This 800 Hz sinusoidal oscillator was found in a 1970s American documentation. The transistor supports a modern general-purpose equivalent. The frequency is given by the RC network that can be changed.
This stereo preamp uses only two germanium transistors. The circuit was found in old documentation using...
When the fuse blows, the neon lamp flashes at a frequency determined by the capacitor. This...
Using an operational amplifier at the time, this circuit was found in documentation from the...