I keep seeing people having trouble with this setup. Every time I go to RTTY Mode, something is not working. It seems that some of the parameters in MMTTY and in the Radio keep resetting themselves. There are some other posts on this blog that may help, but here are a few reminders.

Mode – AFSK or FSK?

I am NOT addressing the FSK Mode here, where you use the special ACC connections and “true” FSK is generated. That should actually be fairly easy and stable, once you have it configured.

If you are connecting only the USB Port (like me), you must use AFSK Mode, where tones are generated by the internal 7600 soundcard. You MUST use the “LSB-D1” Mode on the IC-7600, so use the “SSB” button to get to that Mode. You must set the parameter ACC/DATA1 MOD to “USB” and NOT the default which is “ACC”. For me, this keeps resetting itself when I power-down the Radio .

In MMTTY, You must set the TX and RX sources to your IC-7600 internal soundcard. You need to know the name that has been assigned, and it may not be obvious. For me, here are my soundcard names for the IC-7600 soundcard:

  1. Reception – Microphone (USB Audio CODEC)
  2. Transmission – Speakers (USB Audio CODEC)

Not very helpful names. I have heard you can change them and maybe I will get around to that someday.

A couple other things to check in MMTTY OPTIONS:

  1. Since you are using SSB Audio filters, you must set the “MARK” frequency in the Spectrum Window (or the DEMOD TAB) to something in that range. You can NOT use 2125 Hz. I am using 1445 Hz.
  2. TX TAB – PTT & FSK – set the PORT to “NONE”
  3. MISC TAB – Set Tx Port to “SOUND”

Those seem to be the most troublesome parameters for me. There are many others in MMTTY, and there is help available on the N1MM+ Site.