This circuit uses two diodes in a doubling configuration to receive medium-wave range signals. The phone is crystal. We found it in a 1968 American documentation.
This analog ammeter circuit was found in documentation from the 1980s. The components admit...
This conventional Hartley oscillator circuit with an audio output transformer was found in a...
This bar or moving point indicator (bargraph) employs the LM3914 and can excite 10 LEDs, of any...