Excellent broadband balun that can be used anywhere there is a need to transform 100 ohms balanced to 50 ohms unbalanced. Its most common use is at the feedpoint of quads and mono band loops allowing the elimination of matching networks. This is a two stage unit with a 100 ohm balun wound on a large toroid for RF choking and balanced to unbalanced conversion. The output of the balun is then fed into a second stage which is a 2:1 unun to provide impedance reduction to 50 ohm unbalanced feedline.
This balun is intended for use with monoband antennas at 100 ohms. If used in multiband operation, core saturation and possible failure can occur at high power levels.
Note that a multiband quad is considered a monoband antenna since each band utilizes a separate monoband/resonant antenna.
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Tests performed with AIM-4170uhf Network Analyzer and precision 200 ohm non inductive load.
|Core Material|| Custom mix low permeability ferrites by Fair Rite Products for maximum bandwidth.
Cores are coated and sealed for long term durability.
|Winding Type||Two separately wound large toroids. First is 1:1 balun at 100 ohms. Winding is 14 gauge Thermaleze wire inserted in teflon tubes to achieve the characteristic impedance of 100 ohms. Second large core is trifilar wind of thermaleze wire creating a 2:1 Unun providing the impedance transformation from 100 ohms to 50 ohms unbalanced.
|Winding Material|| Essex heavy build polyamideimide Allex 240 Winding Wire
Windings are inserted into Teflon tubes increasing total breakdown to >10,000 volts.
|Power Rating|| 1.5 to 54 MHz - 3kW continuous.
All ratings based on resonant load. High SWR will reduce power handling ability.
|Useable Frequency||1.5 to 31 MHz|
|Insertion Loss||Less than 0.09db|
|Connectors|| SO-239 connectors are silver plated 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