Found in American documentation from the 90s, this circuit can be applied to other operational ones. We found it in an EDN of the time. Next to the diagram is the response curve.
This is the simulation of a Ultrasound Receiver using the 741 IC, an operational amplifier....
The resonant circuit depends on the crystal frequency that can go up to a few megahertz. The...
With this circuit it is possible to select the upper or lower side band on an SSB transmission by...