This 1924 receiver uses a battery for the tube filaments and a high voltage battery for the amplifier and detector circuit. The speaker is kind of high impedance era.
This circuit was proposed by a 1965 Electronic Design. Its purpose is to widen the line transients...
We found this receiver in old documentation. The transistor is made of germanium and the...
This simple battery tester uses two transistors to drive LEDs of different colors, indicating the...