For the record, and in case anybody else is having my problem, the K3/N1MM Configuration that works for me is: Com 1, Elecraft K3, a check in CW/Other, SET 4800, n, 8, 1, DTR=CW, RTS=PTT, TX=1. SO1V is checked. The K3 Config, PTT--KEY is set to RTS-DTR. Many thanks to N2BC, W4TV and others. 73, Dave