JYE Tech DSO 138 Oscilloscope DIY Kit User Manual

: June 12, 2024
: JYE Tech

JYE Tech DSO 138 Oscilloscope DIY Kit User Manual

Soldering Hints

Put leads through mounting holes from the side with
part outline. Ensue component evenly touch PCB.
Solder leads at the other side. Solder should fully
fill and cover soldering pads.
Avoid bridges between neighbering pads.
Cut unused leads flush with cutter.

Tools you need

Iron (20W) 1
Solder wire
Multimeter
Screw driver
Flush cutter
Tweezers

Before you start

Check part values & quantities against part list
Always meter resistor values before soldering
Understand all part polarities and orientations

Step 1

Assembly Main Board and LCD board (follow the order as nu mbered)

Display and Controls

Connections

Power Supply: Connect DC power supply to J9 or J10. The power supply voltage must be in the range of 8 – 12V.
Probe: Connect probe to J1.

Operations

Press on [SEL] button: Select parameter to be adjusted. The selected parameter will be highlighted.
Press on [+] or [-] button: Adjust the parameter selected by [SEL] button.
Press on [OK] button: Freeze waveform refresh (entering HOLD state). Press on it again will de-freeze.
Change [CPL] switch: Set couple to DC, AC, or GND. When GND is selected the scope input is isolated from input signal and connected to ground (0V input).
Change [SEN1] or [SEN2] switch: Adjust sensitivity. The product of [SEN1] and [SEN2] settings makes the actual sensitivity which is displayed at the lower- left corner of the panel. Press on [Reset] button: Perform a system reset and re-boots the oscillscope.

V Line Alignment

Sometimes you may find the 0V line (the trace corresponding to 0V input voltage) does not match with the VPOS indicator at the screen left border. This can easily be fixed by performing the “0V line alignment” function. First,
set the couple switch [CPL] to GND position. Then press on [SEL] button to make VPOS indicator highlighed and hold down [OK] button for about 2 seconds. You will set the trace aligned to VPOS indicator when you release
[OK] button. You may see some residue mismatch remains at the highest sensitivity settings. This is normal.

Probe Calibration

Because there is always some capacitance between scope input and ground probe needs to be calibrated to achieve better measurement results for high frequency signals. This can be done with the help of
the built-in test signal. To do this please follow the steps below

Connect the red clip to the test signal terminal and leave the
black clip un-connected (see photo at right).
Set [SEN1] switch to 0.1V and [SEN2] switch to X5.
Set [CPL] switch to AC or DC.
Adjust timebase to 0.2ms. You should see waveform similar to that shown in photos below. If traces are not stable adjust trigger level (the pink triangle on right screen border) so as you get a stable display.
Turn C4 (capacitor trimmer) with a small screw driver so that the waveform displays sharp rightangle (photo C).
Set [SEN1] switch to 1V and [SEN2] switch to X1while keep all other settings unchanged. Adjust C6 so that sharp rightangle waveform is displayed.

Turn On/Off Readouts

Press [SEL] so that timebase is highlighted. Hold down [OK] button for about 2 seconds. This will turn on/off measurement readouts.

Waveform Save/Recall

Press [SEL] & [+] simultaneously: Save currently displayed waveform to non- volatile memory
Press [SEL] & [-] simultaneously: Recall saved waveform

Triggers and Their Modes

Triggers are events that indicate signal voltage acrossing a set level (i.e. trigger level) along a specified direction
(i.e. trigger slope, rising or falling). Oscilloscope uses triggers as reference points in time for stable waveform display and measurements.

Auto Mode

In auto mode oscilloscope will perform display refresh no matter triggers happen or not. When triggers are detected waveform display will be displayed with reference to
trigger points. Otherwise, display waveform at ramdom reference points.

Normal Mode

In normal mode oscilloscope will only perform display refresh when there are triggers. If no triggers happen waveform display will stay unchanged.

Single Mode

Single mode is the same as normal mode except that oscilloscope will enter HOLD state after a trigger has been detected and waveform display has been updated.