This circuit with a dual power supply generates sinusoidal, triangular and rectangular signals. We found it in the magazine Electronics Now of January 1996. The frequency goes up to a few megahertz.
The figure shows how to implement an alarm buzzer in an LM3914 to warn about crossing the scale...
This circuit can act as a shield being controlled by a microcontroller by pin 1 or 2. The...
This circuit was obtained from a 1980's QST magazine. The circuit can generate 1 to 15 MHz signals...