so ive been putting this off for months but finally sat down last weekend and built a simple 40m dipole out of some 14 gauge stranded wire i had sitting around. cut each leg to about 33.5 feet based on the 468/f formula, soldered it up to a SO-239 chassis connector i had in the junk box, fed it with about 50 feet of RG-8X coax. suspended it in an inverted-V config with the apex at maybe 30 feet off the ground using a fiberglass push-up mast.

heres the thing though — when i sweep it with my nanovna the resonant point is sitting around 6.9 mhz and the SWR at 7.150 is like 2.8:1 which isnt terrible but i feel like it should be better. i trimmed a couple inches off each leg and it barely moved. not sure if its the wire type, the inverted-V angle, or if my center insulator / feedpoint situation is sketchy. the legs are drooping at maybe 120 degree included angle, give or take. ran the coax straight down from the feedpoint without a choke or anything.

anyone else gone through this tuning pain with a first build? i feel like im missing something obvious

the no-choke thing is almost definitely part of your problem. without a common mode choke at the feedpoint the coax shield becomes part of the antenna and it throws off your measurements and your pattern. easiest fix is just wind like 8-10 turns of the coax in a coil about 6 inches in diameter right at the feedpoint, tape it up good. or if you have a few ferrite toroids lying around slap together a quick 1:1 current balun. once i did that on mine the SWR reading on the nanovna actually settled down and i could trim properly. also 120 degrees included angle is on the wider side for an inverted-V, some guys say that pulls the resonant freq up a bit compared to a flat dipole, others say down, honestly ive seen it go both ways depending on height and ground conductivity. id fix the choke situation first before you keep trimming or youll chase your tail all day.

yeah what he said about the choke is right. also just double checking — you measured each leg seperately before you put it up right? i made the mistake on my first one of measuring the total wire length and then cutting it in half instead of cutting two individual legs and i ended up with a slightly lopsided dipole which was a headache. probably not your issue but worth mentioning. 2.8:1 isnt even that bad honestly for a first build, a tuner will handle that easy if youre running a rig with one built in.