This circuit was found in a Signetics documentation from the 1980s. Next to the figure are the waveforms of the generated signals. The transistor admits equivalent.
This circuit was obtained from Linear Applications Handbook from National Semiconductor of 1994. It...
This circuit is from a 1974 publication, but it can still be easily assembled today with BC548...
This short-range, medium-wave transmitter was found in a 1966 documentation. The transistors are...