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.
Frequency modulated signals up to 500 kHz can be decoded with the PLL we show. The demodulated signal...
When operating near a medium wave radio, the signal frequency changes and this can be heard on the...
This 1967 Electronics World circuit is suitable for frequencies up to 1 MHz. The setting applies...