① 设计并制作一个主站，传送一路语音信号，其发射频率在30MHz~40MHz之间自行选择，发射峰值功率不大于20mW(50 假负载电阻上测定)，射频信号带宽及调制方式自定，主站传送信号的输入采用话筒和线路输入两种方式；

② 设计并制作一个从站，其接收频率与主站相对应，从站必须采用电池组供电，用耳机收听语音信号；

③ 当传送信号为300Hz~3400Hz的正弦波时，去掉收、发天线，用一个功率衰减20dB左右的衰减器连接主、从站天线端子，通过示波器观察从站耳机两端的接收波形，波形应无明显失真；

④ 主、从站室内通信距离不小于5米，题目中的通信距离是指主、从站两设备(含天线)间的最近距离；

⑤ 主、从站收发天线采用拉杆天线或导线，长度小于等于1米。

-① design and production of a main station, all the way to send voice signals, the firing frequency at 30MHz ~ 40MHz to choose between the launch peak power less than 20mW (50 　load resistance on the determination false), radio frequency signal modulation bandwidth and self- , the main station to send signals using the microphone input and line input in two ways　

② design and production of a slave, to receive the frequency corresponding to the main station, from the station battery power must be used with headphones to listen to voice signals　

③ When the transmission signal of 300Hz ~ 3400Hz sine wave, the removal of land, the antenna, with a power attenuation of about 20dB attenuator connecting to the main, from the antenna terminal station through the oscilloscope to observe from the headset on both ends of the receiving station waveform, waveform should no significant distortion　

④ owners, interior communication distance from the station is not less than 5 meters, the