This blocking oscillator configuration was found in a 1964 American book. The circuit can be designed with modern transistors and the frequency depends on the transformer.
The Variable Frequency Oscillator (VFO) or Variable Frequency Oscillator shown in the figure can...
This circuit is from an English publication from 1978, but it can be assembled with BC548 for TR2...
This circuit slows down a pulse applied to its input. The delay depends on the capacitor and...