so ive been putting off building a wire antenna for probably two years now because i kept telling myself id just buy something decent eventually. anyway last weekend i finally just grabbed some 14 gauge stranded copper wire i had in the garage and cut two legs for 40 meters using the standard 468/f formula, came out to about 33.something feet per side. center connector is just a SO-239 i pulled off an old project, soldered the two legs on, threw it up in an inverted V config with the apex maybe 25 feet off the ground off my chimney bracket.

problem is the SWR at the feed point is reading around 2.1 at 7.150 and i was kind of hoping for better than that. i know 2.1 isnt the end of the world but i was expecting closer to 1.5 or so. did i screw up the formula or is the inverted V configuration just naturally going to push the impedance around? i trimmed a tiny bit off one leg experimentally and it didnt seem to change much. running it into an IC-7300 with the built in tuner engaged it plays fine but still curious why the base SWR is where it is before the tuner.

also the legs are not symmetric in terms of the angle, one side has more droop than the other because of where my anchor points ended up. could that be throwing things off or is it not that sensitive to that

the asymmetric droop is probably contributing a little but honestly 2.1:1 on a homebrew inverted V with those mounting constraints is pretty normal. the inverted V configuration by itself lowers the feed point impedance compared to a flat dipole because of the angle the legs make -- closer they are to vertical the more it departs from that classic 72 ohm theoretical. at 25 feet apex and typical backyard droop angles you're often looking at something in the 50-60 ohm range which should actually match pretty well to 50 ohm coax, but ground proximity and the environment around the antenna shifts things around more than people expect.

i'd try resonating it first by trimming for minimum SWR without worrying about the target frequency, just find where the dip actually is. if its resonant way below 7.150 then you cut too long, above means too short. also what length coax are you running and is there a choke balun at the feed point? no balun means common mode current on the coax shield which can really mess with your readings and also pull the resonant point around depending on how you routed the feed line.

yeah i had basically the same experience with my first homebrew dipole, drove me a little crazy. turned out my coax was acting like part of the antenna because i didnt have a balun and the SWR was jumping around depending on where i touched the coax. slapped a 1:1 current balun on there (wound my own on a toroid, FT-240-43, about 8 turns) and it settled right down. not saying thats definitely your issue but worth ruling out before you start obsessing over the wire lengths