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选购彩色电视机时,在无测试仪器的情况下,可从以下几方面来鉴别质量:一、光栅。接通电源,打开开关,光栅应能充满整个屏幕,并无明显的枕形或者桶形失真。同时,注意机内有无打火、焦糊及各种干扰现象。二、灵敏度。直接表现为图像的对比度和音量的调节范围。如不用室外天线就可接收到补底较干净、图像较清晰的电视信号,且对比度和音量调节余量较大,则表明灵敏度较高;如补底有较多的色噪点,则说明灵敏度较低。三、清晰度。要求比一般黑白电视机清晰度高。选择时最好在有测试卡信号时进行,其水平分辨率应在300线以上,尤其注意辨别是不是由于镶边等引起的虚假现象,在无测试卡
When buying color TV sets, in the absence of test equipment, the quality can be identified from the following aspects: First, the grating. Turn on the power, turn on the switch, the grating should fill the entire screen with no noticeable pincushion or barrel distortion. At the same time, pay attention to whether the machine sparks, scorching and all kinds of interference. Second, the sensitivity. Directly for the image contrast and volume adjustment range. If you do not have outdoor antenna can receive more clean, clear image of the television signal, and the contrast and volume adjustment margin larger, indicating higher sensitivity; such as the bottom of the more colored noise, then the sensitivity of the more low. Third, clarity. Requirements than the average black and white TV clarity. The best choice when there is a test card signal, the horizontal resolution should be above 300 lines, with particular attention to identify whether the false phenomenon caused by the flanger, in the absence of test card