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Is a Balun Needed?

IMG_6164bcr2Yes, a balun is needed.

All balanced antennas such as dipoles, Yagis and hexagonal beams 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 hexagonal beam. 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 and MFJ also make 1:1 choke baluns that are completely satisfactory.

On our hexagonal beams, 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. If the balun case is metal or if ferrite bead units such as ours are used, they should be electrically insulated from the center post.

Our ferrite bead baluns are available in different sizes to fit your cable. All of our kits contain six 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.IMG_6289

Note that the coax connectors outdoors should always be wrapped with an appropriate sealant or rubberized tape to keep moisture out of the cable.



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