so ive been putting off building my own antenna for like two years now because it always seemed more complicated than it probably is. finally just sat down last weekend with some 14 gauge stranded wire i had in the garage, a SO-239 chassis connector, and a piece of PVC pipe for the center insulator. cut it for 40m using the 468/f formula so each leg came out to around 33 feet 4 inches or so.

my question is about the feed point. i just twisted the wire ends through the holes i drilled in the PVC and soldered them to the connector. its been raining since i finished so i havent raised it yet but im wondering if i should be putting some kind of sealant over the solder joints or if thats overkill. also using 50 ohm coax obviously but wondering how much of a mismatch im actually going to see in practice, i know dipoles are theoretically 73 ohms but everyone says just use the tuner anyway.

the other thing is i originally wanted to do an inverted V because my only real support is a 30 foot mast in the middle of the yard. the ends would end up pretty close to the ground on 40m, maybe 8 or 10 feet. is that going to kill the takeoff angle too much or should i just go flat top and run the ends to fence posts at like 6 feet?

the sealant question — yeah do it, self amalgamating tape is what most people use and its cheap. coax seal or even just a few wraps of regular electrical tape over self-fusing tape works fine. water getting into that center connector is the number one way to slowly ruin your SWR over a season and you wont even notice at first.

on the inverted V vs flat top thing for 40m with those heights, honestly at 30 feet center and 8-10 foot ends the inverted V is still going to work. youre not going to be winning any DX contests with it but for general use it puts out a decent signal. the takeoff angle will be higher than ideal but on 40m at night when the band opens up youll still be getting out. flat top at 6 feet on the ends is probably worse honestly, the whole antenna is just too close to ground. id go inverted V.

73 ohm feedpoint impedance is close enough to 50 that you might get away without a tuner depending on how well you cut it. if your radio has a built in tuner it'll handle it no problem. nice work just going ahead and building it, most people talk about it for years.

yeah what he said about the tape. i actually use a combination of coax seal putty and then a layer of self-amalgamating over the top, probably overkill but my last outdoor connector that I didnt seal properly was basically green soup inside after one winter so now im paranoid about it.

one thing i didnt see you mention, are you running the coax away from the antenna at a right angle for at least a wavelength or so? if you just let it droop straight down from the feedpoint it can act as part of the antenna and mess with your pattern and potentially bring RF into the shack. most people use a 1:1 choke balun right at the feedpoint or at least a bunch of coax wound into a choke coil. for a first dipole its not going to make or break you but its worth knowing about for when you start wondering why the SWR is weird.