This 5.1 MHz circuit was found in a 1980s documentation. The frequency is given by the crystal and general purpose transistors can be used.
This circuit was obtained in an Argentine publication in 1976. It consists of a series voltage...
This protection circuit was obtained in a 1969 Electronic Design. The SCR can be the current...
With this circuit published in Radio Electronics magazine in September 1959, it is possible to use a...