This very low frequency circuit was found in a 1964 Electronic Design. Transistors may be modern equivalents. The filter is low pass type.
Found in the July 1968 Supertena Bulletin of a Popular Electronics, this receiver makes use of the...
This switching source was obtained in a 1976 National Semiconductor manual. For the indicated...
This configuration appears several times on this site. The circuit can generate a 100 kHz or other...