This is a traditional 741 configuration with gain close to 100. We found it in the December 1972 Radio Electronics magazine. The power source must be dual.
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...