DPScope - Build Your Own USB/PC-Based Oscilloscope

Step 22 Assembly Step 11: Trimmers, Resonator, Jumper

A few more small components are left: The two trimmers (VR1 and VR2, the blue blocks with the adjustment knob on the top), the ceramic resonator (X1), and the power selection jumper (PWR_SEL). Install them as shown below and put the red shorting block on the jumper in the position indicated in the zoomed-in picture (labeled “USB”); this jumper is used to select the optional external power supply & voltage regulator as the scope’s power source; per default these are not installed because the instrument gets its power through the USB connection.