This circuit is from a 1968 documentation using one of the first integrated circuits available at the time, the TAA370. The circuit is powered by 1.3 V using a 200 ohm handset.
This three-transistor amplifier uses a JFET at the input to increase the input impedance. The...
This two-transistor MW radio was found in a publication from 1958. It uses one of the oldest type...
This simple circuit was suggested by the Electronics Handbook Volume XIII 1993. LED D1 emits light for...