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 filter was found in an 80's English publication. However, it can be implemented with modern...
This circuit, which can be used as a shield, was found in old documentation. The circuit must be...
Found in Philips documentation from 1968 this circuit operates at frequencies up to 10 MHz with 76...