so i finally got around to building a simple half wave dipole for 40m, been putting it off forever because i kept thinking it would be more complicated than it was. cut two legs at about 33 feet each, used some 14 gauge stranded wire i had laying around from an old project, and threw together a feedpoint out of a piece of pvc with a SO-239 mounted on it. fed it with RG-8X down to the shack.

here's my thing though — when i put the antenna analyzer on it the resonant point came in a bit high, like around 7.4 MHz instead of down in the phone portion. i trimmed maybe 6 inches off each side and it barely moved. do i need to take more off or is there something else going on? its an inverted V configuration if that matters, apex is about 30 feet up in a pine tree and the ends droop down to maybe 8 feet off the ground. SWR at 7.2 is reading about 1.8:1 which honestly isnt terrible but id like to get it a little lower if i can.

also wondering if the PVC feedpoint is going to cause me problems long term, i live in the midwest so we get some weather here. didnt do anything special to seal it up yet.

the inverted V geometry definitely affects resonant length compared to a flat top dipole, the legs being at an angle kind of compresses things electrically so it usually ends up a bit shorter than you'd expect from the textbook formula. 1.8:1 at 7.2 isn't really worth losing sleep over honestly, most rigs and tuners will handle that no problem. if you want to trim more just do it in small increments, like 2-3 inches at a time per side and recheck. going too short is more annoying to fix than going too long.

the PVC feedpoint is totally fine, lots of guys run those for years. i'd maybe hit the SO-239 and any exposed connections with some self-amalgamating tape or even just a blob of silicone from a hardware store tube. keeps the moisture out of the connector and that's really all you need to worry about. the pvc itself handles UV and weather pretty well as long as its not like, sitting in standing water or something.

yeah i built almost the exact same thing for 40 last year, inverted V off a push-up pole. mine came in high too and i ended up trimming quite a bit more than i expected before it settled where i wanted it. the formula gives you a starting point but real world is always different depending on height, what's underneath it, nearby objects etc.

one thing i did that helped was solder a short pigtail of wire to each leg at the feedpoint so i could wrap extra wire around it and add length back if i cut too much. kind of a pain but saved me once when i got a little aggressive with the cutters