so i finally got around to building a proper dipole instead of just using that crappy whip i had. picked up some 14 gauge stranded wire from home depot and cut it to roughly half wavelength for 40m, used the standard 468/f formula and ended up with about 66 feet total. center insulator is just a piece of pvc i drilled holes through and the coax goes down to my rig through about 50 feet of RG-8X.

thing is im getting a pretty high SWR around 2.1:1 at the frequency i want to operate and i cant figure out if its the height (its only about 25 feet up right now, inverted-V configuration), the wire length being slightly off, or something with my feedpoint connection. i soldered the coax shield and center directly to the wire legs but maybe i did something wrong there. does the solder joint quality actually matter that much at HF? i feel like it shouldnt but who knows

also should i even be worried about 2.1:1 if my tuner can handle it? just want to understand what the actual problem is before i start trimming wire

2.1:1 is honestly not bad for a first build and an inverted-V at 25 feet — that configuration naturally has a slightly lower feedpoint impedance than a flat top because of the angle on the legs, so you're already fighting that a bit. most tuners will handle it no problem but yeah if you want to understand whats going on thats the right instinct.

the solder joint matters more than people think actually, not because a bad joint causes dramatic SWR changes but because a cold joint or a connection thats not fully making contact can cause intermittent issues and weird readings. if it looked shiny and flowed right you're probably fine. one thing i'd check is whether the coax shield braid is fully connected and not just a couple strands touching — ive seen people lose like half their radiated power to a sketchy shield connection and not realize it.

honestly though try raising the apex a few more feet if you can, that alone might bring you down closer to 1.5:1. and dont trim anything yet until you know what frequency its actually resonant at — stick an antenna analyzer on it if you have access to one and sweep it, youll see exactly where the dip is.

yeah what he said about the inverted-V impedance thing is real, i built basically the same antenna last spring and spent two weekends trimming wire before someone told me that. ended up around 50 ohm when i got the angle right on the legs, somewhere around 120 degrees between them i think. your height is also gonna affect it more than people admit, ground reflections and all that.

one random thing — what kind of center insulator did you make exactly? i tried the PVC thing and had some issues with water getting into the drilled holes and causing weird losses in damp weather. eventually just bought one of those cheap egg insulators for the ends and used a SO-239 chassis mount for the feedpoint. way less headache.