Fldigi and the K3
Fldigi is currently the best Linux application for digital modes. It is being actively developed by David Freese , W1HKJ, and his productive team. A couple of days ago I upgraded my old 1.33 version to the recently released 2.10 version. The additions are significant, most notably the use of a psk viewer, which allows simultaneous psk traces to be decoded at once. Click on the thumbnail below to see my desktop when decoding signals on 7.070 MHz.
Below the psk viewer you can see the rig control which controls the K3 via the serial port. I am using the rigCAT interface to control the K3 rather than hamlib. This is because the rig control commands are in an rig.xml file which is easily edited. I took the basic K2 rig.xml file and did some minor modifications to tweak it for the K3. I will send the file on to Dave, W1HKJ, but feel free to contact me if you want me to send you the K3 rig.xml file.
When looking at the control of the K3 I did notice that currently the only computer control of the bandwidth of the bandpass filter is by switching the crystal filter. I suspect this will change at some point in a later firmware update.
If you run Linux and not tried FLdigi, then give it a try. If you do not run Linux you may want the W1HKJ’s EMCpup which is a live Linux distro, based on Puppy Linux, that is loaded with his applications that make it ideal for emergency communications. There is also a Windows application that W1HKJ has developed with Skip Teller, KH6TY, (of Digipan fame) called NBEMS which is targeted for emergency communications and compatible with EMCpup and its software.
I have not tried EMCpup or NBEMS yet, but if you have, feel free to add a comment with your experiences of these applications.