so ive been licensed for about eight months now and have just been using a vertical whip that came with my radio but i really want to try building something myself. ive been reading about half wave dipoles all week and i think i understand the basic concept — two equal legs, fed at the center, total length roughly 468 divided by frequency in MHz. im planning to build one for 40m so that puts me at around 66 feet total which is going to be a bit of a stretch in my backyard but i think i can do an inverted V off a tree.

my main questions are around the feedpoint. im planning to use some RG-8X i have laying around and i know i need a balun or at least a choke to keep RF off the coax shield but im not totally sure if a simple coax choke (just winding the feedline into a coil) is good enough or if i should build or buy a proper 1:1 current balun. also how critical is the height of the center feed point for 40m — i have a tree thats maybe 30 feet tall so center would be at like 28 feet with the legs sloping down at whatever angle that works out to. ive seen people say anything under a half wavelength high is compromised but not sure how bad were talking for a general purpose HF setup. not contesting just want to get on 40m SSB and maybe some casual CW.

using 14 gauge stranded copper from the hardware store for the wire, is that fine or do i need something specific

the coax choke will work fine for what you're doing, honestly for a backyard dipole on 40m you're not going to notice the difference between that and a fancy wound balun. just do like 8-10 turns of the coax at the feedpoint, keep the coil diameter around 6 inches or so. ive been running dipoles with homemade chokes for years on 40 and 20 and never had a problem worth worrying about.

30 foot apex height for a 40m inverted V is lower than ideal but its not some disaster. you'll have more high angle radiation which actually helps for regional and nearby contacts, NVIS type stuff. if you want to work dx you might struggle a bit but for just getting on the air and having fun on 40m SSB it'll work. the antenna will work. cut it a little long first, like add 6 inches to each leg and trim from there after you check SWR. 14 gauge stranded is totally fine, thats what most people use.

yeah what he said about cutting long first. i learned that the hard way on my first dipole, cut it exactly to the formula and ended up resonant way above where i wanted it. had to splice in extra wire which is a pain. just go long and trim a few inches at a time, takes longer but way less frustrating.

also for the center insulator if you dont want to buy one you can just use a chunk of thick PVC or even a piece of heavy duty plastic cutting board drilled with holes, works just as good. the commercial ones are nice but not necessary at all