FCC T4B - 业余无线电实践与电台操作

#T4B01🔗

What is the effect of excessive microphone gain on SSB transmissions?

过度的麦克风增益对 SSB 传输有何影响？

Frequency instability

频率不稳定

Distorted transmitted audio

传输的音频失真

✓ 正确答案

Increased SWR

增加 SWR

Sideband inversion

边带反转

#T4B02🔗

Which of the following can be used to enter a transceiver’s operating frequency?

以下哪一项可用于输入收发器的工作频率？

The keypad or VFO knob

键盘或VFO旋钮_

✓ 正确答案

The CTCSS or DTMF encoder

CTCSS 或 DTMF 编码器

The Automatic Frequency Control

自动频率控制

All these choices are correct

这些选项都是正确的

#T4B03🔗

How is squelch adjusted so that a weak FM signal can be heard?

如何调整静噪以便可以听到微弱的 FM 信号？

Set the squelch threshold so that receiver output audio is on all the time

设置静噪阈值，使接收器输出音频始终开启

✓ 正确答案

Turn up the audio level until it overcomes the squelch threshold

调高音频电平，直到它超过静噪阈值

Turn on the anti-squelch function

开启防静噪功能

Enable squelch enhancement

启用静噪增强

#T4B04🔗

What does an FM signal sound like when received slightly off frequency?

当接收到稍微偏离频率的 FM 信号时，听起来是什么样的？

The audio increases in pitch

音频音高增加

The audio decrease in pitch

音频音调降低

There is no effect except for reduction in amplitude

除了幅度减小之外没有任何影响

The audio becomes distorted

音频变得失真

✓ 正确答案

#T4B05🔗

What does the scanning function of an FM transceiver do?

FM收发器的扫描功能有什么作用？

Checks incoming signal deviation

检查输入信号偏差

Prevents interference to nearby repeaters

防止干扰附近的中继器

Tunes through a range of frequencies to check for activity

调谐一系列频率以检查活动_

✓ 正确答案

Tunes through a range of frequencies to determine the antenna’s resonant frequency

调谐一系列频率以确定天线的谐振频率

#T4B06🔗

Which of the following controls could be used if the voice pitch of a single-sideband signal returning to your CQ call seems too high or low?

如果返回到 CQ 呼叫的单边带信号的音高看起来太高或太低，可以使用以下哪些控件？

The AGC or limiter

AGC 或限制器

The bandwidth selection

带宽选择

The tone squelch

音调压制

The RIT or Clarifier

RIT或澄清剂

✓ 正确答案

#T4B07🔗

What is a DMR “code plug”?

什么是 DMR“代码插头”？

An adapter cable used to connect a DMR radio to a computer for internet access

用于将 DMR 无线电连接到计算机以访问互联网的适配器电缆

Configuration data loaded onto your radio to access repeaters and talkgroups

配置数据加载到您的收音机上以访问中继器和通话组

✓ 正确答案

An upgrade to DMR programming software provided by the radio manufacturer to accommodate new radio models

无线电制造商提供的 DMR 编程软件升级，以适应新的无线电型号

A Coder-Decoder (CODEC) that converts analog voice data to DMR digital data and vice versa

编码器-解码器 (CODEC)，可将模拟语音数据转换为 DMR 数字数据，反之亦然

#T4B08🔗

What is the advantage of having a choice of receiver filter bandwidths in a multimode transceiver?

在多模收发器中选择接收器滤波器带宽有什么好处？

Permits monitoring several modes simultaneously by selecting a separate filter for each mode

通过为每种模式选择单独的滤波器，允许同时监控多种模式

Permits noise or interference reduction by selecting a bandwidth matching the mode

通过选择与模式匹配的带宽，允许降低噪声或干扰

✓ 正确答案

Increases the number of frequencies that can be stored in memory

增加可存储在内存中的频率数量

Increases the amount of offset between receive and transmit frequencies

增加接收频率和发射频率之间的偏移量

#T4B09🔗

How is a specific group of stations selected on a DMR digital voice transceiver?

如何在 DMR 数字语音收发器上选择特定的电台组？

By retrieving the frequencies from transceiver memory

通过从收发器内存中检索频率

By enabling the group’s CTCSS tone

通过启用群组的 CTCSS 音

By entering the group’s identification code

通过输入群组识别码

✓ 正确答案

By inserting a five-pin, pre-programmed code plug

通过插入五针预编程代码插头

#T4B10🔗

Which of the following receiver filter bandwidths provides the best signal-to-noise ratio for SSB reception?

以下哪个接收器滤波器带宽为 SSB 接收提供最佳信噪比？

500 Hz

500赫兹

1000 Hz

1000赫兹

2400 Hz

2400赫兹

✓ 正确答案

5000 Hz

5000 赫兹

#T4B11🔗

Which of the following must be programmed into a D-STAR digital transceiver before transmitting?

在发送之前，必须将以下哪项编程到 D-STAR 数字收发器中？

Your call sign

你的呼号

✓ 正确答案

Your output power

你的输出功率

The codec type being used

使用的编解码器类型

All these choices are correct

这些选项都是正确的

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FCC T4B - 业余无线电实践与电台操作

小节 T4B：业余无线电实践与电台操作