2.3 KiB
T8A – Basic characteristics of FM and SSB; Bandwidth of various modulation modes: CW, SSB, FM, fast-scan TV; Choice of emission type: selection of USB vs LSB, use of SSB for weak signal work, use of FM for VHF packet and repeaters
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T8A01 (C) Which of the following is a form of amplitude modulation? #card
- A. Spread spectrum
- B. Packet radio
- C. Single sideband
- D. Phase shift keying (PSK)
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T8A02 (A) What type of modulation is commonly used for VHF packet radio transmissions? #card
- A. FM or PM
- B. SSB
- C. AM
- D. PSK
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T8A03 (C) Which type of voice mode is often used for long-distance (weak signal) contacts on the VHF and UHF bands? #card
- A. FM
- B. DRM
- C. SSB
- D. PM
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T8A04 (D) Which type of modulation is commonly used for VHF and UHF voice repeaters? #card
- A. AM
- B. SSB
- C. PSK
- D. FM or PM
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T8A05 (C) Which of the following types of signal has the narrowest bandwidth? #card
- A. FM voice
- B. SSB voice
- C. CW
- D. Slow-scan TV
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T8A06 (A) Which sideband is normally used for 10 meter HF, VHF, and UHF single-sideband communications? #card
- A. Upper sideband
- B. Lower sideband
- C. Suppressed sideband
- D. Inverted sideband
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T8A07 (C) What is a characteristic of single sideband (SSB) compared to FM? #card
- A. SSB signals are easier to tune in correctly
- B. SSB signals are less susceptible to interference
- C. SSB signals have narrower bandwidth
- D. All these choices are correct
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T8A08 (B) What is the approximate bandwidth of a typical single sideband (SSB) voice signal? #card
- A. 1 kHz
- B. 3 kHz
- C. 6 kHz
- D. 15 kHz
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T8A09 (C) What is the approximate bandwidth of a VHF repeater FM voice signal? #card
- A. Less than 500 Hz
- B. About 150 kHz
- C. Between 10 and 15 kHz
- D. Between 50 and 125 kHz
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T8A10 (B) What is the approximate bandwidth of AM fast-scan TV transmissions? #card
- A. More than 10 MHz
- B. About 6 MHz
- C. About 3 MHz
- D. About 1 MHz
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T8A11 (B) What is the approximate bandwidth required to transmit a CW signal? #card
- A. 2.4 kHz
- B. 150 Hz
- C. 1000 Hz
- D. 15 kHz
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T8A12 (B) Which of the following is a disadvantage of FM compared with single sideband? #card
- A. Voice quality is poorer
- B. Only one signal can be received at a time
- C. FM signals are harder to tune
- D. All these choices are correct