**The $20 Oscilloscope Kits: Are They Worth It?**

If you're into electronics, chances are you already know that an oscilloscope is a crucial tool for understanding circuits and creating your own. However, if you just want to measure the duty cycle of your PWM signal without all the fancy mathematical functions like FFT or cursor control, a $400 Rigol scope might not be worth the investment.

Fortunately, cheap $20 oscilloscope kits can be found nearly everywhere nowadays, offering decent features for the price. So, let's take a closer look at one such kit and see if it's really worth it.

**Unboxing the Kit**

First things first, let's have a look at what's inside the package. We've got one bag with plenty of components to solder, a BNC to alligator clips test leads, a 2.4-inch TFT LCD display, and finally, the main PCB which has an ARM-based STM32F as its core. However, I couldn't find any manual or instructions in the box, so I had to search for them elsewhere.

After printing out the instructions from the original manufacturer, Jye Tech, I began assembling my components into separate piles. With a steady hand and some patience, I managed to solder the SMD components onto the board using a chisel tip that wasn't the best for the job.

**Assembling the Oscilloscope**

I used a schematic to identify which resistor value belonged to which pads, but it's not necessary to do so. Instead, I simply ignored the fact that Jye Tech offers a surface mount assembly guide and soldered the op-amp IC incorrectly during my first attempt. After flipping the orientation around, I managed to get everything working.

I measured the resistance of the through-hole resistors, put them in their correct places on the board, and soldered them into position. The same procedure was repeated for the capacitors, inductors, transistors, switches, and other complementary parts.

**Adding Power and Testing**

After three hours of assembly, I finally soldered male headers to the TFT display and added two additional wires to power it to my lab bench power supply set to 9 volts. The first successful voltage check was followed by a short circuit of the jumper plug-in, and then I could enjoy the first boot-up of my new oscilloscope.

**Features and Performance**

On the left side of the oscilloscope, we can see the switches for the coupling modes and sensitivity settings. Coupling mode removes the DC component from your signal, while ground coupling connects your signal input to ground. This is a good opportunity to adjust the line to the middle of the display.

Tuning the offsets, trigger voltage, or horizontal position is relatively slow and sometimes annoying due to the four-button control. The sensitivity switches offer a range of 10 millivolts up to 5 volts per division, which is definitely sufficient for hobbyists.

The time base goes down to 10 microseconds per division, but I found it not very practical. However, with some practice, you can still get usable measurements with frequencies above 100 kHz.

**Real-World Performance**

To test the oscilloscope's performance, I connected the alligator clips to my frequency generator. At 100 kHz, it worked fine, but as I increased the frequency up to 200 kHz and beyond, it started acting a bit crazy and wasn't usable for measurements.

A standard DSO would have no problem with these frequencies, but this $20 kit does its job just fine for simple things like finding out the duty cycle of your Arduino or other low-frequency periodic signals. It can even save one reading and spit it out whenever you want, which is a nice bonus.

**Conclusion**

All in all, I do like the kits for $20. You get a lot of features that are not only helpful in hobbyist electronics projects but also great preparation when it comes to using the real deal. The low current draw of roughly 110 milliamps makes it easily powerable by a 9-volt battery, which could be a future project.

If you're looking for an affordable oscilloscope kit and don't mind doing some soldering yourself, this might be worth considering. Just be aware that it may not have the same level of performance as more expensive models.

WEBVTTKind: captionsLanguage: enif you are into electronicsThen you probably already know that an oscilloscope is an indispensable tool when it comes to understanding circuits or creating your own.But my Rigol scope here or its improved successor is not really worth the$400 if you just want to measure the duty cycle of your pwm signal and don't care for the fancymathematical functions like fft or for example cursor controlThankfully though cheap $20 oscilloscope kits can be found nearly everywhere nowadays and they offer decent features for the priceSo in this video let's find out whether such kits are really worth it, or whether you should throw them out the windowLet's get startedFirst off let's have a look at the insides of the packageWe got one bag with plenty of components to solder , a BNC to alligator clips test leads , a 2.4 inch tftLCD display, and finally the main PCB which has an arm basedStm32F as a core, but what I missed inside the package was a manual or some kind of instructionsI found those eventually on the side of the original manufacturer jye tech and after printing them outI assorted my components into separate piles and turned on my soldering ironThe chisel tip I'm using here is not the best one for the jobBut through the help of a steady hand tweezers and tons and tons of patience the smd soldering was not that difficultSimply put a bit of solder on both pads ,bring the resistor near them solder one side in place and then the other oneby heating up both pads fast alternating the component almost finds the perfect spot by itselfI used this schematic to identify which resistor value belongs to which pads, but you don't have to do thisI simply ignored the fact that jye tech offers a surface mount assembly guideThat is also the reason why I soldered the op-amp IC incorrectly during my first tryI had to flip the orientation around at the end of the buildGenius, I know after all those end partsI measured the resistance of the through-hole resistors, put them in a fitting placeSoldered them to the board and snipped off the excess leads this procedure was pretty much the same for the capacitors , inductorsTransistorsswitches and all the other complementary partsafter three hours of this madnessI soldered male headers to the tft display and added two additionalWires to the PCB in order to power it to my lab bench power supply which was set to 9 voltsAfter a first successful voltage check I shorted the jumper four plugged in my display and enjoyed the first boot up of my newOscilloscope , on the left side we can see the switches for the coupling modes and the sensitivityin case you didn't know it yet the ACCoupling removes the DC component of your signal and the ground coupling connects your signal input to groundWhich is a good opportunity to adjust the line to the middle of the displayBut tuning the offsets the trigger voltage or the horizontal position is rather slow and sometimes even annoyingbecause of the four button controlthe two sensitivity switches lower voltage range of 10 millivolts up to 5 volts per divisionWhich is definitely good enough for hobbyists.The time base goes down up to 10 microseconds per divisionbut to give you a more practical example let's connect the alligator clips to my frequency generator asYou can see you're working with 100 Kilohertz signal is still possibleBut not a pleasure , the built-in measurement readouts also seem to work fine with this frequencyBut as you go up to 200 Kilohertz and BeyondIt's starting to Act a bit crazyAnd it's certainly not usable for measurements a standard DSO on the other hands would have no problem of thatBut for simple things like finding out the duty cycle of your Arduinoor other low-frequent periodic signalsIt does the job just fine it can even save one reading and spit it out whenever you wantWhich is a nice bonus.ok let's one to turn on or offOperations like charging up a capacitorI simply change the trigger mode to single and set the trigger voltage to around nine voltsNow if I charge the capacitor without a resistor the output of my two oscilloscopes are pretty similarbut once I started to charge it slowly through resistor the $20 kits refuses to trigger correctly andeven if a does triggerI cannot change the time base during the hold modeWhich is a pain in the ass because this way I have to scroll through the horizontal position and that takes foreverBut all in all I do like the kits for $20 you get a lot of featuresWhich are not only helpful to in Hobbyist electronics projectsBut also great preparation when it comes to using the real deal and with its low current draw of roughly110 milliamps it can easily be powered by 9-volt battery to make a portable , which might be a future projectAnyway until then don't forget to like share and subscribeCheck out the description if you want to buy one of those kits and support my channel simultaneouslystay creative, and I will see you next time