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.
September 2017 - Microchip's MCP6411 operational amplifiers for frequencies up to 1 MHz are in...
We found this circuit in a 70s publication. Transistors are general-purpose types of the time. The...
This receiver circuit was found in a Hands On Electronics from the 90s. The circuit uses a PLL...