This circuit is from an Electronics Now from the 90s. The circuit uses a power integrated circuit from the time that must be equipped with a heatsink. The power supply is 18 V.
This simple version of a function generator with the XR2206 was found in the May 1977 issue of...
In a modern version this circuit can use an LED in series with a resistor in place of the lamp. The...
This VFO was found in a 1980s documentation. The central frequency is given by the crystal and the...