This circuit was found in a 1980s Signetics documentation. The integrated circuit is from the era. The circuit enables coded matrix control via a toggle switch.
In the figure we have a Texas Instruments circuit for TTL interfacing using discrete transistors. The two...
This circuit was found in Radio Electronics magazine from June 1963. The range is small and the...
The project presented in a 2009 documentation is intended for radio amateurs operating in the...