This symmetrical power supply uses two old filament transformers. The circuit was obtained in a documentation from the 80's and the diodes can be 1N4002.
This experimental telegraphic communication system can have wires connecting to the handset of...
Scratch is the scratching noise that occurs mainly with old records. This high frequency noise is...
This short-range circuit can act as a wireless microphone. We got the schematic and the printed...