This circuit, which can serve as a reference for restorations, was found in the October 1989 issue of Radio Electronics magazine. The circuit uses a 5-digit display and a dedicated integrated circuit.
This power source, obtained in a 1973 publication, suggests the use of partially burned germanium...
This circuit was obtained from an Electronic Design from 1964. Transistors admit modern...
The circuit is from the 1994 National Semiconductor Linear Applications Handbook but can be...