Take the other 4-pin header from the Low Pass Filter kit and carefully cut off 1 pin with a wire-
cutter, without damaging its plastic base. The headers are designed to break apart easily like this.
Keep the 1-pin section safely.
Install the 3-pin header section as shown. Insert the SHORT end of the pins into the PCB. This is
used as the input to the DVM (voltmeter) and RF power meter functions of the kit. You can later
jumper pins 1 to 3 to measure the supply voltage with an icon on the LCD during operation.
DVM貌似检测电压的 然后 跳哪儿去 没有看懂了