okay so ive been running an inverted V dipole for 40m for about two years now, center fed with some cheapo 1:1 balun i picked up at a hamfest, apex at around 35 feet off a pushup mast and the legs drooping down at maybe 30-35 degrees. always worked fine, SWR was like 1.4:1 at resonance and i was happy with it.

last week i finally got around to raising the center point, got it up to just over 50 feet now. figured it would only get better, more height is more better right. but now when i sweep it with my RigExpert the resonant point shifted up maybe 30-40 kHz and the SWR at the bottom of the band is noticeably worse, like 2.8 to 1 down around 7.050. the impedance at resonance looks different too, showing lower than the 50 ohm ballpark i was seeing before.

the legs are still the same length, i didnt touch them. i did have to re-route some of the coax run because of the height change so that's different. also the angle of the legs is now shallower because they're coming off a higher point to the same ground stakes. could that be whats doing this or am i overthinking it. anyone run into this changing the angle on a drooping dipole and having it act different

yeah the angle of the legs absolutely changes the feedpoint impedance, thats pretty normal with inverted V configs. a flatter angle pushes the impedance lower, closer to 35-40 ohms sometimes even less depending on how shallow you go. so your 1:1 balun that was fine at 35 feet is probably not the best match anymore at 50. the frequency shift is also expected since the effective electrical length changes a little with the geometry even if the wire length is the same, something to do with the mutual coupling between the two legs changing as the angle opens up.

try shortening each leg by a couple inches first to bring resonance back down where you want it, then see what the impedance looks like. if it's sitting around 35ish ohms at resonance you might want to try a 4:1 balun or just a 1.5:1 and see if that cleans things up on the low end. also double check your coax run, a poorly seated PL-259 or a drip loop issue can do weird things to an otherwise decent sweep.

i had almost the exact same thing happen when i went from a pretty steep inverted V to a flatter one trying to get more horizontal coverage. the SWR looked totally different and i spent like two evenings convinced my balun had gone bad lol. turned out the impedance just dropped and my old 1:1 wasnt doing me any favors. ended up just cutting the legs down a bit and accepting a slightly worse SWR at the band edges, works fine now. 40m is pretty forgiving anyway if your rig has a decent internal tuner.