N7TGB J-Pole
My J-Pole antenna. This is the antenna I use for most of my public service and emergency communications work. It takes only a few minutes to set up or take down and can be stored/transported in a small area, like the back seat of my little car. It was built using the plans on the resource page: Copper pipe J-Pole Plans
This is a close-up view of the SO-239 connector. It is perhaps the trickiest part of building this antenna, as one has to be very careful not to overheat it when soldering to the copper pipe. The most durable way to attach it is to silver solder it , so a Teflon connector (silver plated if possible; I couldn't find one) is desired. The Teflon will withstand the higher heat for a short time, whereas the insulation on the standard connectors will rapidly melt. After soldering, I put a layer of Silicon Rubber caulk over it for additional protection. The wire is placed so as to obtain the lowest VSWR in the center of the frequency range, then silver soldered and taped.
A photo of the broken down antenna, with a yardstick as a reference. This antenna has undergone several modifications in the years I have used it. Originally, the active portion was one entire piece, making it over five feet in length. Additionally, the base was made from PVC pipe.
The first modification I made, was to break the active section into two pieces to make it more manageable. I got the idea from a recent QST article, where the author made a folding J-Pole using bungee cord (like a tent pole). Knowing how easily the copper fittings he used would bend, I felt threaded fittings would be more durable. You should be able to see the joint in this picture and the next one.
The most recent modification I made was as a result of an unfortunate incident at a public service communication assignment. I was breaking down the antenna, and dropped one of the PVC base sections. It hit the pavement and snapped in half at the T coupling. It's just as well, as I have been getting a little concerned with the durability of the threads on the PVC sections, and this gave me an excuse to "upgrade." It also was a convincing reason to give my wife so I could buy another ten foot section of 1/2 inch copper pipe and some fittings.