so i finally stopped being lazy and just built a simple 40m dipole out of some 14 gauge stranded wire i had sitting in the garage. cut each leg to about 33.5 feet, fed it with some RG-8X i had leftover from a previous project. center insulator is literally just a piece of PVC pipe with holes drilled through it, nothing fancy at all.

anyway got it up in an inverted V config, apex is maybe 30 feet up on a pushup mast in the backyard. SWR is sitting around 1.8:1 at 7.150 which honestly isnt terrible but i was expecting to get closer to 1.3 or so before i started trimming. the thing is im not sure if its the feedpoint connections causing issues or if i just need to keep shortening the legs. i soldered the coax braid and center conductor directly to the wire ends at the PVC insulator, no balun or anything like that.

should i be worried about the lack of balun here or just keep trimming first and see what happens? i can get SWR down to about 1.5 at 7.200 if that helps narrow anything down. havent tried to really tx much yet, mostly just listening and checking the SWR across the band.

the 1.8:1 isnt bad at all for a first build honestly, most tuners will handle that no problem and depending on your rig it might not even complain. but yeah the lack of a balun is something to think about, especially with an inverted V because the feedline is basically hanging right underneath the antenna and common mode current on the coax shield can mess with your pattern and also make the SWR readings a bit jumpy or weird. you might be chasing a moving target if the feedline is radiating along with the antenna.

a simple choke balun made from winding the coax into a coil of about 8-10 turns right at the feedpoint can help a lot, doesnt have to be fancy. or even a 1:1 current balun if you have one kicking around. try that before you trim more, because once you cut the wire shorter thats kind of it unless you have more to splice in. if the SWR actually shifts or improves after the balun thats your answer on whether common mode was the culprit.

i built almost the exact same thing last spring, PVC center and everything. mine was reading high too and i ended up trimming like 4 inches off each side before it settled down near resonance. but the guy above is right about the balun thing, i added a coax choke after the fact and the SWR actually dropped a bit on its own which was kinda surprising. the feedline was definitely doing something it shouldnt have been.

also 30 feet isnt a ton of height for 40m, the angle of the legs on an inverted V affects the impedance too so it might not hit 50 ohms perfectly even when its resonant. some people use a 4:1 balun for inverted V's for that reason but honestly at 1.8 i wouldnt stress too much, just key up and make some contacts and see how it performs. you can always tinker more later.