The antenna is made by removing the outer covering of the coax for the length of the top section, flipping the braid back over the outer covering of the bottom section and then trimming the braid to length. All these parts should be readily available from your local electronics parts or ham radio stores. The only things you need to build a Vertical Bazooka are a length of coax, a connector to fit your radio and a length of heat shrinkable tubing. If you like you can also build a self-supporting version by sliding the finished antenna into a length of “Schedule 40” PVC plumbing pipe.
Rg58 magnetic loop free#
With a weight on the free end of your cord, you can simply toss it over any nearby support and hoist the antenna up into the air for use. You can build a mobile “emergency” version of the Vertical Bazooka by attaching a length of non-conductive cord (nylon line) to the top of the antenna. But please notice the formulas shown will deliberately start you off with the top section too long, so you will have to trim it for the best SWR.
You can use the formulae in the diagram above to create Vertical Bazooka dipoles for any frequency. The outer braid couples with the inner braid to form the balun and is thus affected by the velocity factor of the coax. The braid side of the dipole ends up considerably shorter than the top element because of the interaction between the braid and the coax. By folding an electrical quarter wavelength of braid back over the insulated coax we are forming both a dipole and a “bazooka” (sleeve) balun, a coaxial 1:1 balun that greatly reduces feedline radiation. One of the more interesting features is the braid itself. The resulting antenna has a low radiation pattern and an impedance of 55 – 60 ohms. The center lead of the coax forms one half of the dipole and the braid forms the other. The antenna itself is an off-center fed vertical dipole made by flipping an electrical quarter wavelength of braid back over the outside of the coax. Self-supporting versions are easily built.Performance like regular half-wave antennas.Can be coiled up and put in your car trunk.One of the easiest and quickest antennas to build is the Vertical Bazooka, which is made entirely from coaxial cable.īeyond being extremely easy to build, these antennas have several nice features to recommend them: Every radio amateur should build at least one antenna to prove to themselves they can improvise in an emergency.
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