The FET can be a BF245, and the other transistors can be the BC548 and BC558 in this simple AM receiver. Adjust R4 for the best sound. The coil has 20 + 60 turns of wire 28 in a ferrite rod.
This circuit is from an old publication from 1977 and can be implemented with more modern...
This basic buffer circuit can be implemented with other operational amplifiers. The circuit is...
This circuit can be applied to other 3-terminal regulators and equivalent transistors can be used....