We have seen this signal generator come up as "suggested" in our Amazon account from time to time. Finally, the Amazon marketing engine combined with COVID cabin fever persuaded us to shell out the $10US and give the kit a try.
$10 gets you a lot and not so much both at the same time. First off, the directions are not very well written, but the kit is simply enough that they don't need to be. We did have to ohm out the PCB just to verify that the NEG terminal for the electrolytic caps went into the "hashed" marked hole. After about 20 minutes the kit was ready test out. The results.....
We took measurements with an oscilloscope for each setting. Instead of putting up a bunch of boring sin, triangle, and square wave pics we will just state that the rig works as expected. ONE CAVEAT: THIS ONLY SEEMS TO BE TRUE WHEN YOU POWER THE RIG WITH 9VDC. Also, adjusting the "Amp" knob can really effect the quality of the output signal. There is a sweet spot on the "Amp" setting, but without a scope I'm not sure how you could find it. Another odd behavior; a square wave will produce an almost 9V output. The sin and triangle waves max out at about half that.
Here are our findings:
So..... if you need a low end sig gen this kit does work. It's cheap to buy. It's easy and fun to build up. But, be aware that without a scope you will not have a way to know the exact output frequency and output voltage or if the output signal is being clipped or otherwise deformed.