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.
Originally this circuit was indicated to be used in a garage door control, but it can be modified for...
This conventional oscillator with the 741 can be precisely adjusted to produce a 400 Hz signal. The...
This current-limited circuit was found in a Popular Electronics from the 90's. ...