This circuit, which can be built with several CMOS gates, was found in the March 1996 issue of Electronics Now magazine. The circuit has the base frequency determined by R1 and C1.
This circuit uses a CA3140, an operational amplifier with FETs in the input stages. Equivalent can be...
Found in a Popular Electronics from the 90s, this circuit has a configuration that has been widely...
This circuit was found in an American 80s circuit manual. The components used are unusual. The...