Suggested by a 1968 documentation, this circuit limits the current of a regulator and can be adapted to other currents. The transistors are from the era.
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...