The J-pole antenna was first invented by Hans Beggerow (the chap in the background) in 1909 for use in Zeppelin airships. He intended the aerial to be trailed behind the airship so it consisted of a single element, half wavelength radiator with a quarter wave parallel feedline tuning stub. This concept evolved to a J configuration by 1936. Interestingly, when the radiating half-wave section is mounted horizontally, at right-angles to the quarter-wave matching stub, the variation is typically called a "Zepp" antenna.
J-Poles are close relatives of Slim Jims... as conceived by Fredd Judd , G2BCX, many years ago. J Poles and Slim Jims are almost identical in looks and performance but when made from ribbon the Slim Jim is simply easier to make. Bantenna Travellin' Jims are designed to roll up and be easily carried BUT....whereas we could make them from 300 ohm ribbon these aerials twist and turn in the wind and SWR fluctuates. Our 450 ladder construction isn't quite as foldable due to the solid copper core, but ther are a bit more ridgid and the SWR is a bit more stable. The picture shows one in a tree...can you see it? Not easily thats for sure. That's how low profile they are. But they work! We currently have 2m versions only but 4m versions are on the workshop bench.