There are other solutions around for WSPR (like the Ultimate 3 kit from Hans Summers - excellent I am told) but I have had Wolf's 10m 500mW, fully stand-alone, WSPR beacon (WSPR-AXE-CW) running more or less continuously for 6 months now. This fits in a small Altoids sized box and needs no PC at all. The frequency is randomised but always on TX. My antenna is a 3 band low wire and certainly not the best for 10m. Despite this, it has been copied in the USA most days for months and has been spotted in every continent on the planet including Antarctica and Australia. If I am around, the 10m WSPR beacon is usually on. If you are after a fully stand-alone WSPR beacon for 30m, 20m or 10m these beacons are on a single PCB and work well. As the photo shows, the board is simple and the kit comes with a pre-programmed chip with your callsign, locator and power ready for use.