The Kit

The kit is very clean and consists of a bag with the components, the PCB, the probe cable, the electrical diagram and the assembly instructions in English.

SMD components, which are difficult to solder and fragile, are already soldered on the printed circuit. The screen is a good quality 2.4-inch TFT LCD, delivered soldered on its printed circuit board as well.

Assembly

The assembly does not present any particular difficulties, everything is clear and perfectly explained. No component is missing.

Tests and adjustments

On power-up, the DSO 138 boots and displays the plot. The only adjustment consists of calibrating the measurement socket on the 1 kHz square source available on the card, by means of the two adjustable capacitors. Too much capacity, the response time is too low and the edges are rounded. Too few capacity, "spikes" appear, betraying oscillations.