Hi Larry - I've been playing around some with the beta builds, both from the image and building from source. I'm not as proficient as the people doing the coding, but as far as I can tell, the only way to turn the logging on or off at this point is when the software is compiled. Even with the logging on, though, it would still take the stratux several hours to accumulate a log large enough to fill up the micro SD card.
If you are able to connect a console (like Terminal in OS X) to the RPi with an ethernet cable, you can try logging in with something like "ssh
[email protected]" (that's the default IP address, AFIK). The default password is raspberry. If you get logged in OK, you can try looking at the logs with "ls -al /var/log". You'd see a listing of the log files for the RPi, including a few for the stratux. You can try deleting the UAT log (the one that would grow the fastest with a single SDR antenna) with "sudo rm -f /var/log/stratux-uat.log". Then do "ls -al /var/log" to see if the UAT log has in fact gone away. You'd probably have to restart the Rpi to get stratux happily running and logging away again (restart it with "sudo shutdown -r 0"), but I'm not sure if it needs the restart.
As I said, I'm learning this as I go, so YMMV! I've started over from scratch on the SD card a few times while experimenting...!