We found this circuit in a spy book from the 90s. Transistors admit equivalents and the coil can be designed as in the CB19425E project. Power is provided by cells or 9 V battery.
This simple oscillator with just one transistor has a frequency determined by the characteristics of the...
This Zero Crossing Detector was found in a 1972 RCA manual, but it can be made using any modern...
The circuit shown was found in a Japanese publication from the 1960s. Transistors can be...