This circuit makes use of a stroboscopic tube, a component that no longer exists today. The circuit is from the 70's and can be adapted to use mains voltage.
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...