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.
The integrated circuit used in this filter is like to a double 741 and must be powered by a...
This Hartley telegraphy oscillator operates with the transmitter signal generating a tone in a...
This circuit, which appears at other points on this site, can be designed with both 4011 and 4001...