I flew a Squawkbox 50mw t-hunt transmitter under one of my UAVs, (drone) and I got reports from about 20 miles away.
I had fun and several hams commented that they had not heard of doing that before. Balloons are great, but the drone comes right back down where it launched from. Time aloft is about 15 minutes or so. https://youtu.be/pbqCea4zzNE