FCC T8A - 调制模式与通信方式

#T8A01🔗

Which of the following is a form of amplitude modulation?

以下哪项是振幅调制的一种形式？

Spread spectrum

扩频

Packet radio

分组无线电

Single sideband

单边带 _

✓ 正确答案

Phase shift keying (PSK)

相移键控 (PSK)

#T8A02🔗

What type of modulation is commonly used for VHF packet radio transmissions?

VHF 分组无线电传输通常使用什么类型的调制？

FM or PM

✓ 正确答案

SSB

PSK

#T8A03🔗

Which type of voice mode is often used for long-distance (weak signal) contacts on the VHF and UHF bands?

VHF和UHF频段的长途（弱信号）联络常采用哪种语音方式？

DRM

SSB

✓ 正确答案

#T8A04🔗

Which type of modulation is commonly used for VHF and UHF voice repeaters?

VHF 和 UHF 语音中继器通常使用哪种类型的调制？

SSB

PSK

FM or PM

✓ 正确答案

#T8A05🔗

Which of the following signal types has the narrowest bandwidth?

以下哪种信号类型的带宽最窄？

FM voice

SSB voice

✓ 正确答案

Slow-scan TV

#T8A06🔗

Which sideband is normally used for 10-meter HF, VHF, and UHF single-sideband communications?

10 米 HF、VHF 和 UHF 单边带通信通常使用哪个边带？

Upper sideband

上边带

✓ 正确答案

Lower sideband

下边带

Suppressed sideband

抑制边带

Inverted sideband

倒边带

#T8A07🔗

What is one characteristic of single sideband (SSB) compared to FM?

与 FM 相比，单边带 (SSB) 的特点是什么？

SSB signals are easier to tune in correctly

SSB 信号更容易正确调谐

SSB signals are less susceptible to interference

SSB 信号不易受干扰

SSB signals have narrower bandwidth

SSB 信号的带宽较窄

✓ 正确答案

SSB signals are less susceptible to high SWR

SSB 信号不易受到高 SWR 的影响

#T8A08🔗

What is the approximate bandwidth of a typical single sideband (SSB) voice signal?

典型单边带 (SSB) 语音信号的带宽大约是多少？

1 kHz

1kHz

3 kHz

3kHz

✓ 正确答案

6 kHz

6kHz

15 kHz

15kHz

#T8A09🔗

What is the approximate bandwidth of an FM voice signal on VHF repeaters?

VHF 中继器上的 FM 语音信号的带宽大约是多少？

Less than 500 Hz

低于 500 赫兹

About 150 kHz

约 150 kHz

Between 10 and 15 kHz

10至15 kHz 之间

✓ 正确答案

Between 50 and 125 kHz

50 至 125 kHz 之间

#T8A10🔗

What is the approximate bandwidth of AM fast-scan TV transmissions?

AM 快速扫描电视传输的大约带宽是多少？

More than 10 MHz

超过 10 MHz

About 6 MHz

约6兆赫

✓ 正确答案

About 3 MHz

约 3 兆赫

About 1 MHz

约 1 兆赫

#T8A11🔗

What is the approximate bandwidth required to transmit a CW signal?

传输 CW 信号所需的大约带宽是多少？

2.4 kHz

2.4 赫兹

150 Hz

150赫兹

✓ 正确答案

1000 Hz

1000赫兹

15 kHz

15 赫兹

#T8A12🔗

Which of the following is a disadvantage of FM compared with single sideband?

与单边带相比，下列哪项是 FM 的缺点？

Voice quality is poorer

语音质量较差

Only one signal can be received at a time

一次只能接收一个信号

✓ 正确答案

FM signals are harder to tune

调频信号更难调谐

FM signals are more susceptible to high SWR

FM 信号更容易受到高 SWR 的影响

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FCC T8A - 调制模式与通信方式

小节 T8A：调制模式与通信方式