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彩色电视机比黑白电视机对天线的要求高得多,这是因为我国电视台发射的都是彩色全电视信号。彩色电视机收到全电视信号后,要把4.43兆赫色同步信号分析出来,通过解码电路输出色度信号,使荧光屏显示彩色图像。色同步信号比全电视信号弱得多。所以,当天线收到的信号较弱时,色同步信号就容易丢失,使解码电路因失去色同步信号而无法正常工作,这样就收不到彩色图像,使清晰度降低。经实测,在城镇里同一地点接收同一发射台的电视播发,黑白电视机天线收到的电视波场强为3000UV/m 时,清晰度即可满足要求,而彩色
Color TV sets are much more demanding than antennas for black and white TVs because of the full color TV signal emitted by our television stations. After the color TV receives the full TV signal, it is necessary to analyze the 4.43 MHz color burst signal and output the chrominance signal through the decoding circuit to make the color screen display a color image. The color burst is much weaker than the full TV signal. Therefore, when the signal received by the antenna is weak, the burst signal is easily lost, which causes the decoding circuit to fail to work normally due to the loss of the burst signal. As a result, no color image is received and the resolution is reduced. The measured transmission in the same place in the town receiving the same transmitter television broadcast, black and white TV antenna TV antenna field received 3000UV / m, the sharpness to meet the requirements, and color