so anyway this has been bugging me for a couple weeks now. i built a new 5 inch freestyle quad, running a Rush Tank Solo vtx set to 400mw and the video just goes to garbage past maybe 200 meters. like full static, not even breakup, just completely unusable. i'm on 5.8ghz, using the goggles that came with my starter kit from a while back

the weird part is my old quad on the same channel and same power setting gets way further without issues. both running linear whip antennas, nothing fancy. i cant figure out if i mounted the vtx wrong, if its a heat thing, or if my antenna on the new build is somehow bad. havent checked the swr or anything like that because i dont have the gear for it. just looking for a starting point here

check your antenna connector first, like physically wiggle it while its powered up and see if the signal changes at all. a loose or slightly damaged SMA connection can absolutely cause this and its super easy to introduce during a build especially if you were tightening it against the frame. also make sure the antenna isnt running parallel to any carbon fiber pieces, CF kills 5.8 signal hard and people forget that all the time on new builds

if the connector is solid then yeah could be a heat issue with the vtx throttling output. some of those Rush units get hot fast if airflow isnt great and they'll back off power without telling you. try flying with the props off hovering in place for 30 seconds and see if it still degrades

honestly my first guess is the antenna on the quad itself is either damaged or just oriented badly. 200m dropoff at 400mw is pretty rough and usually points to something physical rather than a vtx problem in my experience. also what goggles are you running, because if theyre old entry level ones the receiver sensitivity might just be way lower than what you had on your other setup and thats why the other quad seemed better