WI9WI prefers AFSK with PC sound card cabled directly to the K3, and logger either N1MM or Writelog running RTTY with MMTTY program.

Cabling (13 Feb 2023):

Stereo mini plug from PC audio out looks like (((( with an out arrow through them to back of K3 Line In Mono. Second cable from K3 front panel headphones audio out to PC audio in (microphone jack, icon looks like a boomset). Permanent and well-labeled cables installed 13 Feb 2023.

Not well organized notes from WI9WI:

N1MM: Window digital interface; K3 TX data; AFSK A 2125 (or 1700 centered in shift knob); MIC SEL LIN IN

2125 (1700)  170  60  70

Click UOS and NET but not SQ (Unshift on Space)

BW .600 or .500

Interface MMTTY

Setup Tab Setup, RTTY interface MMTTY, Profiles Standard RTTY

Options 5 bit LTR RX 1.42

Sound card Tab: IMP Jack MIC Realtek Hdph Realtek

N1MM: Dig Modes AFSK; C;\MMTTY.exe MMTTY path; Digitan F keys need to be set up in N1MM