FCC E2E - 电台操作实践

#E2E01🔗

Which of the following types of modulation is used for data emissions below 30 MHz?

以下哪种类型的调制用于低于 30 MHz 的数据发射？

DTMF tones modulating an FM signal

调制 FM 信号的 DTMF 音调

FSK

频移键控

✓ 正确答案

Pulse modulation

脉冲调制

Spread spectrum

扩频

#E2E02🔗

Which of the following synchronizes WSJT-X digital mode transmit/receive timing?

以下哪项可同步 WSJT-X 数字模式发送/接收时序？

Alignment of frequency shifts

频移对齐

Synchronization of computer clocks

计算机时钟同步

✓ 正确答案

Sync-field transmission

同步场传输

Sync-pulse timing

同步脉冲定时

#E2E03🔗

To what does the "4" in FT4 refer?

FT4中的“4”指的是什么？

Multiples of 4 bits of user information

4位用户信息的倍数

Four- tone continuous - phase frequency shift keying

四音连续相频移键控

✓ 正确答案

Four transmit/receive cycles per minute

每分钟四个传输/接收周期

All these choices are correct

所有这些选项都是正确的

#E2E04🔗

Which of the following is characteristic of the FST4 mode?

以下哪项是 FST4 模式的特征？

Four-tone Gaussian frequency shift keying

四音高斯频移键控

Variable transmit/receive periods

可变的发送/接收周期

Seven different tone spacings

七种不同的音间距

All these choices are correct

所有这些选项都是正确的

✓ 正确答案

#E2E05🔗

Which of these digital modes does not support keyboard-to-keyboard operation?

以下哪种数字模式不支持键盘到键盘操作？

WSPR

✓ 正确答案

RTTY

PSK31

相移键控31

MFSK16

#E2E06🔗

What is the length of an FT8 transmission cycle?

FT8 传输周期的长度是多少？

It varies with the amount of data

随数据量的变化而变化

8 seconds

8秒

15 seconds

15秒

✓ 正确答案

30 seconds

30秒

#E2E07🔗

How does Q65 differ from JT65?

Q65与JT65有何不同？

Keyboard-to keyboard operation is supported

支持键盘到键盘操作

Quadrature modulation is used

使用正交调制

Multiple receive cycles are averaged

多个接收周期被平均

✓ 正确答案

All these choices are correct

所有这些选项都是正确的

#E2E08🔗

Which of the following HF digital modes can be used to transfer binary files?

以下哪种 HF 数字模式可用于传输二进制文件？

PSK31

相移键控31

PACTOR

✓ 正确答案

RTTY

AMTOR

#E2E09🔗

Which of the following HF digital modes uses variable-length character coding?

以下哪种 HF 数字模式使用可变长度字符编码？

RTTY

PACTOR

MT63

PSK31

相移键控31

✓ 正确答案

#E2E10🔗

Which of these digital modes has the narrowest bandwidth?

以下哪种数字模式的带宽最窄？

MFSK16

170 Hz shift, 45-baud RTTY

170 Hz 移位，45 波特 RTTY

FT8

✓ 正确答案

PACTOR IV

帕托四世

#E2E11🔗

What is the difference between direct FSK and audio FSK?

直接 FSK 和音频 FSK 有什么区别？

Direct FSK modulates the transmitter VFO

直接 FSK 调制发射机 VFO

✓ 正确答案

Direct FSK occupies less bandwidth

直接FSK占用带宽更少

Direct FSK can transmit higher baud rates

直接FSK可以传输更高的波特率

All these choices are correct

所有这些选项都是正确的

#E2E12🔗

How do ALE stations establish contact?

ALE 站如何建立联系？

ALE constantly scans a list of frequencies, activating the radio when the designated call sign is received

ALE 不断扫描频率列表，在收到指定呼号时激活无线电

✓ 正确答案

ALE radios monitor an internet site for the frequency they are being paged on

ALE 无线电监控互联网站点的寻呼频率

ALE radios send a constant tone code to establish a frequency for future use

ALE 无线电发送恒定音调代码来建立频率以供将来使用

ALE radios activate when they hear their signal echoed by back scatter

当 ALE 无线电听到反向散射回声的信号时就会激活

#E2E13🔗

Which of these digital modes has the highest data throughput under clear communication conditions?

在清晰的通信条件下，以下哪种数字模式具有最高的数据吞吐量？

MFSK16

170 Hz shift, 45 baud RTTY

170 Hz 移位，45 波特 RTTY

FT8

PACTOR IV

帕托四世

✓ 正确答案

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FCC E2E - 电台操作实践

小节 E2E：电台操作实践