phase shift modulation

G8B10
When transmitting a data mode signal, why is it important to know the duty cycle of the mode you are using?
A. To aid in tuning your transmitter
B. To prevent damage to your transmitter's final output stage

C. To allow time for the other station to break in during a transmission
D. All of these choices are correct

G8B11
What part of the 20 meter band is most commonly used for PSK31 operation?
A. At the bottom of the slow-scan TV segment, near 14.230 MHz
B. At the top of the SSB phone segment, near 14.325 MHz
C. In the middle of the CW segment, near 14.100 MHz
D. Below the RTTY segment, near 14.070 MHz

G8B12
What is another term for the mixing of two RF signals?
A. Heterodyning

B. Synthesizing
C. Cancellation
D. Multiplying

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