Just a correction on the Pi-zero, Jerry. I do run PSK on a Pi-zero quite well, but not with Fldigi. I am using a program called LinPSK, written especially for Linux systems a decade or so ago, but recently (like yesterday) updated by the author. I tried Fldigi, but it is far too much for the little Pi and it would just freeze up, so that is why I searched for an alternative and found LinPSK.
I do run WSJT-X on the Pi-zero, but it is marginal as the decode time is such that the next transmission cycle has usually started before it is done. I have been whittling away at that by eliminating background programs and overclocking the Pi, and I can make contacts, but it still needs to be a bit faster to avoid the repeats that happen at least once with each QSO. The Pi-zero is not the best for ham programs, but a computer the size of a stick of gum for a portable application is attractive and, well, I already had the zero looking for an application. The whole digital interface could easily fit inside the uBitX case with this little thing.
=Vic=
Vic WA4THR