The capacitor used in this circuit can have values between 5 and 30 uF. The circuit is of old documentation for radio amateurs. Observe the special source used in the supply.
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...