I just used Ed K3HTK's auto fldigi install script to install fldigi on my Raspberry Pi 3. The script works very well, I have my Pi connected to my KX3 - you can find the script at:  http://indyham.com/news/fldigi-install-script-for-raspberry-pi-latest-version-3-23-12/ . FLDIGI is a free program that offers many digital modes including PSK31, RTTY, Hell, MT63, Olivia and even CW. Versions are available for Windows, Apple OS X and Linux. You can download fldigi from :  https://sourceforge.net/projects/fldigi/files/fldigi/

73, AL - VE3RRD