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对于精密级仪表必须严格按操作说明使用,并控制其使用范围。...
Thursday, September 15, 2022
无线电台天线是一个(),可以将电磁波能量和高频电流能量进行可逆转...
Thursday, September 15, 2022
Thursday, September 15, 2022
微波SDH信道机为了能使用公务电话,必须启用的字节是()A、D1B、E2C、E1D、D2...
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Thursday, September 15, 2022
某一调频信号,其基带信号频率为fm,相位偏差为mf,当mf≤0....
Thursday, September 15, 2022
无线通信设备的设备制式、发射频率、发射功率及使用方法不得随意变动...
Thursday, September 15, 2022
HF电磁波主要传输方式是()传输。A、天波B、对流层C、地波D、视距...
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Monday, September 12, 2022
Monday, September 12, 2022
光直放系统主要设备分远端和近端,其中近端设备包括:()、()、()等。...
Monday, February 27, 2023
Monday, September 12, 2022
I型450MHz隧道中继器的增益为()dB,容许的误差为()dB。...
Saturday, October 29, 2022
Thursday, September 15, 2022
固定设备的无线通信设备均应采取防雷措施,接地电阻为不大于()Ω。...
Thursday, September 15, 2022
Thursday, September 15, 2022
Thursday, September 15, 2022
内燃机车、电力机车的机车台由机车直流控制电源系统供电,供电电压范...
Thursday, September 15, 2022