As I was casually skipping through my emails, I noticed this kit in a Banggood newsletter I received some weeks ago. The JEY Tech DSO 138 DIY digital oscilloscope kit kit was included in a small section with other DIY kits between useless $.99 gadgets, weird Chinese clothes and some $199 8-core multi-SIM smartphones.

Long story short, I purchased most of the kits on the Banggood wholesale shop, I couldn’t help myself. The list of kits I purchased includes an oscilloscope, a signal generator and an oscillator / frequency meter kit. I didn’t stop there, I also got two other kits, an audio spectrum analyzer and a 4-digit clock kit. I do not own any kind of equipment like this, neither an oscilloscope nor any kind of frequency generator or meter. Chances are I might use them a couple of times, mostly to familiarize myself with those tools but I couldn’t say no to DIY kits.

The system informed me that the items aren’t in the same warehouse and that they will be dispatched separately. No probs. This week, the DSO 138 kit arrived in the mail. Ιτ was well packaged and even included instructions on how to build it, soldering tips and basic troubleshooting guidelines. I was surprised, to be honest and had to wait until the weekend to build it. And so did I!

What went well

The JEY Tech DSO 138 DIY digital oscilloscope kit has well-defined instructions, everything is labeled both on the board’s silkscreen and on a separate schematic that was included in the package. It worked on the first try too, that was unexpected considering it includes soldering SMD components. The instructions categorize components based on type but do not mention the SMD parts. During my research for this article, I discovered that there are two versions of the kit available, one has all the SMD components prepopulated and the latter only the MCU. I wish I did a better research and had purchased the pre-populated SMD version.

What went bad

I really hope they had labelled the resistors in the kit. It took me about an hour to measure and categorize them. Initially I started categorizing them by their color codes, but got bored after the second resistor. Finally, a multimeter with auto-scaling was used.

The kit has way too many components. I know this is a full-blown oscilloscope, but it took me about 6 hours non-stop to build this thing! I enjoyed it at first, but got really tired at the end. Maybe I shouldn’t leave the SMD parts soldering last. Or I should split it into two parts. The results were worth it though :)

Opinion time

Is it worth the money? Should you try it? For 22.99€, I believe it is really worth both the money and the time it requires. Keep in mind you will need a good soldering iron (preferably a soldering station), a steady hand, ability to follow the instructions and a lot of patience. Also, while you are waiting for the kit to arrive in the mail, you should practice your soldering skills on an old PCB or a soldering kit.

Unfortunately I can’t comment on the devices specifications as I don’t have any background knowledge with these devices. Heck, I’m not even sure how this thing works yet. I have run the calibration steps included in the documents and now I’m fiddling with the built-in signal generator it includes for testing. I have also used it for audio visualization :)