An ULRS user has achieved 40 km distance with telemetry, and says he was only limited by his plane’s autonomy. His setup is the following :
Normal Orange 1W modules without increased power (3.3V operation, about 400 mW power)
Where to find these antennas ?
If you want to go still farther
Given that the user did 40 km with a 4 elements yagi (something like 7.6 dBd = 9.75 dBi), using this last 12 elements yagi would provide a gain of 14-7.6=6.4 dB or more than double the distance (80 km).
In addition, running the RFM module at 5.5V would go from 400mW (26dBm) to minimum 800mW (29dBm), which gives 3 dB, or 40% more distance.
So it should go to 80 * 1.4 = 112 km. And given that the user said 40 km was not the system’s limit, but his plane limit, the maximum distance is still more…