This space mark demodulator for FSK signals was found in an American telecommunication documentation from the 1980s. The circuit operates with 2025 Hz and 225 Hz mark space signals.
This stage was found in a 1964 Electronic Design. The transistors are of the time and the shape of...
The figure shows how to obtain clocks in phase opposition using the 4013 IC. The circuit is from a...
This circuit was found in a 1977 publication, but it can be easily assembled, although unijunction...