ok so this has been driving me insane for two weeks. running a rush tank solo vtx on my 5inch, set to 400mw, using a pagoda on the quad and a pair of spironet on my goggles (fatshark attitude v6). everything looks perfect on the bench, signal is rock solid in my backyard, but as soon as i get past maybe 150-200 meters it just drops. like fully drops to static and then comes back when i turn around.

ive already reflashed the vtx firmware, tried different channels, checked my solder joints on the antenna connector, and tried a second pagoda i had laying around. same problem both times. the vtx is getting a solid 9v from a dedicated bec so i dont think its a power issue. at this point im wondering if im just doing something fundamentally wrong with antenna matching or something but i have no idea how to even diagnose that

400mw should absolutely not be cutting at 200m under normal conditions so somethings wrong. first thing id actually check is whether the sma connector on the vtx itself is making proper contact - ive had issues before where the center pin was slightly recessed and it looked fine visually but wasnt making full contact with the antenna. also have you verified the vtx is actually putting out 400mw or is it possible it defaulted back to 25mw after the reflash? some of them do that and the pit mode led looks the same

the other thing, and i know you said you checked solder joints, but the pagoda specifically has a really fragile connection where the coax meets the antenna body. if thats even slightly cracked internally you can pass a bench test and still get garbage range. try a different antenna type entirely, even just a cheap linear dipole, to rule out whether its the pagoda specifically.

what goggles module are you running? attitude v6 has a built in receiver but its not great, if youre not using a module bay receiver you might be hitting the ceiling of what those onboard receivers can do rather than a vtx problem. i had almost this exact situation and turned out my goggles receiever was just kinda dying