This automotive circuit was obtained from an 80's schematic from the integrated circuit factory itself. The voltage regulator is still common, but the operational amplifier is of the time.
I got this circuit from an English magazine from 1977. It can still be easily assembled, as the...
This simple circuit for the mid-wave range was found in documentation from the 90s. The circuit uses...
This RCA circuit has current limitation. The circuit is from an ancient American documentation making...