Well I hadn't found much information on how much RF power was being used on the flights that I had read about which is why I set up the test circuit. Same with the multiple bands. I wasn't planning on putting more than one low pass filter in the system but may just go with 2 bands and put a trap filter in the antenna wire using SMD components.
I agree the 10mW appears to work quite well. I had at one point set the Si5351 at its lowest power level and put a resistor network on its output to get 1mW on the antenna. I was still getting reports over 4000km away.
Steve S
Steve S