The ubiquitous J-pole is not them most intuitive antenna in the world. Gary Rondeau, AF7NX, explores the J-pole using the 4NEC2 modeling program to shed some light on this common design. Modeling the J-pole
Nice info. The Wikipedia page on the J-Pole is in pretty good shape, mercifully short (encyclopedic), exceptionally well referenced (for a Wikipedia article), and is the goto place to learn past and current details. https://en.wikipedia.org/wiki/J-pole_antenna
Interesting read at the WIKI link. Apparently 6 pounds of copper pipe can be made to radiate, but there is NO advantage over a 19 inch long vertical piece of 12 gauge bare copper wire.
It sounds like a VHF version of the Double Bazooka dipole, lots of smoke and mirrors. I built one decades ago from 450 Ohm ladder line and hung it indoors from an attic roof rafter to access the old DX cluster and some friends on Simplex. It did the job but my hilltop location did most of the work. A ground plane for 2M (and 135 cm) was built from PVC plumbing parts and #10 solid, I didnt have any 12 handy. They were mounted just above the roof line, about 6' apart, and far outperformed the J in many Simplex comparisons during VHF contests. Carl
End fed Zeppelin antenna.... Dont ask what you can do with a J-pole Ask what a J-Poler can do for you
Two potential advantages of the typical J over 1/4 wave GP: Slightly higher gain... not much, but measurable and repeatable. Robust DC ground antenna design.
If one person started selling all the snake oil antennas under one name he could get real rich real fast. Add "Miracle" to the names for another boost.
