In an effort to provide a 4:1 current balun with the tolerance of the model 4113 and the transformation attributes of the model 4115, Balun Designs has developed the model 4114ocf. By utilizing our stacked core technology, we created a 4:1 current balun that easily tolerates the imbalance caused by the proximity of large structures and metal roofs while still providing good choking impedance, excellent transformation and high power capability. This balun comes as shown with SO-239 connector, an eyebolt on each side to handle the stress of the wire elements and one eyebolt on top to support the antenna and feedline.
Important Note: This balun is designed for and intended for use with antennas that are subject to a compromised install and used with high power (800-1500 watts). If your antenna is in the clear with no roof lines or structures to worry about, the models 4115 or 4116 would be better choices.
Additional RF connector types are available in the Accessories Category under Alternate Connectors.
This balun is an excellent step up from the model 4113 and not as sensitive as the model 4115ocf. If you like to run high power, but need to erect your OCF dipole with a leg over or near your house, barn, garage or metal building, this is the balun of choice. The stacked cores double the choking and isolation while retaining the forgiving nature of windings on a single core.
Installation Note: design of this unit is intended for OCF antennas being used at high power levels (700+ watts) in "comprimised" installations such as those installed over a roof, near large structures or large metal structures/roofs. In extreme cases at very high power levels it may be necessary to combine this balun with a model 1116d. This additional unit can be installed at the feedpoint of the antenna to eliminate any common mode currents on the feedline or at the transmitter end of the feedline to remove any common mode currents before equipment. OCF antennas used at or below the 700-800 watt power level should use the model 4115ocf with no additional choke balun required. The model 4115 can also be used at very high power levels when OCFD is installed in the clear and at least 40-50 feet from the nearest large structure.
Click to Enlarge
All testing done with an AIM-4170 uhf Network Analyzer and precision 200 ohm load
Note: This 4:1 current balun is NOT the type used for an Original Windom which has a vertical coaxial radiator.
The Model 4125 should be used to allow RF to pass to the vertical radiator.
There are a number of interesting designs for OCF dipoles available on our website under the
Antenna Design links listed in the "Support / Downloads" tab at the top of the page
|Core Material|| Custom mix low permeability ferrite by Fair Rite Products for maximum bandwidth.
Large 2.4 inch cores are coated and sealed for long term durability.
|Winding Type||Stacked cores with wire pairs wound as 4:1 current balun.|
|Winding Material|| 2 bifilar windings of 14 gauge Heavy build polyamideimide Allex 240 Winding Wire.
Windings are inserted into Teflon tubes increasing total breakdown to 10,000 volts.
|Power Rating|| 1 to 35 MHz - 5kW, 7kW intermittent. 35 to 54 MHz - 5kW.
All ratings based on resonant load. High SWR will reduce power handling ability.
|Useable Frequency||1 to 54 MHz|
|Insertion Loss|| Less than 0.2db
|Connectors|| SO-239 connectors are gold center conductor with Teflon insulation.
Studs and eyebolts are 1/4 inch.
Alternate connectors and Mounting Options are available in the Accessories section.
|Hardware||All Stainless Steel|
| Enclosure Type
|| NEMA rated 4x marine grade junction box for outdoor installations.
Cover utilizes integral neoprene gasket for weatherproof integrity.
|Dimensions|| 4x4x2 inches for main body of unit
Dimensional Drawing of Standard Enclosure
|Additional Info|| Very high efficiency.
Will not heat up or saturate at like many of the "less expensive" designs.