ok so this has been driving me crazy for a couple weeks. i have a 400mw vtx on my 5 inch and the video feed looks totally fine when im stationary on the bench or close range in the backyard but as soon as i get out past maybe 150-200 meters i start getting really bad breakup, like not gradual degradation but these sudden hard drops that come back after a second or two

the weird part is my buddy flies a similar setup at the same spots and doesnt have this issue at all. his vtx is a different brand though, he's running a happymodel and mine is a rush tank III, both supposedly 400mw on the same channel. we've checked for channel conflicts, thats not it

im running a lollipop on the vtx and a pagoda on the goggles side which i know isnt ideal matching but i never had issues before with this combination. been using this setup for probably 8 or 9 months and the problem just kind of appeared after i replaced the vtx after a crash. so either the new vtx is defective or something is off with the antenna situation or maybe i wired it wrong, the solder joints look fine to me but i didnt actually check power output with a meter

before i buy anything new or tear the build apart is there a quick way to actually test if the vtx is putting out what it claims

the fact that it appeared after replacing the vtx and your buddys identical-ish setup is fine pretty much points at the vtx itself or how its installed. first thing id check is whether the antenna connector on the new vtx is actually fully seated and not cross threaded, ive seen that cause exactly this kind of intermittent dropoff rather than just flat bad signal. also worth checking if the vtx has any heat issues, the rush tank can throttle output when it gets hot and if its tucked in tight with no airflow thats sometimes enough to cause it

to actually measure output you need an rf power meter or a spectrum analyzer and most people dont have one at home. some local hobby shops or rc clubs have one you can borrow. otherwise the practical test is just swap in a known good vtx and see if the problem follows the vtx or stays with the quad

lollipop to pagoda mismatch can loose you a few db but it shouldnt be causing that kind of hard dropout at 200m with a 400mw vtx, especially if it was working fine before. id bet on the vtx being either slightly defective or the sma connector isnt making clean contact. also just double check your vtx isnt set to 25mw somehow, ive done that more times than i want to admit after flashing firmware