I was reminded by a video by VK3YE about a PA chain he is working on using BD139’s that I had sometime ago thought about using them in a class c amp. I had seen something similar in a schematic for a circuit by Diz at Kits and parts. When you can get a good 5w from a pair of transistors that cost 20 cents and a couple tv baluns, why settle for less in your qrp rigs.