This crystal or galena radio is one of the many versions available on this website. This is from a documentation from the 70s. The coil is formed by 50 + 50 turns of wire 28 in a ferrite rod.
The components of this circuit are still common today. The circuit is from a 1967 publication by...
The circuit shown enables dynamic diode testing with an oscilloscope. We found this configuration in a...
This is a traditional configuration of a transistor amplifier with complementary transistors that can be...