Even if you haven’t used one, you’ve probably seen the numerous ... [Qrp-Gaijin] shows how to do it with a single transistor. You can see some videos of the results, below.

The chances are that many of you will have made an FM “bug” style transmitter, a simple one-transistor oscillator usually driven by a small electret microphone. It’s also ...

Figure 1 shows a variation on a sine wave oscillator, it uses just two transistors and a single variable resistor ... Usually this filter is implemented around an operational amplifier, it can also be ...