FCC T9B - 天线与馈线系统

#T9B01🔗

Which of the following connectors should be carefully taped for weather protection when used outdoors?

在户外使用时，应仔细粘贴以下哪些连接器以免受天气影响？

PL259

BNC

Type N

N型

All these choices are correct

这些选项都是正确的

✓ 正确答案

#T9B02🔗

What is the most common impedance of coaxial cables used in amateur radio?

业余无线电中使用的同轴电缆最常见的阻抗是多少？

8 ohms

8欧姆

50 ohms

50欧姆

✓ 正确答案

600 ohms

600 欧姆

12 ohms

12 欧姆

#T9B03🔗

Why is coaxial cable the most common feed line for amateur radio antenna systems?

为什么同轴电缆是业余无线电天线系统最常见的馈线？

It is easy to use and requires few special installation considerations

它易于使用，几乎不需要特殊的安装注意事项

✓ 正确答案

It has less loss than any other type of feed line

与任何其他类型的馈线相比，它的损耗更少

It can handle more power than any other type of feed line

它可以处理比任何其他类型的馈线更多的功率

It is less expensive than any other type of feed line

它比任何其他类型的馈线都便宜

#T9B04🔗

What is the major function of an antenna tuner (antenna coupler)?

天线调谐器（天线耦合器）的主要功能是什么？

It matches the antenna system impedance to the transceiver 's output impedance

它将天线系统阻抗与收发器的输出阻抗相匹配

✓ 正确答案

It helps a receiver automatically tune in weak stations

它可以帮助接收器自动调谐弱电台

It allows an antenna to be used on both transmit and receive

它允许天线用于发射和接收

It automatically selects the proper antenna for the frequency band being used

它会自动为正在使用的频段选择合适的天线

#T9B05🔗

What happens as the frequency of a signal in coaxial cable is increased?

当同轴电缆中的信号频率增加时会发生什么？

The characteristic impedance decreases

特性阻抗降低

The loss decreases

损失减少

The characteristic impedance increases

特性阻抗增加

The loss increases

损失增加

✓ 正确答案

#T9B06🔗

Which of the following connector types is most suitable as an RF connector for frequencies above 400 MHz?

以下哪种连接器类型最适合用作频率高于 400 MHz 的射频连接器？

PL-259

Type N

N 型

✓ 正确答案

RS-213

DB-25

#T9B07🔗

Which of the following is true of PL-259 type coax connectors?

关于 PL-259 型同轴连接器，下列哪项是正确的？

They are preferred for microwave operation

它们是微波操作的首选

They are watertight

它们是防水的

They are commonly used at HF and VHF frequencies

它们通常用于HF和VHF 频率

✓ 正确答案

They are a bayonet-type connector

它们是卡口式连接器

#T9B08🔗

Which of the following is a source of loss in coaxial feed line?

以下哪项是同轴馈线的损耗来源？

Water intrusion into coaxial connectors

同轴连接器进水

High SWR

高驻波比

Multiple connectors in the line

线路中的多个连接器

All these choices are correct

这些选项都是正确的

✓ 正确答案

#T9B09🔗

What can cause erratic changes in SWR?

什么会导致 SWR 的不稳定变化？

Local thunderstorm

局地雷雨

Loose connection in the antenna or feed line

天线或馈线连接松动_ _

✓ 正确答案

Over-modulation

过度调制

Overload from a strong local station

来自强大的本地站的过载

#T9B10🔗

What is the electrical difference between RG-58 and RG-213 coaxial cable?

RG-58和RG-213同轴电缆的电气区别是什么？

There is no significant difference between the two types

两种类型之间没有显着差异

RG-58 cable has two shields

RG-58 电缆有两个屏蔽层

RG- 213 cable has less loss at a given frequency

RG- 213电缆在给定频率下损耗较小

✓ 正确答案

RG-58 cable can handle higher power levels

RG-58 电缆可以处理更高的功率水平

#T9B11🔗

Which of the following types of feed line has the lowest loss?

以下哪种类型的馈线损耗最低？

50-ohm flexible coax

50 欧姆柔性同轴电缆

Multi-conductor unbalanced cable

多芯不平衡电缆

Air - insulated hardline

空气绝缘硬线

✓ 正确答案

75-ohm flexible coax

75 欧姆柔性同轴电缆

#T9B12🔗

What is standing wave ratio (SWR)?

什么是驻波比（SWR）？

A measure of how well a load is matched to a transmission line

衡量负载与传输线匹配程度的指标

✓ 正确答案

The ratio of amplifier power output to input

功放功率输出输入比

The transmitter efficiency ratio

发射机效率比

An indication of the quality of your station’s ground connection

表明您电台接地连接的质量

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FCC T9B - 天线与馈线系统

小节 T9B：天线与馈线系统