DSO 138 DIY KIT (13801K)

This is a pretty decent kit.Let me break it down:1) The documentation was fairly decent. It actually came with step by step printed instructions.2) The PC board was good quality.3) The resistors are HARD to identify!!! This is the #1 reason this is not a 5 star review. You need to use a ohm meter.4) The thru hole barrels are a bit too small, which makes it harder to solder. Had a hard time with some of the components even though I used a high quality Weller WES51 iron. This is the #2 reason this is not a 5 star review.5) The oscilloscope worked the first time, which is important when building a kit.6) I was able to finish it is just a few hours.7) It’s not a full blown scope, but for 25 bucks??!! It is good for quick measurements, which is very common for my type of projects. For the price, you’d be hard pressed to get a soldering kit that has so much functionality and usefulness (for example the lame coin toss kit).

What a delightful little scope kit! All the parts were there, the instructions were excellent and it worked right off after assembling it. As for how well it works, it is really an audio band only scope. Between the op-amps for gain stages and the 10us maximum sweep time, it shows 20 kHz just fine but not much more. Like some others have mentioned, one of the trimmer caps acted funky when I tried to adjust it, although it was close to correct anyway so no biggie.This actually would have made an excellent evaluation board for ST micro, certainly more useful than their Nucleo series.The only real weakness I would mention is that the triggering could be better, although it works as well as any soundcard based PC app oscilloscope I have used. I ran mine off an old linear Radio Shack bench supply for the 9V source and no problems with startup or noise. The readout for rms, pk-pk voltage and frequency was amazingly close compared to an expensive Fluke 8050A meter that I compared it to. If someone sold a clear case for this, for say, $10, I would be the first to buy one!

Pretty good. Just better quality caps and trimmer caps and it would have been 5 stars.Works well up to 200KHz as advertized. I see quite a rounding of my square input as a result of the caps not being well balanced. The caps the unit ships with are not the greatest. Especially replace the 11 .1uF caps with tighter tolerance ones (cost like 1 dollar) and then the trimmer caps as others have reported dont always seem to do much to adjust.Another thing. Be very keen to supply a quality 9v input. You can use a 9v battery but once it drops below 8v your readings will go to sh*t. It would have been nice if it had a readout for its input supply voltage so that you could monitor this condition more easily.Still for 20$ it is an excellent product! Dont buy the SainSmart it is a knock off, the auto center and auto trigger features do not work and the readouts are not reliable. Buy the official JYE.Also for anyone else that is wondering the USB port currently doesnt do anything but may in a future firmware update.

The DSO138 Kit I purchased is an original kit manufactured by JYE. There are several counterfeit DSO138 kits being sold out there so check with the manufacturers web site to find retailers on Amazon that are selling the OEM kit(s). The JYE forum indicates a lot of problems with counterfeit kits, and for the price difference it's not worth the headaches they have caused DIY'ers.I verified with the retailer that the kit I was purchasing was the one with all the SMD parts pre-installed on the PCB (PN: 13803K). Even with all the SMD parts pre-installed this was a fun and simple kit to assemble. You will definitely need a low wattage (~ 25W), SMALL TIP, soldering iron for most of the assembly (plus a higher wattage iron just for the BNC and power connectors). The small tip iron (and fine size solder, e.g. .032") is essential since the spacing between some of the solder points is very small (especially the slide switches where I ended up soldering a short to ground). BTW, the JYE Forum was VERY helpful in assisting me in troubleshooting the one problem that resulted from the shorted SW. They nailed the problem on the initial diagnosis, and I got lucky finding the short the 1st place I looked based on their input.I separately purchased a clear acrylic case for the DSO138 which makes the whole kit a conversation starter when left out in the open. Note of caution on cases. If you purchase one buy some extra M3 nuts (or M3 nylon lock nuts) to hold the main PCB at a working distance from the "floating" push button stubs.Enjoy, I did!

I ordered this oscilloscope kit, and have already soldered it together! Be aware that you need a multimeter to measure each of the resistors. While the resistors are color coded, it is difficult to know which way to read the colors. So, a digital multimeter is a must. Be sure and prepare every item so you get all the right parts at the right spots on the board!I assembled this, and it worked the first time. Be sure and read the directions a few times, and have fun! The solder joints are pretty 'big' but it does take a little skill to ensure you get proper connections. If you have soldered on boards before, this kit is really straightforward.As a sidenote, be sure that you watch how you will attach the screen. As the screen is attached with three headers, it is important to get them as close as possible so the screen fits well. When i soldered mine, I ended up being a little off, so I ended up heating up the solder on the connectors to give it a much better fit.The instructions were in color and very easy to follow. Be sure to sort all the parts before you start!I am happy with this, and the few simple tests, shows it will work well for what I need it to do!