This commercial radio with 3 earphone listening transistors was manufactured in Japan in the 1960s. The medium-wave circuit uses germanium transistors and is powered by a 9 V battery.
This simple calibration circuit consists of a crystal oscillator that generates an accurate 100 kHz...
This circuit produces a low frequency magnetic field used in old inductive remote controls with a...
We found this circuit in a European publication from the 1970s. The transistor is made of...