This circuit from General Electric was found in a 1967 documentation. The SCR is of the time, as are the transistors, but equivalents can be used.
Found in a Radio Electronics from the 90s, this circuit generates a 1 kHz signal to serve as a...
This low noise circuit was obtained from a 1980s US RF publication. Transistors used are uncommon...
This circuit applies to other operational ones, other than the one indicated. The formulas next to the...