然后再测试数字信号的功率，MER，BER这几个关键指标，遇到需要分析故障原因时，可以借助频谱和星座图来做粗略判断，高端问题，还是要专业的频谱仪来做测试。
Digital field strength meter is different from analog field strength meter. When testing digital signal, the key index is not the level, but the power, so when you use digital field strength meter, you must first create the local channel meter. Then we test the digital signal power, Mer, Ber, these key indicators, when we need to analyze the cause of failure, we can use spectrum and constellation chart to make a rough judgment, high-end problems, or need a professional spectrograph to do the test.