| Do I need a choke balun with my hexagonal beam? |
KIO Technology
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Yes, you do.
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 over the coax 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 right at the input of the antenna on the center post at the top and
physically strapped to the center post with cable ties. 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 choke baluns are insulated from the metal center post by the heat shrink which covers the beads.
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 over the coax 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 right at the input of the antenna on the center post at the top and
physically strapped to the center post with cable ties. 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 choke baluns are insulated from the metal center post by the heat shrink which covers the beads.
Ferrite beads that slip over
1/2 inch cable such as
RG213, RG8, 9913 or
LM-400.
1/2 inch cable such as
RG213, RG8, 9913 or
LM-400.
Heat shrink used to cover the ferrite
beads and hold them in place on
the cable as shown to the left.
beads and hold them in place on
the cable as shown to the left.
| KIO Choke balun, BAL-8 (Fits up to 1/2 inch cable).......$24 Free shipping when ordered with a KIO hexagonal beam |
Note that the coax connectors should be wrapped with an appropriate sealant or rubberized tape to keep moisture out of the cable. You can see
the balun parts before assembly below and two sizes are available from us.
Ferrite beads that slip over 1/4 inch
cable such as RG-58, RG-8X,
LM-200
cable such as RG-58, RG-8X,
LM-200
Heat shrink used to cover the ferrite
beads and hold them in place on
the cable as shown to the left.
beads and hold them in place on
the cable as shown to the left.
These choke baluns can be used as "line isolators" anywhere along the cable to prevent current flow from induced RF fields.
| Cable and coax connectors are not included in the choke balun kits. |
| Cable and coax connectors are not included in the choke balun kits. |
| KIO Choke balun, BAL-58 (Fits 1/4 inch cable).........$19 Free shipping when ordered with a KIO hexagonal beam |
Hours: Mon - Fri 8:30 - 5:00 CT
Sales & Support: 1-888-694-3923 (Toll Free)
E mail: kio@k4kio.com
Sales & Support: 1-888-694-3923 (Toll Free)
E mail: kio@k4kio.com