Found in 90's Electronic Engineering this circuit can be used to measure phase angles between two signals from 0 to 180 degrees. The components used admit modern equivalents.
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...