Is a Balun Needed?

IMG_6164bcr2Yes, a balun is needed.

All balanced antennas such as dipoles, Yagis and hexbeams that are fed with unbalanced feed lines such as coax, require a choke balun. Without a choke balun, common mode RF currents flow on the outside of the coax making the feedline act like another antenna. The radiated RF power this causes will tend to distort the front/back performance or front/side performance of your hexbeam. A simple way to greatly reduce this is by use of a good choke balun.

There are several approaches to a choke balun but we recommend the use of ferrite beads on the coax cable itself. A very inexpensive unit such as the ones we sell are quite effective. Other manufacturers such as DX Engineering, Palomar Engineering and MFJ also make 1:1 choke baluns that are completely satisfactory.

On our hexbeams, we recommend that the choke balun be located at top of the center post and physically strapped to the center post with tape or velcro.

Our ferrite bead baluns are available in two different sizes to fit your cable. All of our kits contain five ferrite beads and are generally the same electrically; it’s just a matter of the size of your cable. Make your selection of which size ferrite bead choke balun you need in our store.

Note that the coax connectors outdoors should always be wrapped with an appropriate sealant or rubberized tape to keep moisture out of the cable. The photo above shows the coax connector without sealant.

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