[Elecraft] K-Line on digital modes

[Doug Person via Elecraft]

I have a full K-line setup (K3, P3, KPA500, KAT500) and I've been trying 
to get the K3 working on digital modes.  I can't seem to get it to 
transmit.  Using the K3 Utility, I can verify the K3 at a particular com 
port.  Firmware updates work fine.  I can read PSK in terminal mode.  
But, when I click on the transmit button, the K3 doesn't switch to 
transmit.  I have the PTT menu option set to DTR and, in fact tried 
every variation of DTR and RTS with no difference.  I have tried both 
FTDI USB-to-Serial adapters and a genuine, built-in serial port - all of 
which work on everything else.  I'm missing something I guess.  I just 
don't see it.

Doug -- K0DXV