This oscillator for the fifth overtone of a crystal was found in a Radio Electronics magazine from May 1970. Transistors are RF types, and the transistor determines the maximum frequency achieved.
This latching alarm circuit using relays was found in American documentation. Sensors are...
Pressing and releasing S1 remains one of the neon lamps. Which one will be, it is not possible to...
Found in an Electronic Design, this small power source uses a battery as a voltage reference,...