@equinox1 - You make some interesting assumptions. My experience with the Coolterm program and usb/serial converters is that the status indicators correctly report the state of the serial interface as communicated by the converter. Have you had situations when Coolterm did not do this correctly?
I said that I could see TX activity only, which could mean either the DX wasn't talking or the FTDI converter wasn't listening. I rule neither possibility out at this stage. I completely agree with you, connecting the converter's TX and RX lines will be an absolute test, locating the fault in either the converter or the DX. Haven't had the opportunity to do it yet, but it's definitely my first step.
If you felt as if I was not listening to you, that definitely was not the case, so perhaps next time give me the benefit of the doubt, ok?