so ive been messing with this for about three weekends now and i cant figure out what im doing wrong. built a simple center-fed dipole for 40m, each leg should be about 33.5 feet based on the 468/f formula, fed with about 50 feet of RG-8X down to the shack. got it up in an inverted-V config with the apex at maybe 30 feet off the ground which i know isnt ideal but thats what the tree allows.

resonance is sitting around 7.4 MHz which is higher than i wanted, swr there is maybe 1.8:1 but down at 7.1 where i actually want to operate it climbs to like 3.5:1. my tuner handles it but something still feels off. i trimmed both legs the same length, connections look clean, balun is a simple 1:1 choke i wound myself on a FT-240-43 with about 8 turns. not sure if the balun is the problem or if i just need to add wire to both legs.

anyone else dealt with this and what did i actually do wrong here

yeah the fix is pretty straightforward, you just need to add wire. resonance being high means the antenna is electrically too short, so add a few inches to each leg at a time and re-measure. the inverted-V configuration also shortens the effective electrical length compared to a flat-top so that factors in too, people forget that. the legs being angled down effectively lowers the resonant frequency a bit but the formula doesn't account for any of that, plus being close to ground has effects, nearby metal, the feedline running near the antenna... it all adds up.

your balun sounds fine honestly, 8 turns on a 43 mix is pretty standard for HF and should give you decent common mode rejection. id rule that out and just start adding wire. also double-check your connections at the center insulator, ive seen more bad SWR readings from a slightly loose connection than from anything else.

3.5:1 at 7.1 with RG-8X over 50 feet isnt catastrophic but yeah i get why it bugs you. one thing that tripped me up early on is measuring at the wrong point — are you measuring at the rig end of the coax or right at the feedpoint? matters a lot especially with lossy coax since it kind of masks whats happening at the antenna. RG-8X isnt terrible but its not RG-213 either.

also what are you using to measure, an antenna analyzer or just the rig's built-in SWR meter? because if its just the rig meter those can be... optimistic sometimes lol