Found in an ancient American documentation, this circuit can generate signals up to 40 MHz for a Z80, microcontroller widely used at the time. The circuit must be powered with 5 V and also serves as a shield.
This is a typical common emitter amplifier stage configuration. The transistor can be used...
Based on common components, this circuit was found in an English publication. The circuit is...
Found in a Popular Electronics from the 90s, this theremin is played by the position of the hand...