This CW circuit was found in a Radio Amateur Today from the 890s. The CMOS circuit must be powered by an isolated source and has different dash and dot timings.
This circuit was found in an American documentation from 1969. The circuit is a multi-indicator with...
This power supply was found in the 1996 Texas Instruments Linear Applications Manual. The circuit...
This receiver uses germanium PNP transistors that can be used from old disused devices. The...