FCC E2B - 电台操作实践

#E2B01🔗

In digital television, what does a coding rate of 3/4 mean?

在数字电视中，3/4 的编码率意味着什么？

25 % of the data sent is forward error correction data

发送的数据中25%是前向纠错数据

✓ 正确答案

Data compression reduces data rate by 3/4

数据压缩将数据速率降低 3/4

1/4 of the time interval is used as a guard interval

时间间隔的1/4用作保护间隔

Three, four-bit words are used to transmit each pixel

使用三、四位字来传输每个像素

#E2B02🔗

How many horizontal lines make up a fast-scan (NTSC) television frame?

快速扫描 (NTSC) 电视帧由多少条水平线组成？

525

第525章

✓ 正确答案

1080

#E2B03🔗

How is an interlaced scanning pattern generated in a fast-scan (NTSC) television system?

快速扫描 (NTSC) 电视系统中的隔行扫描模式是如何生成的？

By scanning two fields simultaneously

同时扫描两个场

By scanning each field from bottom-to-top

通过从下到上扫描每个字段

By scanning lines from left-to-right in one field and right-to-left in the next

通过在一个字段中从左到右扫描行，在下一个字段中从右到左扫描行

By scanning odd - numbered lines in one field and even- numbered lines in the next

通过扫描一个场中的奇数行和下一场中的偶数行

✓ 正确答案

#E2B04🔗

How is color information sent in analog SSTV?

模拟 SSTV 中的颜色信息是如何发送的？

Color lines are sent sequentially

颜色线按顺序发送

✓ 正确答案

Color information is sent on a 2.8 kHz subcarrier

颜色信息在 2.8 kHz 副载波上发送

Color is sent in a color burst at the end of each line

颜色在每行末尾以色同步发送

Color is amplitude modulated on the frequency modulated intensity signal

颜色是在调频强度信号上进行幅度调制的

#E2B05🔗

Which of the following describes the use of vestigial sideband in analog fast-scan TV transmissions?

以下哪一项描述了残留边带在模拟快速扫描电视传输中的使用？

The vestigial sideband carries the audio information

残留边带携带音频信息

The vestigial sideband contains chroma information

残留边带包含色度信息

Vestigial sideband reduces the bandwidth while increasing the fidelity of low frequency video components

残留边带减少了带宽，同时提高了低频视频分量的保真度

✓ 正确答案

Vestigial sideband provides high frequency emphasis to sharpen the picture

残留边带提供高频强调以锐化图像

#E2B06🔗

What is vestigial sideband modulation?

什么是残留边带调制？

Amplitude modulation in which one complete sideband and a portion of the other are transmitted

幅度调制，其中一个完整的边带和另一个边带的一部分被传输

✓ 正确答案

A type of modulation in which one sideband is inverted

一种边带反转的调制类型

Narrow-band FM modulation achieved by filtering one sideband from the audio before frequency modulating the carrier

通过在对载波进行频率调制之前从音频中滤除一侧频带来实现窄带 FM 调制

Spread spectrum modulation achieved by applying FM modulation following single sideband amplitude modulation

通过在单边带幅度调制之后应用 FM 调制来实现扩频调制

#E2B07🔗

Which types of modulation are used for amateur television DVB-T signals?

业余电视 DVB-T 信号使用哪些类型的调制？

FM and FSK

调频和频移键控

QAM and QPSK

QAM 和 QPSK

✓ 正确答案

AM and OOK

AM 和 OOK

All these choices are correct

所有这些选项都是正确的

#E2B08🔗

What technique allows commercial analog TV receivers to be used for fast-scan TV operations on the 70-centimeter band?

什么技术允许使用商用模拟电视接收器在 70 厘米频段上进行快速扫描电视操作？

Transmitting on channels shared with cable TV

在与有线电视共享的频道上传输

✓ 正确答案

Using converted satellite TV dishes

使用改装的卫星电视天线

Transmitting on the abandoned TV channel 2

在废弃的电视频道 2 上传输

Using USB and demodulating the signal with a computer sound card

使用USB并用计算机声卡解调信号

#E2B09🔗

What kind of receiver can be used to receive and decode SSTV using the Digital Radio Mondiale (DRM) protocol?

什么样的接收器可用于使用 Digital Radio Mondiale (DRM) 协议接收和解码 SSTV？

CDMA

码分多址

AREDN

调幅

SSB

单边带

✓ 正确答案

#E2B10🔗

What aspect of an analog slow-scan television signal encodes the brightness of the picture?

模拟慢扫描电视信号的哪些方面对图像的亮度进行编码？

Tone frequency

音调频率

✓ 正确答案

Tone amplitude

音调幅度

Sync amplitude

同步幅度

Sync frequency

同步频率

#E2B11🔗

What is the function of the vertical interval signaling (VIS) code sent as part of an SSTV transmission?

作为 SSTV 传输的一部分发送的垂直间隔信令 (VIS) 代码的功能是什么？

To lock the color burst oscillator in color SSTV images

锁定彩色 SSTV 图像中的色同步振荡器

To identify the SSTV mode being used

识别正在使用的 SSTV 模式

✓ 正确答案

To provide vertical synchronization

提供垂直同步

To identify the call sign of the station transmitting

识别发射电台的呼号

#E2B12🔗

What signals SSTV receiving software to begin a new picture line?

什么信号表明 SSTV 接收软件开始新的图像线？

Specific tone frequencies

特定音调频率

✓ 正确答案

Elapsed time

经过时间

Specific tone amplitudes

特定音调幅度

A two-tone signal

双音信号

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FCC E2B - 电台操作实践

小节 E2B：电台操作实践