Found in an old Radio Electronics, this circuit applies to frequency meters for frequencies up to 100 MHz. The input impedance is in the order of 1 M ohm.
This sinusoidal oscillator was found in Radio Electronics in 1989. It uses a 741, but other...
This is the circuit of a commercial flash from the 60’s. The circuit was published by the march...
This circuit is suggested by Motorola in its 1990 Linear Databook. The integrated circuit is no...