I apologize - I deleted my message that started these comments once I realized the .xz file was compressed. I used 7-zip to uncompress it (internet search told me how). Etcher loads the resulting .img file without errors or problems and it does boot on my RPi 3 B+ with DRAWS attached. aplay -l shows the URDC card. Using N7NIX's update process (prog_refresh.sh) updates the scripts and shows all the programs are at current versions.
My other test is to run GPSMON to verify that GPSD and the GPS are working. When I first used the image, GPSMON worked. But after I expanded the image for my 32GB card, GPSMON no longer works. GPSD starts but does not allow GPSMON to work.
I have no clue why after expanding the image GPSD/GPSMON no longer works - I ran N7NIX's gp_install.sh script but that did not fix the problems.
I did not try any other programs.
Suggestions are welcome - I do have my own image that works and is fully expanded.
Edd - KD5M