This source was originally suggested by Delco in a 1969 documentation to power amplifiers up to 50 W. The transistors are of the time admitting modern equivalents.
This circuit was found in an old documentation and can be implemented with BC549 transistors. The...
This mid-waveband receiver was found in a book on transistors from 1954. The antenna coil is of...
Old multimeters used a 22.5 V battery for high resistance measurements. If you have one, you...