Ever on the lookout for new test gear to add to my collection I stumbled across the XR2206-based function generator. These can be bought as a kit pretty cheaply from AliExpress or from eBay, they're easy to put together and use offering 1Hz - 1MHz of range through the use of some jumpers. It has two output terminals, one that gives a square wave and one that gives either a triangle or sine wave, depending on the position of a jumper. The heart of the device is an XR2206 which is an "obsolete" function generator chip with some pretty good specs and a low external parts count. I bought one of these kits because my ultra low THD sine generator (a Wien Bridge oscillator with a bulb) is fixed at ~1kHz and being able to steep the frequency (and use other waveforms) is a huge help in analysing a circuit My Ultra Low THD Oscillator After building the kit I fired up Arta to measure the THD, the results were... disappointing, 2.7% if you set the amplitude right but around 4-5% m...
My ramblings on a variety of topics.