FSK audio band modem with CD4046 PLL

Prototype of a FKS audio band modem with 3x CD4046 PLL ICs:
It is a complete full duplex RX/TX module with TTL input (its twin will soon arrive).

  • Maximum bitrate: 80- 100 bit/s
  • Unmodulated carrier: 1800Hz
  • Modulated carrier: 2100Hz

Schematics are coming. (most of the work is based upon application notes and examples found on the datasheets)