Bob, You're right about DX4WIN 6.01 following the standard. I looked at the documentation again and read it correctly this time. Thanks. I still have a problem. SO2R seems to working correctly. Radio control is switched at the appropriate times. The correct frequencies and modes are sent to the software, etc, but I still get a constant sidetone on the selected radio no matter what I do, as long as two radios are defined. In the File|Preferences|Control section my only options are LPT1 for CW Keyer Interface and LPT1 for Radio 1/2 signal. My control box is connected to LPT1 and works fine with other software. I'd like to find out if anyone else has used 6.01 with a DX Doubler.
Thanks again, Roger, W1EM