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.
Found in Linear Technology documentation, this circuit drains only 70 uA of the monitored circuit....
120 degree lagged signals can be obtained with the simple configuration shown in the figure....
This circuit compares two light intensities, providing the indication on an analog instrument. The...