This circuit was found in Mullard's transistor application manual from 1960. More modern transistors can be used. The zener diodes used have the indicated voltages.
This optically coupled circuit was found in the February 1968 Radio Electronics magazine. The...
We found this circuit in the April 1978 issue of Radio Electronics magazine. The power supply must...
This circuit supports several sets of coils and can oscillate from 1 to 44 MHz. The transistor is an old...