This sensitive three-transistor circuit was found in Electronics Now magazine and is earphone-readable. The tuned range depends on the coil.
We find this conventional amplifier with complementary transistors in a 1987 documentation. The circuit...
The circuit is a multivibrator version using two NPN general purpose transistor. This circuit can...
The circuit shown in the figure is suggested by Intersil (www.intersil.com) and makes use of the...