[Elecraft] RTTY Problems on K3

[k3sv at pa.net]

I am fairly new to the K3 but have no problems setting up N1MM and  
other software, getting things to work properly. My problem is I  
cannot get RTTY to send/TX. I have made a homebrew interface with  
optoisolators for both the FSK line and the PTT line. I'm going from a  
separate serial port, pins 3 and 7, for FSK and PTT, to the Assy(15  
pin) connector. To pins 1 for FSK, 4 for PTT and 5 for ground.

When I run MMTTY I cannot get the rig to key. If I switch to SSB or CW  
and use the CAT line to work the PTT, no problem. If I switch to RTTY  
and try to use the CAT line it will not key the TX. I've tried a  
variety of setting in MMTTY and get no TX. I have a 1000MP set up with  
a similar homebrew interface and have no issues.

Can anyone shed some help on me?

73 Bill K3SV