Steve,?
Hi. Just found your project. My HAB trackers are currently doing RTTY in 70cm band. Swapping the radio module is the only way to convert them to HF. For floaters, it is required we do HF or 2m APRS. Ordered a Si Adafruit board to start testing. At first glance, your code looks a bit naked on the GPS side of things. Will see what results I get.
73
