Yaesu CAT/Digital Interface

CAT Control and AFSK soundcard audio interfacing for the FT-897D (and FT_857)

A CAT/Digital Interface for FT-897D

The CAT portion provides rig control from a PC, and the Digital portion connects the soundcard to rig audio.

Inside the CAT/Digital Interface

Power (+13.8V) is provided on the FT-897D data port; the MAX-232 handles RS_232 Level conversion.

CAT/Digital Interface Schematic

Schematic

Note that for use with Ham Radio Deluxe, neither the RTS nor the DTR connection nor the Opto-Isolator are needed. I discovered this when the rig was connected to a laptop during power on the DTS/RTS lines are not well behaved, causing a PTT at the rig. Ham Radio Deluxe is able to key the rig via CAT control, so this is not needed, but the DDTS/RTS mechanism via the opto-isolator is provided for other software which may not use PTT via CAT command.