The power supply for this 1972 circuit must be symmetrical and the BC549 transistors. Care with the layout is important to avoid capturing tinnitus.
This tone generator for CW was found in a publication by Gernsback from 1960. The circuit makes use...
This circuit was obtained in an old US 1974 documentation when Nixie tube displays were common. The...
This circuit was found in an 80s National Semiconductor documentation. The configuration holds...