Sometimes it’s useful to know how to find the output impedance of unknown devices such as that of my cheap Chinese signal generator (MingHe MHS-5200A) and today I saw a youtube video from W2AEW which explains how it’s done. What we need to do is take two measurements of the output voltage. In my case I set my signal generator to a 2v sine wave at 5kHz. We want a low frequency sine wave so as the coax doesn’t start to affect our measurements with reflections and such.