so i finally got around to building a center-fed dipole for 40 meters after putting it off for like three months. used 14 gauge stranded wire i had in the garage, nothing fancy. calculated the length using the old 468/f formula which put me at about 66.3 feet total, cut it just a tiny bit long so i could trim down from there.

got it up in an inverted-v config, apex maybe 30 feet up tied to a tree in the backyard, legs going down at roughly 45 degrees each. fed it with about 50 feet of RG-8X i had lying around. when i threw the antenna analyzer on it the resonant point came out around 6.9 MHz with swr of about 1.4:1 which is fine but id really rather have it closer to 7.2 or 7.25 where i do most of my operating. trimmed about 4 inches off each side and now its resonant around 7.05 but swr climbed to almost 2.1:1 at the dip. feels like im chasing my tail here. is the issue the inverted-v angle or am i just doing something dumb with the trimming process

inverted-v's are a bit tricky because the angle of the legs affects the feedpoint impedance, and at 45 degrees youre already compressing it quite a bit from the flat dipole's nominal 73 ohms. the closer the legs get to vertical the lower the impedance drops, which is why you sometimes see worse swr even after trimming to the right frequency. 2.1:1 isnt terrible honestly, most tuners handle that no problem, but if you want to chase it down further try raising the apex a few feet if you can and see if the legs can be a bit more spread out. also 4 inches off each side total is 8 inches off the overall length which is a pretty decent jump, might try 2 inches per side next time and give it a few minutes to settle before measuring again. what analyzer are you using?

yeah i had almost the exact same thing happen with mine last spring. ended up being that my coax had a nick in the outer jacket right near the connector and it was throwing the readings off a little. probably not your issue but worth looking at the feedline too and not just the antenna itself. also 30 feet apex on 40m inverted-v is kinda low, the antenna wants to be higher, radiation angle is gonna be pretty steep which isnt ideal for DX but for local and regional stuff it works fine