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 figure shows how to use a varicap in a conventional tuning circuit. The circuit may be an...
The CUT frequency for this filter is determined by the capacitors. The µA4138 is a quad version of...
The TTL 74123 integrated circuit consists of a monostable that can be configured to generate...