Model 1235 - 1:2 Unun (25 to 50 ohms) 5kW --- Call for availabilty

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25 ohms unbalanced to 50 Ohms unbalanced

Unlike Baluns, Unun's (unbalanced to unbalanced) provide impedance transformation for antennas that are naturally unbalanced because of their design configuration. Even though the unun's appear small is size, they are able to handle very high power.  This unit is excellent for matching antennas such as inverted L's and other unbalanced antennas with low feedpoint impedance.  Please note that because of the way this unun must be wound, it can only be configured with studs on top as shown in the images above. It should be noted that the manner in which ununs must be wound provides NO common mode or RF choking impedance.

Windings for this model feature custom HAND made coax to provide high power capability at low impedance.  Although not readily apparent, this unit is a very complex and time consuming build, consequently production time can be one week or longer.  Please take this into consideration when ordering. 

Other unun ratios are available by contacting us via the methods shown in the About Us section.

This is a specialty wind and due to the custom nature of this unit, is not eligible for exchange or return unless there is a defect in materials or workmanship.


  Core Material   Custom mix low permeability ferrite by Fair Rite Products for maximum bandwidth.
  Core is coated and sealed for long term durability.
  Winding Type   Single core wound with hand made, low impedance bifilar coax pair configured as 1:2 unun.
  Winding Material   Hand made low impedance coax rated 5kW  
  Power Rating   1.5 to 35 MHz - 5kW
  Useable Frequency   1.5 to 35 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   Weight 1lb 3oz

Installation Notes