Technician Subelement T8 Flashcards
Which of the following is a form of amplitude modulation?
A. Spread spectrum
B. Packet radio
C. Single sideband
D. Phase shift keying (PSK)
Single sideband
What type of modulation is most commonly used for VHF packet radio transmissions?
A. FM
B. SSB
C. AM
D. PSK
FM
Which type of voice mode is most often used for long-distance (weak signal) contacts on the VHF and UHF bands?
A. FM
B. DRM
C. SSB
D. PM
SSB
Which type of modulation is most commonly used for VHF and UHF voice repeaters?
A. AM
B. SSB
C. PSK
D. FM
FM
Which of the following types of emission has the narrowest bandwidth?
A. FM voice
B. SSB voice
C. CW
D. Slow-scan TV
CW
Which sideband is normally used for 10 meter HF, VHF, and UHF singlesideband communications?
A. Upper sideband
B. Lower sideband
C. Suppressed sideband
D. Inverted sideband
Upper sideband
What is an advantage of single sideband (SSB) over FM for voice transmissions?
A. SSB signals are easier to tune
B. SSB signals are less susceptible to interference
C. SSB signals have narrower bandwidth
D. All of these choices are correct
SSB signals have narrower bandwidth
What is the approximate bandwidth of a single sideband (SSB) voice signal?
A. 1 kHz
B. 3 kHz
C. 6 kHz
D. 15 kHz
3 kHz
What is the approximate bandwidth of a VHF repeater FM phone signal?
A. Less than 500 Hz
B. About 150 kHz
C. Between 10 and 15 kHz
D. Between 50 and 125 kHz
Between 10 and 15 kHz
What is the typical bandwidth of analog fast-scan TV transmissions on the 70 centimeter band?
A. More than 10 MHz
B. About 6 MHz
C. About 3 MHz
D. About 1 MHz
About 6 MHz
What is the approximate maximum bandwidth required to transmit a CW signal?
A. 2.4 kHz
B. 150 Hz
C. 1000 Hz
D. 15 kHz
150 Hz
What telemetry information is typically transmitted by satellite beacons?
A. The signal strength of received signals
B. Time of day accurate to plus or minus 1/10 second
C. Health and status of the satellite
D. All of these choices are correct
Health and status of the satellite
What is the impact of using too much effective radiated power on a satellite uplink?
A. Possibility of commanding the satellite to an improper mode
B. Blocking access by other users
C. Overloading the satellite batteries
D. Possibility of rebooting the satellite control computer
Blocking access by other users
Which of the following are provided by satellite tracking programs?
A. Maps showing the real-time position of the satellite track over the earth
B. The time, azimuth, and elevation of the start, maximum altitude, and end of a pass
C. The apparent frequency of the satellite transmission, including effects of Doppler shift
D. All of these choices are correct
All of these choices are correct
What mode of transmission is commonly used by amateur radio satellites?
A. SSB
B. FM
C. CW/data
D. All of these choices are correct
All of these choices are correct
What is a satellite beacon?
A. The primary transmit antenna on the satellite
B. An indicator light that shows where to point your antenna
C. A reflective surface on the satellite
D. A transmission from a satellite that contains status information
A transmission from a satellite that contains status information
Which of the following are inputs to a satellite tracking program?
A. The weight of the satellite
B. The Keplerian elements
C. The last observed time of zero Doppler shift
D. All of these choices are correct
The Keplerian elements
With regard to satellite communications, what is Doppler shift?
A. A change in the satellite orbit
B. A mode where the satellite receives signals on one band and transmits on another
C. An observed change in signal frequency caused by relative motion between the satellite and the earth station
D. A special digital communications mode for some satellites
An observed change in signal frequency caused by relative motion between the satellite and the earth station
What is meant by the statement that a satellite is operating in mode U/V?
A. The satellite uplink is in the 15 meter band and the downlink is in the 10 meter band
B. The satellite uplink is in the 70 centimeter band and the downlink is in the 2 meter band
C. The satellite operates using ultraviolet frequencies
D. The satellite frequencies are usually variable
The satellite uplink is in the 70 centimeter band and the downlink is in the 2 meter band