Begin with your schematic... and checking that connectors are secure and tight to your EMS module, I assume an SV-EMS-220. Bus voltage should be on pin 1 of the 37-pin connector that feeds the EMS module.
While it is true that increasing the Tx wattage will increase the broadcasting range, it is not linear. That is, doubling the Tx wattage will not lead to a doubling of the broadcast range. The power from a transmitter falls off by the square of the distance. To double the range, one must...
6B or 7B for me. Last year at Sun'N'Fun, a bunch of ad hoc pilots and I, surrounded some Dynon folks asking for essentially option 6. I'll be doing the same this year in a couple of weeks. The recently released training videos are a big help, but I still find myself in the air thinking, "now...
Just another endorsement of flysto... I've been using it since I stumbled across their booth at Sun'N'Fun last year. I showed it to my instructor (I'm a rusty pilot) and it's great for evaluating flights. My instructor now uses it in his own plane. The duplication of flights is a nuisance...