It looks like I have solved the problems I have had with PuTTY. As I mentioned yesterday, I am a total PC dummy and have never had occasion to use a terminal emulator before. I looked for guidance on the internet and was taken to a Computer Weekly page that was (for me) useless gobbledegook.
In total fairness to Hans of QRP Labs, I think the instructions in the QMX (not QMX+) operating manual are very clear for Linux users, but perhaps a few words for Windows users would make things totally clear that you have to choose "serial" and put in the COM port number. Also, I had to plug the USB cable in after waiting about 10 seconds for the QMX+ to be recognised (I think!).
Once I quit PuTTY I shall see if the new audio levels are better on the higher bands.
