so ive been running an inverted V for 40m for probably three years now, apex at around 35 feet off a push up mast in the backyard. it works, cant really complain too much, but ive been reading a bunch of stuff lately about how a flat top dipole at the same height supposedly has better low angle radiation for dx and im starting to wonder if im leaving something on the table.

the problem is my lot is pretty narrow so getting both ends up high enough for a true flat top is kind of a pain. i could probably manage 25 feet on one end tied off to the fence and maybe 28 on the other end going to the shed. so not exactly flat but closer than what i have now. my current feedpoint is at 35 so the ends of the inverted V are drooping down to maybe 10-12 feet above ground.

is the difference actually noticeable in practice or is this one of those things thats like 2dB on paper and you'd never hear it in a real qso? genuinely curious if anyone has done a side by side or switched between the two setups.

honestly the difference between an inverted V and a flat top at those heights on 40 is pretty marginal in practice. yeah the flat top theoretically has a lower takeoff angle but your ends at 25-28 feet are still not high enough to really take advantage of it — you generally want the ends at least 0.1 wavelength above ground for the pattern to clean up nicely and on 40m thats like 14 feet so you're probably fine either way.

what kills the inverted V more than the geometry is when the included angle between the legs gets too narrow. if you're at 35 feet apex and your legs are only dropping to 10-12 feet and the span is reasonable you probably have a decent angle. anything below like 90 degrees and the feedpoint impedance starts doing weird things and your 1:1 balun situation becomes more important. i ran both configs back to back a few years ago switching between them over a few weeks and honestly couldnt tell much difference on 40 for typical stateside stuff. dx was maybe slightly better flat but we're talking like half an S unit on a good day, not some revelation.

im in kind of the same boat, narrow lot and all. what i ended up doing was a compromise — kept the inverted V but added a loading coil arrangement to try and lower the resonant frequency a bit and experiment with the pattern. didnt really work the way i hoped lol. anyway the point is dont overthink it too much. 40m is forgiving. if you really want to improve things on dx the bigger win is probably a better feedline situation or getting the apex up another 10 feet somehow rather than fussing over flat vs inverted.