Im confused on the J-Pole calculations. I calculate mine was 3/4 y = 13.36' (About 14 feet, tip to mast) Phasing U = 4.45 feet, with a 8.91 foot stinger off one leg of the U.
John, you wanted to know what I built, best from memory 10 years ago, with fresh calculations. What I made is a supersized Ringo Ranger II. 5/8 over 5/8 with 1/2 wave phasing, with ground plane 1/2 wave below. The donor was a 5/8 CB antenna that had the coil fried, but tapered tubing to nearly the exact length. I calculated 11.13 feet for each 5/8 wave segment. I used a fiberglass ski pole yard sale (2 for $1) along with fiberglass electric fence posts to make the center insulator and Plus sign shaped horizontal support bar for the hairpin phasing loop. I used aluminum radio shack wire for the phasing loop, 8.91 feet long, folded into a hairpin, spaced 1" apart on plastic milk jug spacers, then siliconed to the wire and spacers onto the support bar. Wound phasing hairpin into a @ looking circle. I wrapped 3 or 4 turns around each element end, then clamped with Stainless hose clamp. I fed it with a coil about a 1/4 wave of copper wire, wound on a mason jar, with coax center tapped 1 turn up from ground end at bottom of coil. Was supposed to be a first starting point, got lucky & worked so good I never changed it. Provided a DC ground. I used about 1/2 wavelength (rf length internally) about 5.88 feet in RG8 coax, to the ground plane. Fed with 80' of RG8. Absolutely tops on 52.525 FM!!! After the lightning hit, 8 feet of aluminum wire was never to be found. Only a 6" chunk 150 feet away in the neighbors driveway. I suspect the hairpin made a whopper of a magnetic field just before the wire melted making it push away from itsself. (best theory I got) Good luck!
