问题 问答题 简答题

何时需要对速调管进行机内重调?如何进行?

答案

参考答案:

在更换磁控管或速调管后或调显示器面板上“调谐”钮无效时,要进行本振的机内调谐。

步骤:雷达正常工作10min后,关掉AFC,把显示器面板上的调谐钮放中间位置,量程一般选在6nmile以上(或者说明书规定量程),将收发机内电表转换开关拨向收发机,然后:

1.用万用表测反射极电压,调粗调谐电位器,使电表指示-50v,然后撤去电表

2.将机内测试表转到调谐位置,调机械调谐螺丝,使调谐表指针偏转最大

3.将机内电表转晶体电流I或II,调粗调谐电位器,使针偏转最大

4.重复2—3,直到晶体电流最大时,屏幕上回波也最好(调谐表指针偏转最大)

5.“调本振衰减器”,使晶体电流在说明书规定值。

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阅读下面短文,按照句子结构的语法性和上下文连贯的要求,在空格处填入一个适当的词或使用括号中词语的正确形式填空,并将答案填写在答题卡标号为31—40的相应位置上。

It is difficult for parents of nearly every family to teach their children to be responsible for housework,    31   with one of the following suggestions, you really can get your children to help at home.

If you give your children the    32    (impress) that they can never do anything quite right, then they will regard    33   as unfit or unable persons.    34   children believe they can succeed, they will never become totally independent.

My daughter Carla’s fifth grade teacher got every child in her class   35   (feel) special. When students received less than a perfect test score, she would point out    36   they had mastered and declared firmly they could learn what they had missed.

You can see the same technique when you evaluate your    37   work at home. Don’t always scold and give lots of praise    38   . Talk about what he has done right, not about what he hasn’t done. If your child completes a difficult task, reward him    39    a Sunday trip or a ball game with Dad. Learning is a process of trying and failing and trying and   40   . If you teach your children not to fear a mistake of failure, they will learn faster and achieve success at last.