Well 100km is very relative to say, but given a good line of sight I think 130W of RF power should be able to cover that distance. God I wanna try that. Too bad it's illegal and an appropriate power transistor will cost a few hundred bucks or so :/. Okay so basically the RF amp is comprised of two stages, the first can be viewed as a common base driver stage, and the second stage is the power amplifier. The efficiency is not very good, at around 40% but with the right transistor and heatsink it shouldn't matter. The input power required for the full 130W is 2W.
