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With this kit, JYE Tech is launching the successor to the DSO138. A DIY oscilloscope costing less than twenty euros with a specified bandwidth of 500 kHz. We built and tested one. |
Introducing the DSO183 from JYE Tech
The end result
The end result of a few hours' tinkering is shown in the photo below. A 115 mm by 77 mm circuit board that contains both pre-mounted SMD components and through-hole components to be soldered by the user. Surrounding the PCB is an extremely simple 'housing', consisting of two sheets of transparent plastic that you attach to either side of the PCB using eight bolts. On the left are three slide switches, which allow you to adjust the sensitivity of the device. On the right are four push-buttons, enabling you to operate the oscilloscope in a very intuitive manner. On the top of the circuit board, the BNC connector for the signal to be measured is mounted on the left and a USB-3 connector for the 5 Vdc supply voltage on the right. Prominently featured on the circuit board is the TFT colour LCD display with a resolution of 320 by 240 pixels. On the underside of the board are five metal pins, each providing a sine, triangle or square-wave voltage with a frequency of 1 or 2 kHz.
The pin furthest to the right also provides a 1 kHz square wave, but one with steep rising and falling edges for calibrating a measuring probe.
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| The end result of this kit. (© JYE Tech) |
Manufacturer, suppliers and price
The kit is marketed by the well-known Chinese firm JYE Tech. This company specialises in designing (very) inexpensive kits for electronic measuring equipment aimed at students and hobbyists. The DSO183 is one such low-cost kit. You can buy the kit for around twenty euros from all the well-known Chinese mail-order companies such as AliExpress and Banggood. Most suppliers offer the kit in two versions: with and without the case. However, the price difference is only three euros, so it doesn't make much difference.
Delivery of the kit
Like most Chinese kits, the DSO183 is delivered in a rather crammed plastic bag, which in turn is contained within a larger postal envelope. The parcel fits easily through the letterbox, so you don't need to stay at home to receive it.
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| Delivery of the kit. (© 2026 Jos Verstraten) |
The components supplied
In the photo below, we have neatly laid out all the parts contained in the plastic bag. So no 1/10 probe is included, only a BNC cable with crocodile clips. Understandable at this price!
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| The components supplied. (© 2026 Jos Verstraten) |
The assembly instructions
No paper documentation is supplied with the kit. However, the manufacturer's website features a number of PDF files, including a Chinese document that provides a fairly detailed explanation of the DSO183's electronics. Well done! We have translated this file for you using Google Translate and have conveniently combined all the documentation into a single large PDF file that you can download from our Google Drive account:
The circuit board
The figure below shows both sides of the circuit board. As you can see, not only is the display already mounted, but so are the four chips, three transistors and a large number of SMD resistors and capacitors. You only need to solder the left-hand side of the board.
On the reverse side of the PCB there are three solder bridges: JP1, JP2 and JP4. JP4 is used to set the language of the user interface. An open solder bridge indicates English, a closed one indicates Chinese. If you close JP1 and JP2, you can perform a firmware upgrade via the USB interface.
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| The two sides of the PCB. (© 2026 Jos Verstraten) |
What immediately stands out on the back of the PCB is that the solder pads around the holes are extremely small. You will therefore need to use a soldering iron with a very fine tip and ensure the solder flows properly into the through-holes. In the photo below, we have compared the diameter of the pads with the diameter of a resistor lead.
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| The solder pads really are very small! (© 2026 Jos Verstraten) |
Specifications
To conclude this introduction to the DSO183, we have provided the manufacturer's specifications below.
- Sampling rate: 1.5 MSa/s
- Resolution: 12 bit
- Memory depth: 1,014 samples
- Analogue bandwidth: 500 kHz
- Input impedance: 1 MΩ // 20 pF
- Sensitivity setting: 10 mV/div ~ 5 V/div
- Input coupling: DC, AC, GND
- Maximum input voltage: 50 Vpeak-to-peak
- Time base setting: 500 s/div ~ 1 μs/div
- Trigger mode: auto, normal, single
- Trigger slope: rising or falling edge
- Display: 2.4 inch colour LCD, 320 by 240 pixels
- Supply voltage: 5 Vdc
- Supply current: less than 100 mA
- Dimensions: 118 mm x 76 mm x 12 mm (without housing)
- Weight: 45 g (without housing)
The electronics in the DSO183
The input amplifier
The diagram below shows the analogue circuit of the vertical amplifier. The three-position switch SW1B selects DC, AC or GND. This is followed by SW2B, a traditional passive 1/10/100 attenuator. Resistors R2 and R3 form the 1/10 attenuator, whilst resistors R4 and R5 form the 1/100 attenuator. Both resistive dividers are frequency-compensated by capacitors C4, C5 and C6. The two trimmers must be adjusted after assembly. It should be noted that no special measures have been taken to protect the input circuit against excessive voltage spikes. The design apparently relies entirely on the attenuating effect of resistors R1 and those of the voltage dividers.
Following this initial passive attenuator is the stage around U2A. This op-amp is configured as a buffer with a voltage gain of 1, a wide bandwidth, a very high input impedance and a very low output impedance. This buffer is terminated with a second resistive voltage divider R6, R7, R8. This is designed so low-impedance that capacitive compensation is not required.
The ADC in the microcontroller operates in unipolar mode. Consequently, the input signal must also be entirely unipolar. This is achieved by the circuit around U2D. The TL431 shunt voltage regulator (D2) generates a stable reference voltage of -2.5 V. This voltage is applied via resistor R11 to the inverting input of the op-amp U2D. The result is that the output of the op-amp is set to a positive reference voltage, around which the signal to be measured will vary. This is thus made entirely positive, so that the ADC can process it. The voltage gain of this stage is determined by resistors R9 and R10.
The microcontroller must, of course, know the positions of the three switches SW1B, SW2B and SW3B. Hence the sections SW1A, SW2A and SW3A, which send three voltage levels to the microcontroller: GND, AV+ and +1.65 V. This latter voltage is generated across the voltage dividers R42/R43, R50/R51 and R52/R53.
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| The complete input amplifier circuit. (© JYE Tech) |
The power supply
The simple power supply is shown in the figure below. A stable voltage of +3.3 V is derived from the +5 Vdc USB supply via U3. This powers the microcontroller, the display and the memory.
The two symmetrical analogue supply voltages are generated just as simply. The positive AV+ is derived directly from the USB supply and decoupled via a small RC network (R32/C24). For the negative supply AV-, U4, an SGM3207, is used. This is a charge pump which, with the aid of capacitors C25 and C26, generates a negative voltage from the positive voltage present at IN. This voltage is decoupled via R33 and C27.
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| The power supply circuits. (© JYE Tech) |
The sine wave generator
As an added convenience, the DSO183 provides a sine wave with a frequency of approximately 1 kHz and a peak-to-peak value of 1 V. This signal does not originate from the microcontroller, but is generated in analogue form by a third op-amp, U2C, from the TL084. A traditional Wien bridge has been constructed around this op-amp using the components R13, R14, C7, and C8. The attenuation of this feedback is compensated by the network comprising D3, D4, R15 and POT1. By turning POT1, you can adjust the circuit to generate a fairly smooth sine wave. The variable forward resistance of the two diodes D3 and D4 stabilises this set point.
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| The sine wave generator. (© JYE Tech) |
The triangle wave generator
This does, however, use a signal from the microcontroller, namely SQR. As shown in the figure below, this signal is first made symmetrical with respect to ground via C12. This is followed by a clipping to ±0.7 V via R20 and DN1. This signal is integrated by the fourth op-amp U2B from the TL084. The integration capacitor C9 is charged and discharged linearly via R17. The result is that the output voltage rises and falls linearly, producing a triangular waveform.
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| The triangle wave generator. (© JYE Tech) |
Building the DSO183
Assembling the circuit board
Following the 'Assembly Guide', this should not present too many problems. You start with the resistors, then the two diodes, the USB connector, the capacitors, the slide switches, the adjustment potentiometer, the BNC connector, the push-button switches, and you finish with the five pins for the output signals.
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| The fully assembled circuit board. (© 2026 Jos Verstraten) |
Adjustment
You can then check a few voltages using a small table in the manual. The next step is the adjustment, a series of steps that are also clearly described in the manual.
Just a quick note on the 'Clr Offset' section in the 'Assembly Guide'. This procedure detects and compensates for offset errors in the op-amps in the input amplifier. It works as follows. Open the menu by pressing and holding the 'SEL' button for more than two seconds. The menu is shown in the screenshot below.
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| The DSO183 menu. (© 2026 Jos Verstraten) |
Now select the 'Clr Offset' option by pressing 'SEL'. Then press the '+' key briefly and the screen below will appear on the display.
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| Initialising the 'Clr Offset' option. (© 2026 Jos Verstraten) |
You must set switches SW2 and SW3 to specific positions. The firmware measures and compensates for the offset for those positions. You must then, using identical screens as a guide, set the two switches to different positions until all positions have been cycled through and the offset compensation procedure is completed. In theory, the baseline on the screen should now be neatly centred on the screen for all switch positions. In practice, however, there is room for improvement, read on.
Assembling the 'housing'
This is also a piece of cake thanks to the screws provided and the image below.
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| Assembling the 'housing' around the circuit board. (© JYE Tech) |
Working with the JYE Tech DSO183
The display
The display shows only the absolutely essential information and, thanks to this decision by the software designers, is pleasantly uncluttered. It's a breath of fresh air compared to the screens of some competitors, which display completely superfluous details such as temperature, date and time!
In the top row, on the left is the operating mode 'Running' or 'Stopped' and on the right the trigger mode 'AUTO', 'NORM' or 'SING'. In the middle, you will see a slider indicating which samples stored in the memory are displayed on the screen.
This is followed by two frames in which you can record two numerical data from the signal. You can select these via the options in the 'Menu'. There is also an option to display all available numerical data on the screen, but we strongly advise against this. The standard setting is to select the RMS value and the frequency of the signal.
The yellow and purple arrows indicate the position of the zero line (yellow) and the trigger level (purple).
The bottom line shows, from left to right, the sensitivity, the time base setting and the AC or DC coupling. A neat and clear little screen, then!
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| The display of the DSO183. (© 2026 Jos Verstraten) |
The controls
Adjusting the sensitivity is a bit fiddly as you have to use two switches. With 'SEN1', you select '10 mV', '100 mV' or '1 V'. With 'SEN2', you select 'x1', 'x2' or 'x5'. The most sensitive setting is therefore 10 mV/div, and the least sensitive is 5 V/div.
The functions of the four push-buttons are very easy to learn.
- 'OK':
This confirms a menu selection or switches between 'Running' and 'Stopped'. - '+' and '-':
Selects an item from the menu or increases or decreases a value. - 'SEL':
This allows you to select one of six functions, the value of which you can then adjust using '+' and '-':
- The time base setting.
- The trigger level (purple triangle).
- The waveforms displayed on the screen.
- The trigger function.
- The trigger edge.
- The position of the zero line (yellow triangle).
The selected option is displayed on a light blue background.
Testing the JYE Tech DSO183
Preliminary remarks
In the following tests, our DSO183 is powered by a 5 Vdc power pack, and is therefore completely isolated from earth and the mains supply. Naturally, we verify the integrity of all signals displayed on the DSO183’s screen in parallel on our laboratory oscilloscope, an XDS2102A from Owon.
Twelve bit resolution?
The specifications state that this little oscilloscope digitises at 12 bit. That would mean the vertical resolution is very high and that the instantaneous value of the signal can be displayed in no fewer than 4,096 steps. The result would be a beautiful image, without the annoying staircase-like shape of digital oscilloscopes with much lower resolution. However, if you look at the previous image, you can see that this claim is nonsense. The sinusoidal voltage is displayed with the same distracting staircase-like approximation as on any 8 bit oscilloscope. Perhaps the signal is sampled internally at 12 bit resolution by the ADC in the microcontroller, but the display on the screen certainly does not do so. After all, those 4,096 steps simply cannot be displayed on a screen with a height of only 240 pixels.
In short, mentioning that 12 bit resolution is a meaningless marketing slogan!
Display of small and large sinusoidal voltages
Our first test displays a sine wave with a frequency of 1 kHz on the screen, varying in amplitude. We are interested in the digital noise that appears on the screen and, of course, in the accuracy of the display of the RMS values.
The result of this test is shown in the figure below. To summarise:
10 mV → 16 mV
100 mV → 0.10 V
1 V → 0.97 V
10 V → 9.76 V
In the first measurement, there is clearly a positive offset shift in the display, despite the calibration. This offset is likely the cause of the significant error in the display of the numerical value of the RMS voltage. A positive point is that there is no digital noise contamination in the display when measuring the 10 mV voltage.
When displaying the 10 V sine wave, a strange distortion occurs just below the signal’s zero crossing. We have indicated this with the red arrows. It appears as though the system is skipping a number of samples. This is, of course, a completely unacceptable error for an oscilloscope. After all, it means you cannot rely on what you see on the screen being an exact representation of the signal you are applying.
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| Measuring various amplitudes of a sinusoidal voltage. (© 2026 Jos Verstraten) |
Measuring the bandwidth
The bandwidth is the frequency at which the amplitude of a sine wave has dropped to 0.7 times the amplitude of an identical signal with a frequency of 1 kHz. This corresponds to a signal attenuation of 3 dB. According to the specifications, the bandwidth of this oscilloscope should be 500 kHz. We verify this by connecting a sine wave with a RMS value of exactly 1.00 V (measured with the DSO183) and a frequency of 1 kHz to the input, and then increasing the frequency of this signal until the oscilloscope measures an RMS value of 0.7 V. As shown in the oscillogram below, this occurs at a frequency of 314.8 kHz. The specified bandwidth is therefore, as is often the case with oscilloscopes, greatly exaggerated!
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| The -3 dB frequency of the DSO183. (© 2026 Jos Verstraten) |
The signal at 500 kHz
We are curious to see how the DSO183 performs at its specified bandwidth. Not much remains of an input signal with a RMS voltage of 1 V and a frequency of 500 kHz; see the oscillogram below. The DSO183 claims that the RMS value of the signal is only 0.15 V. The signal shape is also far from the ideal sine wave we apply at the input. Above the true -3 dB frequency of 300 kHz, the oscilloscope’s performance therefore deteriorates very rapidly.
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| The display of a 500 kHz sine wave. (© 2026 Jos Verstraten) |
The display of square-wave signals
Finally, we will briefly test the display of square-wave signals. With a measured bandwidth of 300 kHz, the display of a 10 kHz square wave should not be a problem; see the left-hand oscillogram. However, rise and fall times are already clearly visible, a phenomenon that can, of course, be explained by the presence of two op-amps in the signal path that are not particularly broadband.
With an ideal 100 kHz square wave at the input (right-hand oscillogram), the far from ideal rise and fall times play an even greater role, and the signal shape displayed on the screen is already clearly very distorted.
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| The display of 10 kHz and 100 kHz square waves. (© 2026 Jos Verstraten) |
DSO183 Oscilloscope Kit
