@dl5psy I've actually dont this before and it is rather common on weather balloons to have an aprs digipeater.
Works great you just need a relatively large balloon if your antenna has any mass to it.
@freemo Yeah, weather balloons + ham radio is also something that has been done in germany.
Was yours a tethered balloon? This is what I am contemplating. I live in a valley such that I can barely read one repeater 10 km away and have no connection to a digi repeater 6 km away.
@dl5psy Mine was tethered yes, but not acting as a repeater but rather as an ordinary station.
@dl5psy It was effectively an HF vertical antenna using the ground as the ground plane