First, I’d like to thank everyone who offered suggestions to help me get my K3 working with WSJTX without using CAT control. Your input and encouragement were much appreciated.
1. First, setting the Rig to “None” under the Radio tab in WSJTX was a HUGE step forward. The post/article I read about using the K3 without CAT never mentioned NOT to enter K3 in the Rig menu and instead to select None. Seems obvious in retrospect but it took me hours of fiddling and a good nights sleep before it finally dawned on me this morning.
2. Then, selecting a different Speaker output under Windows made the tone I was then hearing from the computer speakers disappear. Turns out the audio was (incorrectly) being routed to the computer speakers instead of to the K3. This problem did not become apparent until I solved problem number 1 above.
3. Finally, after setting 1 and 2 correctly, changing the Output to “Both” instead of “Mono” under the Audio tab in WSJTX would put the K3 in TX and all was well.
All the other usual settings (Data A mode, Line In, etc. etc.) had been set correctly.
I was like a blind man stumbling in the dark.
The KEY was when I finally realized the Rig Control Error message I kept getting (which prevented me from seeing problems 2 and 3) was because it was impossible for WSJTX to communicate with the K3 without CAT so I needed to set the Rig to None. DUH, but NOBODY suggested that could be the problem. Lesson learned when trying to use a K3 WITHOUT CAT control.
If I had had the proper interface cable in the first place that would never have been an issue, but that’s been ordered.
I learned a lot but it was painful!
BTW - none of the problems I had had anything to do with the K3 - They were all errors in the settings for Windows and WSJTX!
BTW- Although I am using the internal sound card in Windows 10, I went into the Sound menu and changed a sound setting to “no Windows sounds” so sounds generated by the computer are not transmitted with the audio generated by WSJTX.
Thanks again everyone for your help!